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Part 1 of 2 - Health Facilities Scotland

1. 76mm 54mm 42mm 35mm 0 25 0 5 0 75 1 1 25 1 5 1 75 2 2 25 2 5 2 3 25 3 5 3 75 4 4 25 4 5 4 75 5 0 5 25 5 5 5 75 6 0 6 25 Pressure drop kPa m Version 2 0 June 2001 Page 253 of 264 Borders General Hospital NHS Trust on behalf of NHSScotland Property and Environment Forum SHTM 2022 Part 1 Medical gas pipeline systems Appendix 10 Pressure regulation for 400 kPa medical gases and medical air and 700 kPa systems surgical air Pressure regulation for 400 kPa systems medical gases and medical air The minimum pressure of 355 kPa which must be available at each terminal unit is the minimum required for medical equipment specifically blenders The pressure settings of the line regulators are based on achieving this minimum pressure taking into account the operatiag tolerances of the components Typical pressure relationships are shown in When designing the pipeline distributi ressure loss allowance of 10 including termina minimum plant pressure of 420 k ine p
2. 54mm 3000 54mm Pressure loss 7 2500 at 14kPa DA 21kP Z 1kPa 2000 54mm tA 7 a 1500 Ly ZA A LA A 42mm 35mm 1000 AL 35mm 35mm 28mm 7 28mm 500 28mm rS 0 0 0 25 1 25 1 5 1 75 2 2 25 2 5 Pressure drop kPa m Version 2 0 June 2001 Page 249 of 264 Borders General Hospital NHS Trust on behalf of NHSScotland Property and Environment Forum Free air flow l min 35000 30000 25000 20000 15000 10000 5000 SHTM 2022 Part 1 Medical gas pipeline systems Pressure loss data 22mm 22mm Pressure loss 7kPa 14kPa 34kPa 15mm 12mm
3. WY S O SSOA S OSSOA S aAlesel MewNd aAlesel MewNd amp ole Wo Ny Q wa sAs a UOHIN A SIP aUljadiq QdIAap Jaljas Ajayes yms SS Ad yIMS SS Ad QdIAap jaljad Ajayes S Sd Jaaoabueyo ab i2 e mle Q pasinbas ee Oe pasinbas roe Bully sOpuIAD fr OALA D lt D lt gt q D lt Bui JOPUIAD j AJBA N HO NysS BAJeA UIN d1 UON PIOHUEW AL ak PIOHUE N 40 INYS SAJCA u1n 1 UON 9a LA T T D gt q gt lt K r c Aa O O D A gt 4aAcoaHueyd onewozne yyM saijddns Asepuooas pue Asewlid Hulsiwoidwod Ajddns aasasay OD juawdinba BDIAVP BASIS Ae NDajowW Ajddns Aiepuodseas wajsAs se Ajddns Auepuoses E 01 U09 INSS ld e a q SABA AJLA J0 INYUS N 0 NysS pue Josseidwo QO D gi DE deskjeue ueBAxo 7 il u pu d pul pN P aAle ee 10 ejn b ueg X ei I Q ainsseid yeuondo 8iINSSOJ BOIABP BADIS euoido V d A i aul Kt yoss dwo9 gt lt gt lt P lt O Jenoa N 1941999 19994 gt gt gt q 101S00q y J0 098 UU0D 1 l 4 u a q x 4 SM j ojejnba Y 10 ejn 1 O eee ainsseid e e Aud INSS ld eu OAICA Aud Aud u1n 1 UON teuondo J9 009 J9YV O 4 co ae 2 si a i es ae 4 Ss
4. AA VW i S OK a0 eX s C A pe Upel sgl Saleg legl vy t k X 5 a B l N 4 i q Sa j Pere gt lt l D YX eS z Lee n hy 7 V Ae V HED O FO Ort HO O Version 2 0 June 2001 Page 106 of 264 Borders General Hospital NHS Trust on behalf of NHSScotland Property and Environment Forum 7 90 7 91 7 92 7 93 7 94 7 95 SHTM 2022 Part 1 Medical gas pipeline systems For both the oxygen and nitrogen it is necessary to have a back up system Since it is essential to ensure continuity of supply the system demands are such that this back up should be derived from a second smaller VIE This second back up VIE can also provide the back up to the medical oxygen system thus providing a more realistic back up facility than the cylinder manifolds currently installed Since four VIEs will be required although two of them will be relatively small there will of necessity be space requirements to be considered when planning the installation of a synthetic air system The system comprises a storage vessels one main vessel and one back up vessel for both oxygen and nitrogen b vaporizers for both oxygen and nitrogen c medical oxygen flow control where us dical oxygen systems ply
5. CX X CX l i es i i Ypa zia lt T lt 4 tt y H X A Pr Ji p og Ji J bea i P SP i F 5 3 A Y gt lt V i y e lt gt lt gt ae Q Version 2 0 June 2001 Page 105 of 264 Borders General Hospital NHS Trust on behalf of NHSScotland Property and Environment Forum BACK UP STORAGE VESSEL SHTM 2022 Part 1 Medical gas pipeline systems ENVIRO gure 12 Typical synthetic air layout nitrogen VIE supply with air mixing equipment reproduced by kind permission of BOC Fi cas SUPPLY Tra 7 X EO CH 2i 2i Y IOD xD 9 D Pax MAIN MIXER MAINS POWER FAILURE ON MAIN MIXER MAINS POWER FAILURE ON BACKUP MIXER MAIN VAP OPTIONAL ARRANGEMEN FOR MAIN VAPORISER
6. 0 5 Version 2 0 June 2001 1 75 2 2 25 2 5 2 75 3 Pressure drop kPa m Borders General Hospital NHS Trust on behalf of NHSScotland Property and Environment Forum 3 5 3 75 Page 250 of 264 Free air flow l min 35000 SHTM 2022 Part 1 Medical gas pipeline systems Pressure loss data 54mm 54mm 30000 VA VA Pressure loss 25000 Pa 7kPa 54mm 4 14kPa F Pi 34kPa Z 20000 VA f samm 42mm Y Dr a 4 JA 15000 4 42 LA mm LA 74 Anza PAA vA KA 7 Somm 35mm pA 10000 f 35mm 28mm 28mm 5000 28mm I 0 0 0 25 0 5 2 2 25 2 5 2 75 3 3 25 3 5 3 75 4 4 25 Version 2 0 June 2001 Borders General Hospital NHS Trust on behalf of NHSScotland Property and Environment Forum P
7. Compressed Flammable Gas Cylinders m Gas volume measured as Nm at 1013 mbar and 15 C Up to 70 Above 70 Liquid Oxygen Storage Up to 200 tonnes Separation Distance Me For liquefied flammable gas cylinders see table 1 Distances in Table 2 are bases on hydrogen cylinders Reference BCGA CP8 1986 For separation distance for acetylene BCGA CP6 1986 23 should be referred to TABLE 3 SEPARATION DISTANCES FLAMMABLE LIQUID OR GAS LINES WITH UNION FLANGES ETC AND OXYGEN STORAGE 1 The above separation distances are intended to provide protection for the LOX storage tank against jet flame impingement from an ignited release from the flammable liquid gas line 2 The distances are based on LPG as the contents of the flammable liquid gas line and are given as a worst case 3 For flammable liquids or gases other than LPG in the line the above distances should be used unless it can be shown that smaller distances are adequate to avoid jet flame impingement 4 If some means of protection from jet flame impingement such as shielding of the joint by fire resistive material can be provided between the union flange on the flammable liquid gas line and the LOX storage and this can be shown to provide an equal or greater degree of protection than the separation distances shown the separation distances may be reduced Version 2 0 June 2001 Page 68 of 264 Borders General Hospital
8. he fal flow is based on g bgs not already For a hospital comprising several department 80 l min for the first bed and 1 l min for any assigned to a specific department A factor of 0 75 should be applied to ca d total flow to avoid unrealistically high flows Operating departments e surgi am and anaesthetist it is also ic room jand recovery Vacuum is provided for provided in the anaest d in each operating room Since it is possible 5 Operating room to be in use simultaneously will require 80 l min and each terminal unit should be For anaesth jic rooms it may be assumed that 40 l min will be required at each terminalYunit Where there are several operating suites each comprising one operating room and one anaesthetic room the diversity may be calculated on the basis that for the first two suites no diversity should be allowed that is 240 l min For more than two theatres it may be assumed that 50 of remainder will be in use simultaneously at 120 l min per suite Maternity accident and emergency theatres and major treatment rooms should all be treated as operating rooms Each terminal unit in recovery should be capable of passing 40 I min The diversity of flow is calculated on the basis that vacuum is being used simultaneously at 25 of bed spaces minimum one Version 2 0 June 2001 Page 49 of 264 Borders General Hospital NHS Trust on behalf of NHSScotland Property and Environment For
9. Space should be provided to facilitate any mayoe vehicle Typical turning circle dimensi e a follows of the delivery Coupled length Articulated vehicle 16 5 Rigid vehicle 8 6 Turning circle m 2 27 5 5 20 0 ures 6 and 7 are taken from the BCGA uld be at least 8m from roads drains be concrete and should have free access at a no parking area It should be free from ders and not used as a general storage area The VIE der store It is also important that it is served by a ugh and with turning facilities for road tankers The road nobstructed at all times The safety distances sh pwn in rubbish e Operation During normal operation of the system the valves should be in the positions indicated below Valve ref description Normal operation To reduce normal pressure Gas withdrawal Closed Open Liquid withdrawal Open Closed Gas isolating Open Open Liquid isolating Open Closed Top fill Closed Closed Bottom fill Closed Closed Version 2 0 June 2001 Page66of 264 Borders General Hospital NHS Trust on behalf of NHSScotland Property and Environment Forum 6 31 6 32 Oxygen is supplied to the control panel at a pressure of 10 5 bar g where its pressure is reduced to 4 2 bar g before it flows to the pipeline distribution system The control panel comes supplied with the following alarm conditions Standby system in use Should the oxygen supply from the main VIE fail the standby system will auto
10. Scottish He Memor Design insfallation Meg pipeline systems y The contents of this document are provided by way of guidance only Any party making any Disclaimer use thereof or placing any reliance thereon shall do so only upon exercise of that party s own judgement as to the adequacy of the contents in the particular circumstances of its use and application No warranty is given as to the accuracy of the contents and the Property and Environment Forum Executive which produced this document on behalf of NHSScotland Property and Environment Forum will have no responsibility for any errors in or omissions therefrom The production of this document was jointly funded by the Scottish Executive Health Department and the NHSScotland Property and Environment Forum NHSScotland P amp EFEx June 2001 SHTM 2022 Part 1 Medical gas pipeline systems Executive summary An MGPS is installed to provide a safe convenient and cost effective system for the provision of medical gases to the clinical and nursing staff at the point of use It reduces the problems associated with the use of gas cylinders such as safety porterage storage and noise The guidance given in this SHTM should be followed for all new installations and for refurbishment or upgrading of existing installations It is not necessary to apply the guidance retrospectively unless patient or staff safety would be compromised In
11. Borders General Hospital NHS Trust on behalf of NHSScotland Property and Environment Forum 3 19 3 20 SHTM 2022 Part 1 Medical gas pipeline systems Nitrogen for surgical tools BS 5682 does not include a NIST for nitrogen In the absence of a British Standard the NIST connector allocated in ISO 5359 may be used Where nitrogen is provided for surgical tools the NIST connector is recommended with the body forming the wall outlet To avoid the hazard of discharge of stored energy in low pressure flexible connecting assemblies a limited leak check valve should be included in the nipple Version 2 0 June 2001 Page 34 of 264 Borders General Hospital NHS Trust on behalf of NHSScotland Property and Environment Forum 4 1 4 2 4 3 4 4 4 5 4 6 4 4 8 4 9 SHTM 2022 Part 1 Medical gas pipeline systems 4 Gas flow General A schematic diagram of a typical MGPS is shown in the Operational management part 2 of this SHTM This diagram shows the pipeline distribution system from the gas source to the point of use that is the terminal units There are three aspects of gas flow to consider when designing the pipeline distribution system the flow which may be required at each termi b the flow required in each branch of the di system see the schematic which shows a system with i anches c the total flow i e the sum of the flows in ly a diversity factor
12. Single bedroom 1 1 Multi bedroom per bed space 1 1 Nusery per cot space 1 1 provision for 2 cots only irrespective of number of cot spaces p project team option Version 2 0 June 2001 Page 27 of 264 Borders General Hospital NHS Trust on behalf of NHSScotland Property and Environment Forum SHTM 2022 Part 1 Medical gas pipeline systems Scale of provision of terminal units Department Radiology department Special procedures room Anaesthesia room Holding and delivery Ultrasound Fluoroscopy Urography General purpose room Tomography O2 NO N O O MA4 SA7 VAC AGSS 1 1 1 1 1p SN b h h ee ee ee SN h ee ee ee ee ee In patient accommodation Single bed room Multi bed room per bed space Treatment room appropriate for adult acute children and elderly Intensive therapy unit ITU per bed space Equipment service room per work space Coronary care unit CCU per bed space Acute mental illness accommodation ECT room Post anaesthesia recovery per bed space Adult acute day care accomm Treatment room Anaesthetist Surgeon s I I o_o O I s I Endoscopy room p 1 1p 1p 1 1p Fracture clinic Plaster room Oral surgery orthodontic department Consulting treatment room Type 1 Consulting treatment room Type 2 Recovery room per recovery position 1 i 1 Appliance laboratory
13. tail pipe rupture The tail pipe manifold connector should be gas specific In the event of power failure on restoration of the power supply the original running bank should be on line that is the same bank as was the running bank prior to interruption of the supply NOTE Some manifolds default to a specific bank following a power failure regardless of which bank was the running bank prior to interruption of the supply The tail pipe cylinder connector must be a pin index yoke connector in accordance with BS EN 850 for oxygen nitrous oxide oxygen mixture 50 v v and medical air The connector for nitrous oxide should be a side outlet valve connector in accordance with BS 341 PE1 e manifold connectors should be in accordance with the following M26 x 2 O gt 2 M24 x 2 ir M22 x 2 M20 x 2 2 M18 x2 M16 x 2 M14 x2 2 oxygen free purge Pressure indication e ed to indicate pressure in each cylinder bank and in the M Pressure con hould maintain the nominal pipeline pressure within pendix 10 The pres ntr the limits g There should e separate pressure regulating valves for each cylinder bank and the control system should be designed so that the cylinders of one bank can be changed or the pressure regulator for one bank can be overhauled without loss of continuity of the gas supply Pressure safety valves should be of the self closing type and be installed on each distribution pipeline dow
14. 1 2 Other areas 20 QI 20 15 nB 1 Medical air General Medical air is used to provide power for several types of equipment including surgical tools ventilators and nebulisers Oxygen should be avoided as a power source because of fire risk and cost and should not be used where medical air is available unless specifically recommended by the device manufacturer Version 2 0 June 2001 Page 43 of 264 Borders General Hospital NHS Trust on behalf of NHSScotland Property and Environment Forum 4 48 4 49 4 50 4 51 4 52 4 53 4 54 SHTM 2022 Part 1 Medical gas pipeline systems NOTE BS 4272 Pt 3 1988 provides for auxiliary outlets on anaesthetic machines for both air and oxygen Medical air should be provided at two different pressures a a pressure of 400 kPa is required to drive ventilators and for other respiratory applications b a higher pressure of 700 kPa is required to drive surgical tools In this document medical air at 700 kPa is referred to as surgical air to avoid confusion Medical air 400 kPa General The use of medical air particularly for respirat has increased markedly in recent years This service is the icaLof the medical gas services since air powered ventilators ceas oraratiin the event of failure of the supply US Medical air is also directly inhaled also be used to dilute oxygen befo potentially toxic effects of pur ients Wing ventilation
15. 13 88 13 89 SHTM 2022 Part 1 Medical gas pipeline systems Emergency inlet port Medical oxygen and 400 kPa medical air systems should be provided with an emergency inlet port to the pipeline distribution system This should be located downstream from the main source of supply to permit connection of a temporary supply plant The emergency inlet should comprise a lockable valve and blanked gas specific connecting port and should incorporate a non return valve An emergency inlet port is not required for 700 kPa surgical air systems Line pressure alarms and safety valves The purpose of the line pressure alarm is to warn users that the nominal line operating pressure is out of limits and that gas mixtures whether supplied by a blender mixer or by an anaesthetic machine may deviate from the clinical desired proportion Local action can then be taketo adjust the mixture or portable cylinder can be made availab been set to accommodate the desig equipment where differential pres performance h low pressure limits have s of anaesthetic The line pressure safety pressure effects since tfe pres t which maximum discharge occurs will result in a differential much grea er than that for which the anaesthetic equipment has b hey are therefore strictly system protection devices The com f medical gas pipeline line pressure regulators warning and alarm d pressure settings is crucial to performance of anaesthetic lome
16. SHTM 2022 Part 1 Medical gas pipeline systems All MGPS should be left filled with medical air at pipeline distribution pressure until they are filled with the specific working gas shortly before use The medical vacuum pipeline need not be maintained under vacuum Provision should be made for regular running and maintenance of all supply plant during such an interim period Details of the work carried out as well as records of the system pressures should be recorded This information is required in order to demonstrate that the systems have been satisfactorily maintained under pressure during this interim period Tests for particulate contamination should be carried out after the systems are filled with the specific gas The extent of the tests Is at the discretion of the quality controller QC Check that a Danger do not use label is affixed to each terminal unit When the construction contract has finished the ontractor should record the removal of all special connectors and cyli NOTE Special connectors and cylinders maybe re ed to maintain the systems under pressure Each pipeline system mu before use The followi the specific working gas shortly conditioN should apply all sources of tas uste disconnected b s must be removed from site C stem must be at atmospheric pressure with all AVSUs open must be filled to pipeline distribution pressure with the s from the supply system e wit
17. The standby vessel should have 24 hours cayjac set out in the Liquid oxygen ould be fitted with a telemetry In addition to the normal instrumen Supplies section of Chapter system to continuously mani itted direct to the gas supplier and also the hospital The exac much information and where it should be The main vesse level alarm is activated at 25 full the back up low at 50 full ef valves and bursting discs should be sized in accordance Code of Practice The safety with the BC The liquid from the vessels should be supplied to the process at a nominal pressure of 12 5 bar g Vaporisation The main and standby vessels should have dedicated vaporisers designed for continuous capacity and 24 hour capacity respectively at 1 5 x the required flows to ensure that the vaporisers are not overdrawn This may be achieved in each case by either a single set of vaporisers or by vaporisers operated on timed or manual changeover lt is preferable for the vaporisers to operate on a timed changeover as this minimises the maintenance actions which the hospital are required to carry out Version 2 0 June 2001 Page 108 of 264 Borders General Hospital NHS Trust on behalf of NHSScotland Property and Environment Forum 7 107 7 108 7 109 7 110 7 111 7 112 7 113 7 114 7 115 7 116 7 117 7 118 SHTM 2022 Part 1 Medical gas pipeline systems The timed changeover will require a 110V or 2
18. d en supplies to the mixing panels d surgical nitrogen flow control w d u e control panel for the nitrogen f duplicate air mixing panels g buffer vessels each mixeMwss a buiter vessel to smooth fluctuations in demand warning and alarm System on each mixer Vessel summary The following vessels are required a one main oxygen vessel b one standby oxygen vessel with 24 hours capacity c one main nitrogen vessel d one standby nitrogen vessel with 24 hours capacity Version 2 0 June 2001 Page 107 of 264 Borders General Hospital NHS Trust on behalf of NHSScotland Property and Environment Forum 7 96 7 97 7 98 7 99 7 100 7 101 7 102 7 103 7 104 7 105 7 106 SHTM 2022 Part 1 Medical gas pipeline systems Vessel operating pressure The following operating pressures are required a main vessels 12 5 bar g b back up vessels 12 5 14 bar g Main vessel capacity The main vessel should normally be sized on the basis of 2 weeks supply This should be calculated as 14 x the average daily usage This should provide adequate storage and a cost effective vessel filling regime The gas supplier should however be consulted as there may be other factors such as geographical location space etc which need to be taken into account when sizing the main vessels Back up vessel capacity time that is it usage This will
19. nB 1 a Accident and emergency _ 40 Major treatment 40 QMT 40 T 1 radiodiagnostic special 4 procedures Version 2 0 June 2001 Page 47 of 264 Borders General Hospital NHS Trust on behalf of NHSScotland Property and Environment Forum 4 68 4 69 4 70 SHTM 2022 Part 1 Medical gas pipeline systems Table 11 Typical pressure and flow requirements for surgical tools Type of tool Pressure kPa Flow l min Small air drill 600 700 200 Medullary reaming machine 600 700 350 Oscillating bone saw 600 700 300 Universal drill 600 700 300 Craniotome 600 750 300 System capacity Unlike respirable equipment surgical tools are used intermittently typically for a short burst of a few seconds up to a maximum of 2 3 minutes The manifold or plant therefore should have the capagity to provide the design flow of the pipeline for a maximum period of 5 in any 15 minute period ut Table 12 Surgical air 700 kPa design and dwersie d flows Department Design flow for e Diversifiat low Q l min terminal unit l min T 1 350 4 Operating room 350 W 350 SDU ODA 350 workshop etc QWS 350 Terminal units ded ror equipment testing It may be provide surgical air at 700 kPa in the equipment service workaop for testing purposes Unless a surgical air 700 kPa ilable nearby it may be cost effective to use portable cylinders with a two stage regulator If a pipeline supply is to be provide
20. per workstation p project team option Version 2 0 June 2001 Page 28 of 264 Borders General Hospital NHS Trust on behalf of NHSScotland Property and Environment Forum 3 17 SHTM 2022 Part 1 Medical gas pipeline systems Scale of provision of terminal units Department O N O N O O MA4 SA7 VAC AGSS Out patient department Treatment room 1 1p i 1p 1 1p Sterile services department Washing room 1 i Packing room S 1 Medical equipment re assembly per work station 1 1 i 1 Medical equipment workroom per workstation 1 p project team option Note 1 Nitric oxide Terminal units for nitric oxide may be requ as oroject team option in intensive therapy units and neonatal units In excepti i nitric oxide may be required in ii 150 2 5 mm for two terminal units only This should be sufficient for double flow meters to be used for example between an oxygen terminal unit and a vacuum terminal unit serving two bed spaces b the distance between the centre of the terminal unit and a potential obstruction on either side for example when installed in a corner should be a minimum of 200 mm on either side NOTE Where in some ward areas terminal units are installed in recesses behind covers decorative panels etc allow an additional 100 mm on each side of the outermost terminal units and 200 mm from centre to top of recess and 300 mm from centre to bottom of rec
21. a green Normal indicator normal b yellow liquid low lt 25 re fill liquid c yellow liquid cylinders empty re fill liquid immediately standby in use d red pressure in standby system reserve low lt 50 e red pipeline pressure fault pressure fault Conditions b to e should be transmitted to the central alarm system Where relays are used they should be normally energised relays which de energise under fault conditions with contacts having a minimum rating of 50 V dc 50 mA Version 2 0 June 2001 Page 78 of 264 Borders General Hospital NHS Trust on behalf of NHSScotland Property and Environment Forum 6 87 6 88 6 89 6 90 6 91 6 92 6 93 SHTM 2022 Part 1 Medical gas pipeline systems Alternatively volt free normally closed contacts rated at 50 V dc 50 mA should be provided for transmission of conditions a to e to the alarm system The panel can be incorporated into the liquid cylinder manifold control unit or be a separate unit within the accommodation If mounted separately the cabling should be monitored for open short circuit In the event of sucha cabling fault a red system fault lamp should be illuminated on the alarm signal status unit together with the appropriate alarm condition Oxygen concentrator installations PSA plant General Oxygen concentrators or pressure swing adsorber PSA systems may be an alternative to the more trad
22. 4 43 Nitrous oxide oxygen mixtures 4 47 Medical air 4 47 General 4 49 Medical air 400 kPa 4 49 General 4 55 Pressure requirements 4 59 In patient accommodation 4 63 Surgical air 700 kPa 4 63 Flow and pressure requirem ts NM Pa surgical air system 4 66 Diversity 4 68 System capacity 4 69 Terminal units inten quipment testing 4 71 Vacuum 4 71 In patie 4 75 Operatifig depa 4 82 In iv etheragy unit coronary care unit and neonatal unit 5 Syste eneral page 51 5 1 Cyw ader maaifold installation s ral 5 9 Pressure control 5 14 YW Manifold monitoring and indicating system 5 16 Manifold control unit 5 17 Manifold monitoring 5 18 Manifold indication unit 5 19 Alarm signal status unit 5 23 Emergency reserve supply 5 23 General 5 31 Emergency reserve supplies for manifold installations 5 33 Emergency reserve supply for air compressors liquid oxygen oxygen concentrators PSA 5 34 Location Version 2 0 June 2001 Bae 4 Of 264 Borders General Hospital NHS Trust on behalf of NHSScotland Property and Environment Forum SHTM 2022 Part 1 Medical gas pipeline systems 5 35 Design 6 System design Oxygen supplies page 59 6 1 Bulk liquid oxygen systems and vacuum insulated evaporator VIE 6 1 General 6 5 System sizing 6 9 Equipment description 6 10 Standby oxygen facility 6 11 System layout 6 12 VIE 6 15 Control piping and instrumentation 6 17 Pressure raising system 6 19 Direct reading contents gauge
23. Appendix 4 Membrane filter test device page 240 Appendix 5 Equipment for contaminant testing page 242 Version2 0 June2001 ss sti OW SS Page 13 Of 264 Borders General Hospital NHS Trust on behalf of NHSScotland Property and Environment Forum SHTM 2022 Part 1 Medical gas pipeline systems Appendix 6 Equipment for gas identification page 243 Appendix 7 Procedures for measuring the design flow of vacuum plant page 245 Appendix 8 Procedure for measuring pipeline volume page 246 Appendix 9 Pressure loss data page 248 Appendix 10 Pressure regulation for 400 kPa medical gases and medical air and 700 kPa systems surgical air page 254 References page 257 Version 2 0 June 2001 Page 14 of 264 Borders General Hospital NHS Trust on behalf of NHSScotland Property and Environment Forum 1 1 1 2 1 3 1 4 1 5 1 6 1 7 1 8 1 9 SHTM 2022 Part 1 Medical gas pipeline systems 1 Scope Guidance in this document Guidance in this part of Scottish Health Technical Memorandum SHTM 2022 covers piped medical gases medical compressed air and medical vacuum installations and applies to all medical gas pipeline systems MGPS installed in healthcare premises An MGPS is installed to provide a safe convenient and cost effective system for the provision of medical gases to the clinical and nursing staff at the point of use It reduces the problems associated with the use of gas cylinders such a
24. Cross connection These tests should be arried of on one pipeline at a time All pipelines should be at atmo eri re and AVSUs should be open A single pressure sour Choy d be used and connected to one pipeline at a time which should reg naer pressure throughout the test Procedur The procedu is as follows a connect one pipeline to the pressure source at pipeline distribution pressure b in order to depressurise the other system insert an open probe into one terminal unit on each other system Check that no gas flows into or out of these probes c check that gas flows through every terminal unit of the pipeline under pressure d check that there is no gas flow from any other terminal units when they are opened with the correct probes Results Record the results on Form B6 if there are no cross connections Version 2 0 June 2001 Page 211 of 264 Borders General Hospital NHS Trust on behalf of NHSScotland Property and Environment Forum 15 173 15 174 15 175 15 176 15 177 15 178 SHTM 2022 Part 1 Medical gas pipeline systems Repeat the procedure described above on each pipeline in turn including vacuum preferably at one session This test should be repeated in full if any subsequent modifications are made to the pipeline system during construction Functional tests of terminal units These tests may be carried out at the same time as the cross connection test described
25. In either tools This may be derived fro case the terminal units w 700 kPa terminal units connector is already sp angeable screw thread NIST nitrogen and should be used The pressure nit should comprise a regulating valve with upstream and downstreanv Whatever Stem is installed the overall system should be designed to provide imum of 700 kPa at the front of each terminal unit at a flow of 350 l min The maximum pipeline distribution pressure under no flow or low flow conditions should not exceed 9 bar g Cylinders of medical air should always be available for use in an emergency Cylinder manifold supply systems These should generally be based on the systems described for medical air cylinder manifold systems in Chapter 5 except that the emergency reserve supply will not normally be required and the alarm system will be much simpler The alarm conditions should be transmitted to the central alarm system to alert porters and other staff of the need to change cylinders Version 2 0 June 2001 Page 112 of 264 Borders General Hospital NHS Trust on behalf of NHSScotland Property and Environment Forum 8 11 8 12 8 13 8 14 8 15 SHTM 2022 Part 1 Medical gas pipeline systems Compressor supply systems These should generally be based on the requirements for medical air 400 kPa systems given in Chapter 7 and the quality of the delivered surgical air should be the same as medical air
26. June 2001 10 53 10 54 System design Nitric oxide SHTM 2022 Part 1 Medical gas pipeline systems Duplex system Plant control indication page 140 Nitric oxide pipeline installations 11 1 11 5 11 10 11 14 11 22 11 24 11 28 11 29 11 30 11 32 11 38 Warning and alarm syste General Panel location 12 7 12 8 system d Introduction Design considerations Provision of terminal units valves and area valve service units AVSUs Manifold Provision of valves Provision of AVSUs Pipeline distribution Identification Alarm systems Nitric oxide risk assessme Validation and verification HH compliance page 146 Central indica Repeat Area warning ai alarm panel location nents Labelling Visual signals Audible signals Automatic re setting Temporary muting Continuous muting Electrical wiring System integrity Relay condition Mains power supply SELV FELV power supply Test facility Page 9 of 264 Borders General Hospital NHS Trust on behalf of NHSScotland Property and Environment Forum SHTM 2022 Part 1 Medical gas pipeline systems Warning and alarm system faults 12 31 General 12 32 Line fault 12 33 Communication wiring fault 12 34 Mains power failure 12 35 Standby battery 12 36 Legend 12 37 Indicator panel requirements for all systems 12 37 Indicators 12 40 Labelling 12 41 Construction 12 48 Remote audible sounder 12 49 Central indicator pan
27. June 2001 Page 230 of 264 Borders General Hospital NHS Trust on behalf of NHSScotland Property and Environment Forum SHTM 2022 Part 1 Medical gas pipeline systems Medical Gas Pipeline Total System Tests Form B11 Sheet of Sheets Hospital Scheme File Number Date Warning Systems This is to certify that WARNING SYSTEMS on the following medical gas pipeline systems have been tested in accordance with paragraphs 15 76 15 77 as follows System VAC Specified Warning Pressure Observed Warning Pressure Warning Given o ee ee Return to normal a ee y Marking Hp y Y All Functions on all stations a VV an Stand by Power Contractor s Represe Status Date Contract Superv Status Date Witnessed on behalf of By Status Signed Date Version 2 0 June 2001 Page 231 of 264 Borders General Hospital NHS Trust on behalf of NHSScotland Property and Environment Forum SHTM 2022 Part 1 Medical gas pipeline systems Medical Gas Pipeline Total System Tests Form B12 Sheet of Sheets Hospital Scheme File Number Date Verification of Drawings This is to certify that in accordance with paragraphs 15 78 the as fitted drawings of the following systems record all variations from the contract drawings Contract Contractor s Supervising Drawing Representative Officer System Status Name Status Name O2 NO
28. SHTM 2022 Part 1 Medical gas pipeline systems Repeater indicator panel location Repeater panels include an audible facility and should be provided for a central system to display information which is essential for the continuing operation of the system Area warning and alarm panel location Local systems to display high and low gas pressure in the area should be installed downstream of the AVSU The sensors for these systems should be located downstream of designated AVSUs It should not be possible to isolate the sensor with a separate shut off valve The panel appropriately labelled should be located at a nurses station within each department and in special departments SCBU ITU and A amp E Some warning system information may be appropriate in the pharmacy department particularly in the case of pressure swing adsorber PSA plant synthetic air plant and compressed air systems 4 NOTE Sensors may be fitted within the AVS Mosu Version 2 0 June 2001 Page 147 of 264 Borders General Hospital NHS Trust on behalf of NHSScotland Property and Environment Forum V D D D Eo Q Q V v D F 2 E R L N S A T Y Figure 16 Typical warning and alarm system layout reproduced by kind permission of Shire Controls W S S UUM Jue W S YUM pjojiuey ATA usbAxEQ JO IWSUECI S IUSUOGWIOO Sul JO pu4
29. Status Signed Date Name All appropriate tests satisfactorily carried out System may now be taken into use Authorised Person MGPS Status Signed Date Name Version 2 0 June 2001 Page 219 of 264 Borders General Hospital NHS Trust on behalf of NHSScotland Property and Environment Forum SHTM 2022 Part 1 Medical gas pipeline systems Medical Gas Pipeline Carcass Tests Form B1 Sheet of Sheets Hospital Scheme File Number Date Part 1 Leakage Test Labelling and Marking Sleeving and Supports This is to certify that a LEAKAGE test in accordance with paragraphs 15 39 15 42 was carried out on the piped system on this scheme and that during the test a pressure as shown in column 2 below was held as follows A certified gauge number was used Section Test Hours Pressure Pressure Pass Fail Labelling Sleeving Tested 1 Pressure on Test Drop Drop Specification amp Marking and Supports 2 3 kPa hr 0 025 as para as para 4 5 6 15 37 15 38 Yes No Yes No 8 Part 2 Link Betweg n For the purpose of c ns oe test the following links have been made This is to certif ind the above tests have been carried out and that the following links have been removed Contractor s representative Status Signed Date Name Contract Supervising Officer Status Signed Date Name Version 2 0 June 2001 Page 220 of 264 Borders General Hospital NHS Trust on behalf of NHSScotl
30. 13 75 General N 13 79 Labelling 13 81 Pressure sens page 176 onstruction of plantrooms Location of plantrooms Access Construction and layout of manifold rooms Heating and ventilation of plantrooms Lighting Noise control Validation and verification General Summary of tests 15 14 Tests and checks on the pipeline carcass 15 15 Teston the pipeline system 15 16 Tests before use page 180 Page 11 of 264 Borders General Hospital NHS Trust on behalf of NHSScotland Property and Environment Forum 19 37 15 44 15 79 15 86 15 88 15 106 15 111 15 115 15 116 15 117 Version 2 0 June 2001 15 17 SHTM 2022 Part 1 Medical gas pipeline systems General requirements for testing 15 17 General 19 29 Modifications extensions or repairs to existing systems Requirements for pipeline carcass tests 15 37 15 38 15 39 Labelling and marking Sleeving and supports Leakage 15 43 Cross connection Requirements for pipeline system tests 15 44 15 49 15 50 15 54 15 58 15 63 15 64 15 65 15 66 15 68 15 72 15 74 15 76 15 78 Filling with me Purging Quailit 15 1 Leakage from total compressed medical gas systems Leakage into total vacuum systems Closure of area valve service units Zoning of AVSUs and terminal unit identification Cross connection Flow and pressure drop at term Mechanical function of termi Gas specificity of terminal u NIST connectors Performance tests o Fu
31. 15 requires a minimum plant manifold pressure of approximately 1150 kPa The line pressure regulator has a control range of 5 the maximum pressure likely to occur during static conditions is therefore approximately 1265 kPa These pressures are approximate in practice the exact settings will depend on the design of the supply system and the distribution system It is important to achieve the required flow at the minimum pressure at the point of use the actual pressure settings which are used to achieve this will vary with each system design Area alarm nominal setting The following statements apply to both 400 kP 0 kPa systems lt should be noted that the alarm pressure s valve settings overlap It is not intende provide a warning of safety valve reli to provide users with advance war line pressure which could adversely as blenders Safety valves ar nt event of regulator failure system should oressure alarm is intended a potentially hazardous increase in e operation of equipment such provide system protection in the hould allow the alarm to switch off ata static pressure in the system settin i The over pressure alar pressure just abo Safety valves t minimum i pressure ve a specified performance in which the is 97 of the set pressure whilst the full discharge e safety valve set pressure Air receiver Set pressure is 110 of the nominal working pressure Version 2 0 June 2001 Page
32. 3 kPa 760 mmHg To the back of the local regulator o Existing compressed aif syste have been designed to provide 250 min at the terminal un acco Jance with HTM 22 1978 It may not be ide 350 litres l min as specified in Table 4 be circumstances where this would be acceptable lt may be ne essary to repeat some of the system performance tests such as flow and pressure drop at selected terminal units on the completed system to demonstrate satisfactory performance see paragraph 15 33 The break in to the existing system should be carried out with an inert gas shield where practical and a physical break must always be made between the existing in use system A leak test must be carried out using a suitable leak detection fluid on this joint at working pressure and the joint purged with the working gas Fluxless brazing should of course be used Danger do not use labels should be affixed to outlets taken out of service in areas occupied by patients Version 2 0 June 2001 Page 188 of 264 Borders General Hospital NHS Trust on behalf of NHSScotland Property and Environment Forum 19 37 15 38 15 39 15 40 15 41 15 42 15 43 SHTM 2022 Part 1 Medical gas pipeline systems Requirements for pipeline carcass tests Labelling and marking A visual check must be made on each pipeline system to ensure that the pipelines are labelled in accordance with the contract specification and that the
33. 34 7 39 SHTM 2022 Part 1 Medical gas pipeline systems There are a number of methods for measuring particle size and concentration such as cascade impactors particle counters light dispersion photometers laser counters etc None of these is suitable for sampling from a compressed air pipeline Filters are specified in terms of performance tests for example sodium flame test DOP test etc Water Water is always a contaminant in a compressed air system regardless of the type and location of the compressor plant since the air drawn into the compressor intake is never completely free of water vapour The amount can vary from 2 5g m to over 40g m depending on the climatic conditions some of this is removed by the after cooler and receiver but about 20 g m is likely to remain in the compressed air unless removed by dryers can only perform satisfactorily down t and are therefore not recommended e dewpoint of about 3 C orm of drying Oil With oil lubricated compr is inevitable that the compressed air contains oil Even with ssors non lubricated a freedom from oil and oi is unlikely to ceed 0 5 mg m The amount of oil present as bulk liquid and aerosol present in a compressed air system is more difficult to predict With modern well maintained oil lubricated compressors it is unlikely to exceed 5 mg m due to the high efficiency oil air separator Oil contaminated compressor condensate
34. 54 3 0 2 7 76 3 6 3 0 Pipelines need not be laid with falls In the case acuum the sub atmospheric pressure will result in the evapor ny moisture entering the system It is possible however for vacu flow and thus for systems to require flushing through nits into the main unit ine to avoid flooding other vertical in riser should be provided with inage when the system is under e lockable in the closed position No ts are required The connection from individual vacu should be taken from the top of t I pipe drops during flushing Each va a double valve arrangement vacuum one of the valve other sloping or draina arran in certain circumstances as follows Pipelines need fu cti a where pipe with sleeves h walls partitions or floors they should be fitted opper pipes which conform to BS EN 1057 and be priate wall or ceiling plates b in radio nostic procedure rooms etc radio frequency RF screening by meanSjof extended sleeves will be necessary The advice of the equipment manufacturer should be sought c corrosion of pipes can occur where they are in contact with timber treated with fire resistant or flame retardant compounds for example some timber used for roof trusses and floor joists This contact should be avoided by the use of impermeable non metallic materials in the area where contact may occur PVC spacers or adhesive PVC tape may be used for this purpose If spacers are used the
35. 63 13 64 13 65 13 66 SHTM 2022 Part 1 Medical gas pipeline systems The fittings should be provided with adequate venting to allow escape of gas in the event of rupture of one or all of the medical gas services The recommended height for rigid pendants is 2000 mm above finished floor level FFL The use of medical air for pneumatically actuated pendants is covered in Chapter 4 The manufacturer should confirm that these requirements are met prior to the installation of the equipment this should be demonstrated during the validation and verification procedures Flexible pendant fitting These should comply with the requirements of BS 5682 as amended In particular all loose assemblies should be provid ith appropriate NIST connectors Bed head trunking walling system with SHTM 2015 Bedhead ided for electrical services These fittings should generally be in services Separate compartments nurse call radio etc and medical ga be p Flexible connecting asse 5682 as amended ed within the fitting should comply with BS The medical gas cagao ent gould be provided with ventilation by means of louvres slots etc ti he accumulation of any gas in the event of rupture of the ry aepipeline services it is becoming fashionable to install medical gas aled recesses or behind decorative panels paintings etc to engeN Jer a more domestic appearance In such cases adequate provision muS gt b
36. AGSS Maximum pressure av inlet 30 l min continuous fla aximum pressure at inlet at 90 I min continuous flow Positive pressure relief at inlet 50 Pa T 500 Pa to transfer system Maximum amp ssUMiNCrease Maximum pressure increase at Qet a80 Mjn for 5 s at inlet at 90 l min for 5 s With any hose or tubing totall Pa 2 kPa obstructed Maximum induced flow to th keceiving system from the transfer system J 0 5 l min v Experienc thet any sub atmospheric pressure at the patient end of the AGSS e a gas flow from the breathing system under certain conditions ilst this does not result in any barotrauma there have been instances wh re insufficient gas has been available to the patient as a result of this phenomenon Therefore there is a requirement in the British Standard that the induced flow from the patient s breathing system should not exceed 0 5 l min Performance criteria An AGSS which complies with BS EN 737 BS EN 740 is intended to remove all gases delivered to the receiving system within the performance and safety criteria specified There should be no spillage of nitrous oxide from the receiving system when the AGSS is set up as specified in the British standard This test is intended to be carried out by the manufacturer It is not easy to reproduce the specified challenge waveform in an operating department It should not be necessary to carry out this test on site as no spillage should occur
37. Borders General Hospital NHS Trust on behalf of NHSScotland Property and Environment Forum 13 34 13 35 13 36 13 37 13 38 SHTM 2022 Part 1 Medical gas pipeline systems Control of cylinders The contractor and the site engineer must keep a record of nitrogen cylinders held on a site Nitrogen cylinders should be accounted for and removed from the site at the end of the contract and must not become mixed up with medical gas cylinders Other installation processes Oxygen free nitrogen should also be used internally on pipework as in paragraph 13 31 whenever annealing or hot forming of pipework is carried out Inspection of joints Joints brazed should be inspected in accordance with the following procedure a before pressure testing the site engine fittings to be cut out for examination in o the finished joint The exact numb of the installation but as a guid installations should be cut out normally more than five fittings event a minimum of two and not e cut out for examination b the fittings cut out should examined If unacce cut out until the ext The joints should b 13 38 c the pipelin d the pi quartered longitudinally and are found adjacent fittings should be ty workmanship has been established in accordance with paragraphs 13 37 and j t of ana f SSESS ade good Oul fully inserted up to the shoulder of the fitting The tube and
38. Gases Association Medical gas pipe systems Design and BSI Dept installation of QAS 3720 1 206 of Health Guidance notes for users of liquid BOC Gas cylinders of low pressure cryogenic liquid supply vessels for liquid oxygen nitrogen or argon with capacity of under 450 litres G4521 Home Office Fire Prevention Guide No 4 Safe use and storage of liquefied petroleum gas in residential premises Version 2 0 June 2001 Page 263 of 264 Borders General Hospital NHS Trust on behalf of NHSScotland Property and Environment Forum SHTM 2022 Part 1 Medical gas pipeline systems BDA Advice sheet A3 health and safety law for dental practice EL 96 33 Occupational exposure standards for Dept of anaesthetic agents Health EH49 96 Occupational exposure limits HSE Version 2 0 June 2001 Page 264 of 264 Borders General Hospital NHS Trust on behalf of NHSScotland Property and Environment Forum
39. Hospital NHS Trust on behalf of NHSScotland Property and Environment Forum 11 31 11 32 11 33 11 34 11 35 11 36 11 37 SHTM 2022 Part 1 Medical gas pipeline systems The alarm system should comply fully with the appropriate requirements for manifold alarms and as follows Condition Legend Colour Audible a duty bank empty change cylinder yellow yes change over to standby bank b standby bank below 50 change cylinder yellow yes Capacity immediately c Purge cylinder change cylinder yellow yes pressure below 10 immediately d pipeline pressure pressure fault red yes below 80 This action will be necessary before changing working gas cylinder Concerns about the effects of exposure to documented and have lead to the develoom departments AGSS is not a practical rol assessment ventilation is considere thoa and based on a risk isfactory alternative The quoted occupational exposure Mai nitric oxide are 25 ppm over an 8 hour time weighted averag or 15 minutes and for nitrogen dioxide are 3 ppm over a ime weighted average and 5 ppm for 15 minutes Therapeutic conc ric oxide are extremely low below current The conversion to higher oxides of nitrogen ation dependent is unlikely to result in e limits being exceeded at with no scavenging but ventilation providing 12 air changes per aour the highest levels recorded were in the vicinity of the ventilator outl amp t and were
40. NHS Trust on behalf of NHSScotland Property and Environment Forum 15 179 15 180 15 181 15 182 15 183 SHTM 2022 Part 1 Medical gas pipeline systems Procedure The procedure is as follows a insert leaks into selected terminal units AVSUs and NISTs as appropriate throughout the system under test to provide a total flow equal to the total design flow of that system b runthe system so that the pressure vacuum at the source meets the specification given in column 6 of Table 23 c check the gauge pressure at the specified flow Table 4 at selected terminal units throughout the system d record the results on Form B8 if they are in accordance with paragraph 15 68 NOTE Remedial work may be needed if these specifications are not met Supply system tests General dc All supply systems should be installe cted to normal and standby power supplies Procedure The procedure is as fol a the functions arameters of each item of plant should be checked b the supply s ms snould be shown to operate on the essential power suppl c all pipe joifts should be tested for leakage at normal operating pressur d the compressor plant should be tested for leaks during normal running Results lt should be confirmed that the manufacturer s specification meets the requirements of the contract specification Record the results on Form B9 if they are in accordance with the specific checklist V
41. They must be individually capped at both ends and delivered to site identified as medical gas pipes NOTE Pipes should only be cut with wheel pipe cutters not hacksaws to prevent the ingress of particulate matter Pipe jointing fittings All pipe jointing fittings and sub assemblies of fittings for connection to pipes must be cleaned and degreased for oxygen service and be free of frequently installed by the contractor si pipelines Degreased pipe and fittin vacuum installations to avoid conf vacuum and anaesthetic gas scave used for larger systems pipework may also be used for tems AGSS and is generally Pipeline jointing General COpper to copper joints only will be permitted azing filler rods which can be used without flux and in free nitrogen which will be blown through the razing procedure to prevent the formation of oxides should not be used as the inert gas shield This method eliminates the formation of oxide within the pipe leaving a clean bore Some slight burnishing may occasionally be observed on sectioned joints Purging is still required to remove the internal shield gas and the other particulate matter not associated with the brazing operation Copper joints to brass or gunmetal fittings will require the use of flux with subsequent cleaning to remove the flux residues and oxide deposits Heating of the joint for brazing should be carried out with oxygen acetylene or acetylene hydrogen liq
42. This may be appropriate on some sites A risk assessment should be carried out to establish the vulnerability of the main supply system of both oxygen and nitrogen 7 129 An emergency supply facility may be either a amedical air compressed gas manifold located away from the main supply within the hospital b portable emergency manifolds on trolleys Version 2 0 June 2001 Page 111 of 264 Borders General Hospital NHS Trust on behalf of NHSScotland Property and Environment Forum 8 1 8 2 8 3 8 4 8 5 8 6 8 8 8 8 9 8 10 SHTM 2022 Part 1 Medical gas pipeline systems 8 System design surgical air 700 kPa General Surgical air at 700 kPa is only used as the power source for surgical tools These tools typically require high flows up to 350 l min at 700 kPa at the point of use Where nitrogen is available on site it may be used as an alternative source of supply Supply systems for surgical compressed air may be a cylinder manifold system a dedicated 700 kPa compressor system or a compressor system capable of supplying both the 700 kPa and the 400 kPa supplies In practice the decision about which compressor system to install needs careful consideration due to the flow rates requi and total usage complexes specialising in orthopaedic necessitating a high use of pneumati the power source for surgical It is possible to use nitrogen instea iquid source or cylinders
43. a plantroom If mounted separately the cabling should be monitored for open short circuit In the event of such a cabling fault a red system fault lamp should be illuminated on the alarm system status unit together with the appropriate alarm condition Version 2 0 June 2001 Page 127 of 264 Borders General Hospital NHS Trust on behalf of NHSScotland Property and Environment Forum 9 62 9 63 SHTM 2022 Part 1 Medical gas pipeline systems Plant management Connections should be provided which allow monitoring but not control of plant alarm conditions b to e and pump running for each vacuum pump These connections should be volt free contacts normally closed for each condition having a minimum rating of 50 V dc 50 mA Plant should be operated in accordance with the manufacturer s instructions and be covered by a sound effective planned preventative maintenance PPM policy Version 2 0 June 2001 Page 128 of 264 Borders General Hospital NHS Trust on behalf of NHSScotland Property and Environment Forum 10 1 10 2 10 3 10 4 10 5 10 6 SHTM 2022 Part 1 Medical gas pipeline systems 10 System design anaesthetic gas scavenging systems General Anaesthetic gases are considered to be substances hazardous to health for the purposes of the Control of Substances Hazardous to Health Regulations 1999 COSHH except where they are administered to a patient in the course of medical tr
44. a top gas economiser connection IT IS NOT RECOMMENDED THAT ANY OF THE VALVES ARE OPENED OR CLOSED EXCEPT BY THE GAS SUPPLIER S PERSONNEL OR EXCEPT IN AN EMERGENCY BY AUTHORISED PERSONNEL NOTE The valve information applies to BOC VIEs only If other manufacturers installations are in use the operating procedures should be ascertained by the authorised person MGPS for the site Pressure raising system The pressure of the VIE is automatically contro d b regulator which controls the flow of liquid to required The vaporised liquid maintains the minimum of 10 5 bar g pressure raising uregaising vaporiser as smice pressure ata e ere uld be automatic control of O individual vaporiser d teremetry systems Where several vaporisers are install changeover to prevent excessive ic Direct reading contents e differential pressure type indicating the liquid content es required for use with differential A telemetry syst be installed which continuously monitors and ants and tank pressure This information can be used operating covdition to assist maintenance requirements This data will be transmitted to both the hospital and the gas supplier as required Telemetry systems data can be used to predict the consumption rates and future demands Safety note VIEs are strictly designed and manufactured to recognised national international codes Associated equipment is designed to the a
45. and it may istration because of the The supply system for compressor system or emergency reservess ning system synthetic air and includes an mpressor plant should always be specified use up to 80 7min free air continuously The exact flow requirements will depend on thdesign of the ventilator The flow and pressure requirements for some typical ventilators are given in Table 9 Current models of anaesthetic ventilators are very similar to intensive therapy models and may require peak flows of up to 80 I min and average flows of 20 I min Almost all such units are pneumatically driven and electronically controlled Medical air 400 kPa is also used for other equipment such as anaesthetic gas mixers humidifiers and nebulisers The flow rates normally required would not exceed 10 l min and this flow is always in excess of the actual volume respired Version 2 0 June 2001 Page 44 of 264 Borders General Hospital NHS Trust on behalf of NHSScotland Property and Environment Forum SHTM 2022 Part 1 Medical gas pipeline systems Pressure requirements 4 55 The minimum pressure required at terminal units for respiratory use is 355 kPa and all terminal units should be tested to ensure that the pressure does not fall below 355 kPa at flows of 80 I min in intensive therapy units and coronary care units 40 l min in special care baby units and operating suites 20 min in ward areas Table 9 Typical pressure and flow requi
46. as specified in paragraph 2 10 lt is not necessary to provide duplex systems since surgical air is not used for life support systems It may however be considered appropriate to provide a simple standby manifold for larger installations To avoid confusion with the emergency reserve cylinders supplies for 400 kPa systems the surgical air standby system for 700 kPa systems where provided is referred to as a back up system Operating and alarm system cylinder manifold supply system Manifold monitoring and indicator system The monitoring and indicator system should ferfome the following functions a overall manifold monitoring b manifold condition indication c overall supply plant indication All functions should be priate identified Manifold monitori The manifold Onitored to detect the following a duty operating b duty b and standby operating c standby Wank below 10 capacity when duty bank is empty Manifold indicator unit There should be indicators to show the following conditions a green running indicator b a yellow empty indicator for each bank when the running bank is empty and the reserve is in use c a yellow low pressure indicator for each bank when changeover has occurred and the pre set low pressure has been reached NOTE Conditions b and c are the same Version 2 0 June 2001 Page 113 of 264 Borders General Hospital NHS Trust on beha
47. based on Table 4 the volume flow is expressed in terms of free air flow Qa and it is therefore not necessary to calculate Qg The flows required at terminal units as shown i for each terminal unit the actual pipeline distri the diversified flow rates derived using the following paragraphs able 4 are design flows Pipeline flows Normally because Pg is considere beonstant throughout the entire pipeline network the volume ired in the upstream branch of a T junction is simply the s volume flows in the downstream branches flows in this way the resultant total flow is e and would result in unnecessarily large For vacuum systems the minimum vacuum should not fall below 300 mm Hg at each terminal unit at a flow of 40 l min The design of the pipework system is based on flows and acceptable pressure loss as shown in Table 4 to include terminal unit pressure loss given in Table 23 Chapter 15 The overall consumption may be lower in practice but the systems would be capable of meeting the calculated demand within an acceptable range that is the design flow operating at a nominal pressure of 400 kPa Departments usually comprise several ward units and treatment rooms In order to avoid confusion departments should be defined at the project design stage so that diversified flows may be calculated Version 2 0 June 2001 Page 37 of 264 Borders General Hospital NHS Trust on behalf of NHSScotland Property a
48. behalf of NHSScotland Property and Environment Forum 4 32 4 33 4 34 4 35 4 36 4 37 4 38 4 39 4 40 4 41 SHTM 2022 Part 1 Medical gas pipeline systems Intensive therapy and coronary care units The diversified flow for these units assumes that all bed spaces may be occupied Each terminal should be capable of delivering 10 l min and the diversified flow is calculated assuming 10 l min for the first bed space and 6 I min for each of the remainder Bed spaces are used instead of numbers of terminal units to calculate the diversified flow since each bed space may have up to four or more terminal units associated with it Oxygen should not be used as the driving gas for gas powered ventilators if they are capable of being powered by medical air The minimum flow characteristic which has proved adequate to drive current types of ventilator is 80 I min at 355 kPa If oxygen has to be used to power ventilators anggor ventilators are operating Maternity For all normal delivery suites first terminal unit and 6 1 p9 remainder In this case terminal units are provided for both m ther an y and therefore the number of in the same ways SOperating room The abnormal delivery suite should be d in the same way as the operating department The maternity operating suite should be considered in the same way as operating departments Nitrous oxide Nitrous oxide is provided mainly for anaesthetic
49. continuously for low loads The reservoir should be manufactured in accordance with BS 5169 for class Ill with test certificates provided to the user The minimum test pressure should be 4 bar g The water capacity of the reservoir should be equal to the plant design flow at 450 mm Hg 60 kPa in terms of free air aspirated in 1 minute with the pump operating at 450 mm Hg 60 kPa Provision should be made for draining the reservoir under vacuum conditions By pass facilities should be provided so that the reservoir can be drained and inspected without interruption to the vacuum supply The reservoir should be fitted with suitable lifting lugs and feet If multiple reservoirs are provided they should be arranged in parallel The bacteria filters and drainage trap should com rise two identical sub sub assembly to be on stream Each sub a bacteria filter rated at the plant capacity with a description of a safe proce filters and emptying the drainage tr The drain with a tran y be integral with the bacteria filter and should be fitted nt Sterilizable bowl to collect liquid Microbial contamination whereas there is no firm evidence which has demonstrated the need for bacteria filters it is recommended that such devices are included as precautionary measures NOTE Precautions for changing filters are included in the Operational management part 2 of this SHTM Version 2 0 June 2001 Page 123 of 264
50. desiccant type are usually integrated within the molecular sieves and therefore do not regenerate independently Refrigerant dryers may also be included Oxygen monitoring system The plant should include a calibrated paramagnetic oxygen monitoring system comprising oxygen analyser oxygen concentration indicator oxygen flow monitor and oxygen concentration flow recorder Connections for calibration cylinders should also be provided In the event of the concentration falling below 94 the monitoring system should isolate the PSA system from the pipeline distribution system so that the emergency reserve manifold goes into operation In addition to the above an independent monitoring system should be provided to isolate the plant when the concentration falls below 94 The segund system need not be provided with a flow indicator or recorder Operating and indicating system The operating and indicating system as appropriate OU rm the following functions a overall plant control and i b individual compress rtin c individual vacuum pump sta ing where fitted d control of dr lled as separate component e control of f plant itoring and indication g option n of the plant alarm status this function may be consider d to be part of the alarm system Provided that the individual compressor starters are housed in a separate compartment these functions may be carried out by separate units or may be installe
51. et E a Pan _ oe E on sz a fore z sat lt ee Se E3 T os Es Ex Ea UOlJO9UUODI9 U O Jopuow UuabAxO gt lt gt lt Q AJEA HO INYS p JOWUOW Jossaidwoy uabAxo J ulesq x Q p pnjou 4 eiiandej Ieuondo apa E ya U w s s uly K gt lt lt yoss dwoo f DAK Ks 6 d gt lt M Aiddns m s 19Al999H 191S00 dB NIS OW JOA990Y mu uy 194l 4 q 40 98UU09 1 l 4 q x 4 2 ho abneb ainssdid a i Aid as AJLA J l 1 INSS ld Aud ae a LL Aud Aud N jeuoldo yiom odid jeuoldgQ J9 009 JOUY BDIAVP DAVIS Jejnoajow Ajddns Aiewld waj sAs are Ajddns Aiewlidg Borders General Hospital NHS Trust on behalf of NHSScotland Property and Environment Forum Version 2 0 June 2001 6 98 6 99 6 100 6 101 6 102 6 103 6 104 SHTM 2022 Part 1 Medical gas pipeline systems Plant configuration The plant should comprise a duplex compressor if more than two compressors are installed the plant should provide the design flow with one compressor out of service b duplexed air treatment molecular sieve devices that is two sets of filters and a pair of molecular sieves one adsorbing whilst the other regenerates and one vacuum pump if required by the manufacturer All duplexed components should be capable of independent operation Compressors and vacuum pumps The compressors for the PSA systems may be any of the ty
52. in the event of a leak and during purging after cylinder changing The manifold should be semi automatic complying with the requirements for medical gas manifolds in this SHTM Additionally the manifold should have a nitrogen purging facility to purge any air introduced during cylinder changeover ongzach tailpipe The purging working gas before the manifold is made re the nitrogen supply used for purging needs t ow the minimum operating pressure of the manifold to pply of nitrogen to the patient and to prevent overriding of t tem The manifold operating pressure should be set to 4 2 bar g as recommended for other medical gases The nitrogen purging system should be set to operate at 2 bar g such that the warning system will continue to alarm if the service gas cylinder valves are not opened after cylinder charging Version 2 0 June 2001 Page 142 of 264 Borders General Hospital NHS Trust on behalf of NHSScotland Property and Environment Forum 11 22 11 23 11 24 11 25 11 26 11 27 11 28 11 29 11 30 SHTM 2022 Part 1 Medical gas pipeline systems Provision of valves Where nitric oxide systems are installed within or close to the department served the control of the distribution system will be by AVSUs and valves installed as part of the manifold system Where nitric oxide manifolds are remotely located AVSUs will need to be installed within the ward area Provision of AVSUs AVSUs sh
53. indicating system with alarms is also required Appropriate layout and adequate siting of these components should be provided Packaged supply systems are available from manufacturers which should be specified to meet the requirements given in this memorandum The plant should consist of at least two identical pumps a vacuum reservoir with by pass facilities two duplex bacteria filters with drainage traps appropriate non return valves isolating valves gauges and pressure switches an operating and indicating system an exhaust system and a test point Version 2 0 June 2001 Page 118 of 264 Borders General Hospital NHS Trust on behalf of NHSScotland Property and Environment Forum 9 9 9 10 SHTM 2022 Part 1 Medical gas pipeline systems th gt ND eyy S i t i The plant should have all round access for maintenance purposes and allowances should be made for changing major components The siting of the plant should allow for adequate flows of air to cool the pumps The manufacturers should be consulted over the range of operating temperature for which the supply system is designed In extreme cases refrigerator cooling may be required Version 2 0 June 2001 Page 119 of 264 Borders General Hospital NHS Trust on behalf of NHSScotland Property and Environment Forum SHTM 2022 Part 1 Medical gas pipeline systems Figure 13 Schematic diagram of a typical medical vacuum system reproduced by kind permis
54. is classified as a trade effluent by virtue of section 14 of the Public Health and the Public Health Scotland Act 1897 drainage of trade premises Act 1937 An oil condensate separator should therefore be installed Under the Water Resources Act 1991 section 85 it is illegal to make a discharge of trade effluent to controlled waters via a surface water drain without the consent of the Scottish Environment Protection Agency Version 2 0 June 2001 Page 94 of 264 Borders General Hospital NHS Trust on behalf of NHSScotland Property and Environment Forum 7 36 7 3 7 38 7 39 7 40 7 41 7 42 7 43 7 44 SHTM 2022 Part 1 Medical gas pipeline systems NOTE The maximum limits of oil in water are from 5 mg l up to 15 mg l Similarly under the Water Industry Act 1991 Regional Water Authorities enforce the limit of oil condensate discharged into the public foul sewer Prior consent to discharge is mandatory NOTE Maximum limits range from region to region from 25 mg l up to 500 mg l the Local Water Authority should be consulted Condensate from oil free compressors may be discharged to drain Any condensate produced from the compressor dryer system must be regarded as trade effluent and is therefore not suitable for discharge to any surface water system draining to any surface water sewer water course or soak away this may not apply if a suitable separatgr is installed Dryer co
55. least 25 mm should be maintained between each service and 150 mm should be the separation distance between medical gas pipeline and heating hot water service and steam pipelines Where pipelines cross over other services and a clearance of 25 mm cannot be maintained they should be electrically bonded and wrap insulated in accordance with IEE regulations They should be bonded to main earth at building entry and exit Buried pipelines should be run in a trench not less than 450 mm x 450 mm with the pipe protected throughout its length by a continuous glazed earthenware pipe or carried in properly drained ducts with removable covers These glazed pipes or ducts should be further protected where the pipe Version 2 0 June 2001 Page 161 of 264 Borders General Hospital NHS Trust on behalf of NHSScotland Property and Environment Forum 13 8 13 9 13 10 13 11 13 12 13 13 13 14 SHTM 2022 Part 1 Medical gas pipeline systems crosses areas used by wheeled traffic in such areas the glazed pipes and ducts should be encased in concrete Multi way ducts should be used where more than one pipe is to be carried The route of the pipeline should be identified on the surface and should be clearly shown on site layout drawings Pipelines concealed within walls and floors should have their route clearly shown on as fitted drawings Pipelines should not be encapsulated in floors and any joints should be kept to the minimum
56. least two oxygen two MA 4 bar and two vacuum terminal units for each bed space 11 11 To ensure maximum flexibility it is similarly recommended that two nitric oxide terminal units are installed for each bed space 11 12 The provision of nitric oxide has also been suggested for installation in specialist operating departments A clinical judgement will have to be made on such provision taking into account the additional complexity and consequences of discontinuation of the supply during patient transfer 11 13 BS 5682 does not include a terminal unit for nitric oxide In the absence of standards the dimensions given in paragraphs 3 18 3 20 are recommended they are based on the figures and tables in BS 5682 1998 Version 2 0 June 2001 Page 141 of 264 Borders General Hospital NHS Trust on behalf of NHSScotland Property and Environment Forum 11 14 11 15 11 16 11 17 11 18 11 19 11 20 11 21 SHTM 2022 Part 1 Medical gas pipeline systems y Py me Nd pyvino M i f I d The manifold should be located near to the areas to be served in secure accommodation and provided with good ventilation to the outside The accommodation should comply with the general requirements in this SHTM and have good access for cylinder handling In existing premises it may not be practicable to provide an external manifold room In such cases mechanical ventilation will be necessary to prevent the accumulation of gas
57. levels at least 2 hours running Odour threshold for particulate material is approximately 0 3 mg m The current moisture specification for oxygen is 60 vom the proposed Ph Eur for O air and N20 is 50 vpm Testing on site cannot be as accurate as testing under manufacturing conditions Oil A representative sample of all terminal units on medical compressed air systems and oxygen concentrator systems supplied by compressor plant must be checked to ensure freedom from odour or oil The most distant terminal unit on the index pipe run and plant test point must be tested for the total oil content Oil may be present as liquid aerosol or vapour and an appropriate test device is described in Appendix 2 The total oil content should be in accordance with Table 24 This test must also be carried out at a test point on the compressor system and oxygen concentrator system It is desirable to carry out this test at a plant test point Version 2 0 June 2001 Borders General Hospital NHS Trust on behalf of NHSScotland Property and Environment Forum Page 200 of 264 15 99 15 100 15 101 15 102 15 102 SHTM 2022 Part 1 Medical gas pipeline systems before any pipeline system is supplied by that plant to prevent contamination of the pipeline distribution system Care should be taken in selecting the test point to ensure a representative sample NOTE The compressor plant must only be used to supply medical air systems a
58. liquid oxygen installations i check that the heater unit where fitted vapouriser pressure controls relief valves pressure controls and warning devices operate according to specification ii check the function of the changeover to the reserve manifold iii check that operation is at maximum specified flow iv check the operation of the warning and alarm system and the plant indicator unit c compressed air plants i check for the correct rotation and current at full load ii check for excessive vibration and noise Version 2 0 June 2001 Page 194 of 264 Borders General Hospital NHS Trust on behalf of NHSScotland Property and Environment Forum d SHTM 2022 Part 1 Medical gas pipeline systems iii check all automatic operations iv check the changeover to reserve manifold v check the function of automatic drains and by pass valves vi check the operation of all plant at its maximum continuous rating vii check that the power consumption of the compressed air plant is in accordance with the contract specification viii check the accuracy of all pressure gauges and thermometers ix check that the insulation resistance and effectiveness of earthing of all electrical items are in accordance with IEE regulations extant edition x check that all plant operates with start up in the correct sequence when switched to the standby power source xi check that the positi
59. one base block on all other pipelines should be fully open Procedure at no gas flows from nder pressure pened checked for Connect one pipeline to the pressure source the open base block on the other pipelines vehi Each terminal unit on the pipeline under test flow and then reblanked When testin completed on one pipeline the pressure source should be remo pipeline should be left open to atmosphere Another pipette uld then be pressurised and the procedure repeated Results The contractor should ricord the satisfactory tests have been completed on Form B2 Leakage from medical gas systems ibed above should have been completed inal unit valves and other devices such as safety valves ensors should be fitted The supply system should be isolated from the pipeline there should be no links between the pipeline systems The test may be carried out on sections of each pipeline provided no section is omitted Different sections and pipelines may be tested at the same time Procedure Connect a suitable pressure measuring device to the pipeline Fill the pipeline or section of pipeline with test gas at pipeline distribution pressure This filling procedure may also be used to measure the volume of the pipeline see Appendix 8 Disconnect and remove the gas supply Note the pressure and temperature initially and again at the end of the test period Version 2 0 June 2001 Page 209 of 264 Borders General Hospita
60. operating which indicates that the pump is drawing vacuum c an indicator of the vacuum produced in the pipeline Pump starter units There should be individual starter units each one operating a single designated pump The starters should be provideg gwith safety interlocks as specified by the pump manufacturers which s ibit plant operation until manually reset by means of a button T uld allow automatic restart after an interruption to the Each starter unit should contain the following an isolator interlocked with th either HRC fuses to BS 88 ors and or BS EN 60898 cuit breakers to BS EN 60947 2 le c starter d an industrial grade mmeter jo BS 89 e atotal hours r cluded in the plant control unit f agreen m n indicator if mounted separately from the plant contr Plant statu A monitoring System must be provided to detect the following faults in the vacuum supply system a plant faults for each pump i control circuit failed ii motor tripped iii pump failed to go on load iv activation of other safety devices supplied by the manufacturers a plant emergency receiver vacuum has fallen for example by 50 mm Hg 7 kPa below the cut in setting for the pump b pressure fault pipeline pipeline vacuum less than 360 mm Hg 48 kPa Version 2 0 June 2001 Page 126 of 264 Borders General Hospital NHS Trust on behalf of NHSScotland Property and Environme
61. operatingyro ventilation UCV system it may be have the services both medi the UCV system partial w pendant fitos the location of the vices should be taken into is prowded with an ultra clean acticable and cost effective to el ctrical incorporated as part of r The following installati s are sfpn ly deprecated wath body or other fluids are drawn through a fixed ing a terminal unit or other connector to a remote All terminal Waits should conform to BS 5682 1998 Terminal units intended for installationwith the socket axis horizontal i e wall mounted include a non swivel device so that directly connected equipment such as flow meters remain vertical terminal units intended for installation with the socket axis vertical for example in certain types of pendant do not include a non swivel device Secondary locks are no longer included in terminal units An anaesthetic gas scavenging AGS terminal unit should be provided whenever nitrous oxide is available for anaesthetic procedures In recovery areas when nitrous oxide is not provided where there is no primary source of anaesthetic gas pollution and or where nitrous oxide is used for analgesic purposes only no anaesthetic gas scavenging system AGSS is required Where nitrous oxide is provided for analgesic purposes scavenging is not practicable and pollution should be controlled by mechanical ventilation Details of ventilation requirements a
62. practicable Pipelines in stud or plasterboard walls or partitions are acceptable Care is required when selecting pipeline routes to prevent the pipes coming into contact with electric cables and wiring and to minimise the risk of electric shock in the event of a fault on adjacent cables See Chapter 2 Pipeline materials Quality The manufacturer should comply with BS EN SO Or pipes and for all materials including fittings terminal u omplete specification is given in Model Engineering Specifica C from other countries the ce with BS EN ISO 9000 Where materials are obtained from i suppliers should be registere Pipes Material for pipe to BS EN 197 phorus de oxidised non arsenical copper sions must be in accordance with BS EN 1057 NOTE For straight couplings expanded joints may be made instead of using BS EN 1254 fittings Other fittings Other fittings for connection to copper pipes for example valve and control panel fittings may be of copper brass gunmetal or bronze to the appropriate standard Version 2 0 June 2001 Page 162 of 264 Borders General Hospital NHS Trust on behalf of NHSScotland Property and Environment Forum 13 15 13 16 13 17 13 18 13 19 13 20 13 21 13 22 SHTM 2022 Part 1 Medical gas pipeline systems Cleaning Pipes All pipes must be cleaned and degreased for oxygen service and be free of particulate matter and toxic residues
63. provided the extract flow and pressure losses are within the specified limits Version 2 0 June 2001 Page 137 of 264 Borders General Hospital NHS Trust on behalf of NHSScotland Property and Environment Forum SHTM 2022 Part 1 Medical gas pipeline systems 10 49 The performance criteria for the disposal system are specified in the British Standard in terms of the extract flows at specified resistance as shown in Table 15 10 50 The performance criteria shown in Table 2 Anaesthetic gas scavenging systems should be achieved regardless of the number of terminal units on each system where more than one terminal unit is provided on the system the performance criteria should be achieved with all or one of the terminal units operative Table 16 Performance criteria for disposal systems Flow with a resistance to flow producing a Flow with a resistance to flow producing a ressure drop of 1 kPa ressure drop of 4 kPa Maximum flow 130 l min Minimum 80 l min Flow diversity 10 51 Although more than one AGS terminal room or anaesthetic room for conve be assumed that only one terminal unit will be in use at any ay also be assumed that the AGS terminal unit in the anaesthmt and in the operating room will not be in use simultaneously hen sizing the plant assume one receiving system only in alled in an operating Discharge outlet 10 52 Careful consideg given to siting the discharge outlet from the Smepre
64. pumps for medical vacuum plants cte plant manufacturers from the range of units curren e for industrial use New designs of vacuum pumps conti ap ar on the market Any type of pump may be used provided it ements of performance efficiency and reliability which are Rotary vane pumps ar replaced reciprocating optimised for dif reliability under maintained ry running rotary vane pumps are available at increased capital cost and with lower efficiency than oil lubricated pumps of comparable performance At least two pumps should be provided The actual number is at the discretion of the plant manufacturer to ensure optimum cost benefit of the system In all cases the total capacity must be at 75 of the system design flow with one pump not running All pumps should be designed for continuous operation All systems should comprise pumps and motors of identical type which are suitable for continuous running and stop start operation Pump motors should comply with the National Health Service Model Engineering Specification C51 with the addition of Class F insulation and Class B temperature rise Version 2 0 June 2001 Page 122 of 264 Borders General Hospital NHS Trust on behalf of NHSScotland Property and Environment Forum 9 25 9 26 9 2 7 9 28 9 29 9 30 9 31 9 32 9 33 9 34 SHTM 2022 Part 1 Medical gas pipeline systems A vacuum reservoir should be provided so that the duty pump does not run
65. purposes by gauge cocks Operating and indicating system The operating and indicating system should perforg the following functions overall plant control and indication individual compressor starting control of dryers plant status monitoring and indica ooo fF indication of the plant alarm sta Provided that the individu compartment these fu be installed ina comm wall Control pane release of presgg be appropriatelywde ssor Starters are housed in a separate carried out by separate units or may d located on the plant or on the plantroom mponents should have vents to permit t of component failure All indicators should znd should have a design life of at least one year The opera hould be capable of automatically restarting after reinstatem the power supply All components of the medical air supply system should be connected to the standby electrical supply The control system should ensure that compressors restart in sequence to avoid overloading the essential power supply Plant control unit The plant control unit should have a separate power supply for each compressor controlled by a separate sub circuit The unit should allow either manual selection of duty standby for each of the compressors or have an automatic sequence selection with a means for manual override The unit should ensure that two or more compressors do not start simultaneously when power is applied Version 2 0 Jun
66. safety requirements as for a pharmaceutical process This should include for example a HACCP analysis and other safety analyses which may be gecessary nd nitrogen ina the resultant mixture is always correct Continuous on line Ygonitaggg of oxygen concentration is provided to check th e system shuts down automatically in the event of out of s oncentration ifica In the event that one mixing system ts from the back up mixing syste wn the pipeline is supplied continuity of supply ore information on the details of the uired as well as operational information The feasibility study sh monitoring and alarm s Id prow tems r evaporator VIE system supplying the medical upply the synthetic air system depending on the the synthetic air system may also be used to provide ce for surgical tools instead of surgical air at 700 kPa An electrical power supply is required in order for example to operate solenoid valves and monitoring instrumentation Therefore the system should be on the essential power supply and connected via an uninterruptable power supply UPS with at least 4 hours capacity This should ensure continuity of supply in the event of power failure System description The gaseous oxygen and nitrogen are derived from bulk liquid supplies contained in a VIE as described in the Liquid oxygen supplies section of Chapter 6 The oxygen for synthetic air may be taken from the VIE
67. supply to patients is not compromised The section to be modified should be physically isolated from the section in use Closure of isolating valves is insufficient for this purpose Where area valve service units AVSUs have been installed the blanking spades should be used This isolation procedure is not required when work is to be carried out on individual terminal units Modification of existing systems may be detrimental to the overall performance of the system In the case of older systems there may be insufficient capacity to permit the system to operate safely with the flows typically encountered in use today Version 2 0 June 2001 Page 19 of 264 Borders General Hospital NHS Trust on behalf of NHSScotland Property and Environment Forum 2 2 2 28 2 29 2 30 2 31 2 32 2 33 SHTM 2022 Part 1 Medical gas pipeline systems Any work involving alteration extension or maintenance work on an existing system should be subject to the permit to work procedure see the Operational management part 2 of this SHTM Removal of pipework Removal and cutting out of redundant medical gas pipelines and equipment can present as great a hazard to patient safety as any other modification All such removal including cutting into existing pipelines capping off and removal of redundant pipeline and equipment should only be carried out by specialist medical gases contractors It should not be carried out by demolition
68. system should be designed to reject spurious radio frequency RF or mains noise typically arising in hospitals exampl eing diathermy equipment and current spikes caused by plan Relay conditions lf relays are used to transmit alarm in their normal closed condition lays should be energised Mains power supply The mains electricity su supply that is must b y Shou n the e derived from the essential power ergency system y be designed either as a safety extra low voltage ctional extra low voltage FELV system as defined SELV s separate metal enclosure The power supply should be rated for the full load of the panel with visual and auditory signals on all normal and alarm conditions Test facility Each panel should be provided with a means to test all visual and audible signals on that panel The power supply should be capable of sustaining all indicators and audibles Version 2 0 June 2001 Page 153 of 264 Borders General Hospital NHS Trust on behalf of NHSScotland Property and Environment Forum 12 31 12 32 12 33 12 34 12 35 12 36 SHTM 2022 Part 1 Medical gas pipeline systems Warning and alarm system faults General A flashing red visual indicator and an audible signal should operate on all panels when any of the following conditions occur a line fault from the initiating device b communication fault or other wiring fault c mains power failure Line fau
69. terminal unit base blocks are marked in accordance with BS 5682 1998 Sleeving and supports A visual check must be made on each pipeline system to ensure that the pipelines are sleeved and supported in accordance with the contract specification Leakage The aim of this test is to establish that there is nagreakage from the piped measuring equipment With suitable equipm le to make such measurements during a relatively short test piri may be more cost effective and will minimise errors whic e A a result of temperature change The pressure drop during a test peri 4 hours must be less than 0 025 per hour The pressu be corrected for variations due to temperature yy Appengs e testing any safety valves and pressure sensing devices installed may be removed and the connections blanked off lt is not desirable to cross link the carcasses to form a single system for the purpose of the carcass leakage test Cross connection The contractor must test for cross connection and document the results of these tests Version 2 0 June 2001 Page 189 of 264 Borders General Hospital NHS Trust on behalf of NHSScotland Property and Environment Forum 15 44 15 45 15 46 15 47 15 48 15 49 SHTM 2022 Part 1 Medical gas pipeline systems Requirements for pipeline system tests Leakage from total compressed medical gas systems There must be no links between the MGPS This test must be carried out on the pipelin
70. the pipeline systems During these tests pressure changes may occur which are caused by temperature changes rather than leakage 2 Pressure changes due to temperature difference may be calculated according to the Gas Laws 3 It is assumed that the temperature in the gfpeline is uniform in all branches If substantial runs are exter should be chosen Calculation 4 The change in gas pressur 5 P T P T where P4 pressures of a fixe final absolute te 6 bar absol Therefore P 7 Care value st be taken to express pressure and temperature in absolute 8 Pressure is normally expressed in gauge pressure Absolute pressure gauge pressure atmospheric pressure 9 Temperature is normally expressed in C Absolute temperature temperature in C 273 expressed in K 10 Absolute temperature K temperature in C 273 expressed in K Version 2 0 June 2001 Page 236 of 264 Borders General Hospital NHS Trust on behalf of NHSScotland Property and Environment Forum SHTM 2022 Part 1 Medical gas pipeline systems Examples 10 The carcass of a medical air pipeline is tested for leakage ata working pressure of 14 0 bar gauge pressure The temperature is 13 C at the beginning of the test and 17 C at the end of the test P 14 0 1 0 15 0 bara T1 273 13 286K To 2 3 17 290K 15x 290 Therefore P 15 21 bar absolute or 14 21 bar g that is gauge pressure should rea
71. then be running at the system design flow and the total system test can be carried out at each terminal unit for performance Version 2 0 June 2001 Page 245 of 264 Borders General Hospital NHS Trust on behalf of NHSScotland Property and Environment Forum SHTM 2022 Part 1 Medical gas pipeline systems Appendix 8 Procedure for measuring pipeline volume General A method is described to measure the volume of a compressed medical gas system with an acceptable accuracy Measurement principle A known volume of gas is delivered into a closed system from a cylinder The pressure changes in the system and the cylinder are noted Since the volume of the cylinder is Known the volume of pipeline system can be calculated The accuracy of the method depends upon t pressure changes ac of reading the Test equipment The following equipment is re a acylinder of test g not the volume of g js contaljed in the cylinder To achieve maximum accuracy It ed to charge the system for this test should be the smalles to fill the pipeline to the operating pressure b acyli e regulator fitted with an accurate gauge to measure cylind A gauge of at least 100 mm diameter with an appropr full scale reading is required 100 mm gauge to measure pipeline pressure This gauge should be calibrated in the same units as the cylinder pressure gauge d ameans of connecting the cylinder to the pipeline Procedure Establi
72. to the flow in each a realistic design flow The total f department ystem is the sum of the diversified flows to each The design ergineer should always ensure that due account is taken of the stated use of a particular department For example the number of terminal units in use for ward areas may be appropriate for a DGH but the number may need to be increased for a specialist chest department The pipeline is required however to meet the peak simultaneous demand and is designed accordingly The source of supply will usually be required to deliver a lower continuous flow lt must be remembered that there is a limited range of pipe sizes and that where there is any doubt about flow requirements a larger pipe size should always be selected All flows are in normal litres per minute l min unless otherwise stated Version 2 0 June 2001 Page 35 of 264 Borders General Hospital NHS Trust on behalf of NHSScotland Property and Environment Forum 4 10 SHTM 2022 Part 1 Medical gas pipeline systems NOTE At the design stage the project team should define the individual room space required The definitions which follow are generic and are not as detailed as those given in Table 2 Gas flow Terminal unit flows The following formula is used to calculate the volume flow required in the pipeline at pressure Pg upstream of each terminal unit Table 4 Gas flow flows required at terminal units Service Location
73. tting should be internally clean and free from oxides and particulate matter Some heat burnishing may be apparent and is acceptable Penetration Penetration of brazing alloy a due to tolerances of the capillary space on these pipes and fittings full penetration of the brazing alloy may not occur and is not necessary b the minimum penetration at any point on the joint must be three times the wall thickness of the tube or 3 mm whichever is greater Version 2 0 June 2001 Page 166 of 264 Borders General Hospital NHS Trust on behalf of NHSScotland Property and Environment Forum 13 39 13 40 13 41 13 42 13 43 13 44 13 45 13 46 SHTM 2022 Part 1 Medical gas pipeline systems Capping sections of pipeline should be capped as soon as they are completed to prevent the ingress of air Removal of flux residues and oxides The residue of flux and oxide resulting from the brazing of copper to brass gunmetal bronze fittings must be removed before components are delivered to site The following procedure should be used or alternatively one which is no less effective may be substituted Allow joints to cool naturally to room temperature or at least to a temperature at which they can be handled This is specifically for gunmetal fittings which if cooled or quenched from the brazing temperature by dipping in cold water could crack The flux residues should be removed by im hot water and
74. tubes give a quantitative response and are not intended for re use The tubes should be agent specific since non agent specific poly test tubes can respond to various agents such as volatile inorganic compounds giving misleading results A dewpoint meter could be used for water content These tests must be carried out on a represent in each system at the discretion of the QC T e sample of terminal units e must include as a should decide the number and locati tested These tests are Summarised Medical compressed air the pipeline distribution system plant should be tested for quality before d with the working gas Quality tests sho distribution sy C t on the plant as well as on the pipeline The test fo te matter should be carried out at every terminal unit It out either after completion of the construction phase or after been filled with the specified gas If after construction the system is to be left filled with medical air the particulate test would be completed first Once the system is filled with working gas it would not normally be necessary to repeat the test at every terminal unit The actual number of terminal units sampled is at the discretion of the QC It would however be necessary to repeat the test in full where there is insufficient evidence to show that a system has been satisfactorily maintained under pressure when left filled with medical air for the interim period The most dis
75. units should all be marked Do not use before modifications have started Terminal units are required to be supplied with such labelling affixed Special connectors will be needed to introduce test gas into different pipeline systems These must be of distinctive construction and permanently labelled with their function and the contractor s name The location of special connectors on the site must be recorded and should be subject to routine inspection under a planned preventative maintengvice PPM system procedures are outlined in paragraph s of the appropriate forms are given in Appendix 1 All si entitled to copies of the test forms The procedure for filin taining these forms should be the case of compresseqaair syst reduced below pi ib s the pressure at the plant must be n pressure All errors foun must be retested sg must be rectified and the relevant systems appropriate before the records are signed The contra provide all forms labour materials instruments and equipment r quired to carry out the tests described in paragraphs 15 37 15 85 This nmst include all cylinders of test gas together with medical gas probes and the test device described in Appendix 3 The quality controller QC should provide the test equipment specified in Appendices E and F The sequence of tests given in paragraphs 15 44 15 78 and 15 86 15 110 must be maintained Where a test is repeated one system at a time f
76. with a lighting level of 200 lux 20 lumens sq ft Noise control Plantrooms should be designed and constructed to ensure the satisfactory control of noise emission The effect of two vacuum pumps or compressors running together in the case of duplex installations and three or more in the case of multiplex installations will be to increase the free field noise level outside the plantroom by 5 dB A for each additional pump or compressor operation over and above the specified limits Consideration should be given to providing acoustic enclosures to reduce the free field noise levels in noise sensitive areas adjacent to plantrooms Version 2 0 June 2001 Page 178 of 264 Borders General Hospital NHS Trust on behalf of NHSScotland Property and Environment Forum 14 24 14 25 14 26 14 27 14 28 SHTM 2022 Part 1 Medical gas pipeline systems Acoustic enclosure and or plantroom design must not inhibit normal cooling functions or maintenance activities Free field noise levels should be given to the architect to assist in acoustic design of the plantrooms The discharge from some vacuum pumps may require silencing although it should be noted that rotary pump exhausts are not likely to require silencers Compressors and pumps should be mounted on properly selected anti vibration mounting where necessary to minimise transfer of noise and vibration to the structure of the building All pipework and electrical condui
77. yellow low pressure indicator for each bank to be illuminated after changeover when the pressure in the bank now running falls to the low pressure setting NOTE In practice conditions ii and iii are the same b for each emergency reserve bank a yellowidica r to be illuminated when the pressure in the bank falls belo ofr g fo nitrous oxide or below 68 bar g for other gases lw pressure and a red high respective conditions c for the pipeline distribution syste pressure indicator to be illumina occur whe Alarm signal status unit The following indication of manitol nditions should be provided Indication Legend a green no normal b yello empty change cylinders stan c yellow uty bank empty change cylinders immediately standby Yew d yellow emergency reserve reserve low banks low e red pipeline pressure fault pressure fault Conditions b to e should be transmitted to the central alarm system Where relays are used they should be normally energised relays which de energise under fault conditions with contacts having a minimum rating of 50V dc 50 mA Alternatively volt free normally closed contacts rated at 50 V dc 50 mA should be provided for transmission of conditions b to e to the alarm system Version 2 0 June 2001 Page 55 of 264 Borders General Hospital NHS Trust on behalf of NHSScotland Property and Environment For
78. yun snes jeubis wey S IUSUOGWIOO Sul JO pu4 901JJO s Jaeulbue Ul wJeje Jayeaday gjqeo uoleoiun QJOONINY JO IWSUCI ee 96po sjeuod JO WOOJ uoyd j Ul jaued Wee jeuan a6po s yod Ul wieje Joyeaday S IUSUOGWIOO Sul JO pu4 Page 148 of 264 Version 2 0 June 2001 Borders General Hospital NHS Trust on behalf of NHSScotland Property and Environment Forum SHTM 2022 Part 1 Medical gas pipeline systems Figure 17 Typical area alarm panel reproduced by kind permission of Shire Controls dD SUPPLY T PIPEWORK a PIPEWORK TO DEPARTMENT PRESSURE SENSORS END OF LINE COMPONENTS INTER CONNECT ING WIRING AREA ALARM PANEL Page 149 of 264 Version 2 0 June 2001 Borders General Hospital NHS Trust on behalf of NHSScotland Property and Environment Forum 12 10 12 11 12 12 SHTM 2022 Part 1 Medical gas pipeline systems System description System components Warning and alarm systems include the following functional elements a transmitters which convert the signal from the plant or manifold volt free alarm contacts into a form which can be transmitted
79. 2 The particulate contamination of all pipeline systems may be checked using dry oil free medical air to establish that the pipeline has been constructed correctly and is not contaminated Successful completion of the commissioning tests normally indicates the end of the installation contract The systems may then be left under pressure filled with medical compressed air for an indefinite period Responsibility for the system during this period needs to be clearly defined in the contract NOTE Systems that are not to be taken immediately into use should be filled with medical air and left under pressure Nitric oxide systems should be filled with oxygen free nitrogen Because of the possibility of oil contamination systems other than medical air supplied from compressors should be filled with medical air from cylinders Version 2 0 June 2001 Page 181 of 264 Borders General Hospital NHS Trust on behalf of NHSScotland Property and Environment Forum SHTM 2022 Part 1 Medical gas pipeline systems Table 22 Personnel and test equipment requirements Paragraph Test Personnel Equipment Pipeline carcass CSO amp CR 15 37 Labelling and marking CSO amp CR 15 38 Sleeving and supports CSO amp CR Pressure device 15 39 Leakage CSO amp CR 15 43 Cross connection CSO amp CR Pipeline system 15 44 Leakage CSO CR amp AP Pressure device 15 50 Area value service units CSO CR P Pressure device 15 58 Cross connection 15
80. 2 0 June 2001 Page 130 of 264 Borders General Hospital NHS Trust on behalf of NHSScotland Property and Environment Forum SHTM 2022 Part 1 Medical gas pipeline systems 10 14 There are several different types of breathing circuit which can be used to administer the anaesthetic gases to the patient depending on the procedure to be carried out Nearly all breathing circuits apart from paediatric circuits incorporate an expiratory valve or port in the case of a ventilator to which a scavenging system can be connected 10 15 The major source of pollution when a general anaesthetic is administered is spillage from the expiratory valve or adjustable pressure limiting valve on the breathing system or from the expiratory port of the ventilator This valve needs to be replaced with a modified valve to which a scavenging system can be connected The characteristics of these valves may vary with orientation there may be a further variation when a scavenging system is connected The anaesthetist will need to be aware of this and adjust the valve as appropriate 10 16 Both the expiratory valve and the expiratory port ofgthe ventilator should comply with the requirements of BS EN 737 an 740 so that a scavenging system can be connected 10 17 The expired gas flow depends on whether the pati breathing spontaneously or whether a ventilato ing Used and if so the type of ventilator Typically the expired gas fl x can h 130 I min al
81. 2022 Part 1 Medical gas pipeline systems Safety note this is not the initial alarm condition of the system The VIE see user manual is supplied with a differential pressure switch for liquid level alarm The VIE user manual should describe in detail the operation and actions necessary should this alarm condition be initiated The VIE level alarm and standby in use alarm will remain on until the VIE is refilled Standby low Should no action be taken after VIE supply failure the standby system will supply until pressure falls to a pre set pressure at which time a standby low alarm will be given Low line pressure Gas usage without VIE or cylinder replenishm drop At an outlet pressure of 3 75 bar g a given This alarm condition will also be initiat within the control panel failing shut or afai High line pressure If a regulator within the contr goangr f line pressure will be giv t bar g open a high pressure alarm high Emergency shutdown e blowing upply to vaporiser to reduce VIE pressure to ii no supplier immediately b in case O vessel bursting disc blowing i close valve liquid supply to vaporiser to reduce VIE pressure ii check that VIE pressure is below 16 0 bar g iii Change valve to alternative bursting disc position iv notify the gas supplier immediately VIE filling After commissioning subsequent filling of the VIE is controlled by the gas
82. 255 of 264 Borders General Hospital NHS Trust on behalf of NHSScotland Property and Environment Forum SHTM 2022 Part 1 Medical gas pipeline systems Figure 21 Pressure settings for 400 kPa systems BOO Bo SAO et Safety valve setting eo itet pressure 530 kPa Pan 510 FI Set pressure 48 igh ee switch uracy 495 set pressure 460 460 A Da Sel pressure 440 kPa Lire pressure regulat boerance i d Larn vary betwen 460 and 10 420 Pipeline aperating range 400 Allowable pressure boss 420 380 kPa 375 at tront of terminal umit Set pressure 365 kPa THI 355 Lowy lew pressure Sitch san accuracy 455 of sof pressure Version 2 0 June 2001 Page 256 of 264 Borders General Hospital NHS Trust on behalf of NHSScotland Property and Environment Forum SHTM 2022 Part 1 Medical gas pipeline systems References NOTE Where there is a requirement to address a listed reference care should be taken to ensure that all amendments following the date of issue are included ID Acts and Regulations The Building Scotland Act Clean Air Act Electricity Act Health and Medicines Act Health and Safety at Work etc Act Medicines Act Public Health Act Sewage Scotland The Water Water Indus y Act Ac SI 2179 amp tandards Scotland 187 i amended ing Standards Scotland Technical Standards Eyidance SI 1460 emicals Hazard Information and Packaging for Supply Regulations CHIP2 SI 3140
83. 40V supply this should be on the emergency supply and an uninterruptible power supply should also be provided with at least 4 hours capacity Each isolatable vaporiser or set of vaporisers must have a safety relief valve Medical oxygen flow control A control panel similar in principle to a C11 panel should be provided the only difference is that the standby supply is from a low pressure liquid source instead of high pressure cylinders Surgical nitrogen flow control A control panel to regulate the gaseous nitrogen to between 7 5 and 9 5 bar g depending on the system design should be provided The pipeline distribution system should be desi as for surgical air 700 kPa systems as descaib exactly the same way r 8 Control panel for the nitrogen and o panels en to the mixing pp The control panel should be sized flows as appropriate for the 200m hr O provide pressure regulated is would typically be up to J The standby supply reg lation bar g there is no rogala on ts iN when the main line pressure falls to 11 e main supply line ould also be installed on both the main oxygen supply y oxygen supply to the mixer to prevent the medical oxygen ontaminated with nitrogen Air mixing panels A range of sizes of mixing panels are available with typically nominal capacities of 50 100 and 200m hr A regulated supply of nitrogen and oxygen is mixed in a mixing valve The di
84. 63 Flow and pressure drop Special test device 15 64 Mechanical function Test probe 15 65 Gas specificity 15 66 NIST connectors 15 68 System performance Metered leaks and special test device 15 72 Supply syste 1s CSO CR amp AP 15 74 CSO CR amp AP 15 76 CSO CR amp AP 15 78 CSO amp AP 15 79 15 86 CSO amp CR 15 88 articulate contamination and CSO CR QC amp AP Particulate matter quality tester oil water CO and CO measuring devices 15 106 Gas identification CR QC amp AP O analyser and NO meter 15 118 Anaesthetic gas scavenging CR amp AP AGS test device and system induced flow test device Key CR Contractor s representative AP Authorised person MGPS CSO Contract supervising officer QC Quality controller Version 2 0 June 2001 Page 182 of 264 Borders General Hospital NHS Trust on behalf of NHSScotland Property and Environment Forum SERVI ne 1e y l SHTM 2022 Part 1 Medical gas pipeline systems AND Eyyy roS Figure 20 Decision tree for testing and commissioning Pre contract works Extension Modification to existing system z Test existing system for performance Install system to carcass Prepare total system first fix stage performance specification Visual checks Valves leakage cross connection Carry out remedial work Carry out carcass tests ad Carry out remed
85. 64 4 65 4 66 4 67 SHTM 2022 Part 1 Medical gas pipeline systems required for the remainder This is approximately equivalent to a maximum of three terminal units in use simultaneously in a six bed room In a typical ward comprising four six bed rooms four single bed rooms and a treatment room for the purpose of calculating the diversified flow QW to the ward the number of terminal units used in Table 10 may be taken as number of terminal units in the ward A department may comprise several ward units and treatment suites The diversified flow for each department QD is based on QW for the first ward unit plus 50 of the flow for the remaining ward units Surgical air 700 kPa Flow and pressure requirements for 700 kPa surgical air system pressures are likely to cause damage however is likely to result from the la adequate tool performance the specified pressure The introduction of synthetic air fro blending of oxygen and nitrogen leads to the possibi itrogen as the power source for surgical tools Synthetic ed in Chapter 7 System design medical air The pipeline syste 700 kPa at the simi w 46 Sipe the pressure drop at a flow of 350 l min will theSssessure drop at 250 l min be about Diversity Surgical air 700 kPa is only required where surgical tools are to be used This would typically be orthopaedic neuro surgery theatres and possibly plaster rooms However to facilitate
86. Borders General Hospital NHS Trust on behalf of NHSScotland Property and Environment Forum 12 13 12 14 12 15 12 16 12 17 12 18 12 19 12 20 SHTM 2022 Part 1 Medical gas pipeline systems General requirements Labelling All visual signal panels should be permanently labelled according to their function including clear identification of the areas rooms or departments served Visual signals Flashing visual signals should have alternate periods on and off each of equal duration between 0 25 and 0 50 seconds There should be two separately energised light sources for each signal arranged so that the failure of one source does not affect the other The light sources should have a design life of at continuous operation st five years of Audible signals All audible signal tones should be m ula between two tones of 440 Hz 10 ally at a rate of 4 Hz 10 0 Hz 10 Automatic re setting When a warning or alargy si rs and the system condition subsequently reverts t e corresponding visual and audible signals should automatic Temporary m Means m roed on each panel for the user to mute the audible signal The st re sound after a nominal 15 minute period if the fault condition sti exists The process of muting and reinstatement of the signal should be rep pated until the fault condition has been rectified Operation of the mute should be accompanied by change from flashing to st
87. Borders General Hospital NHS Trust on behalf of NHSScotland Property and Environment Forum 9 35 9 36 9 37 9 38 9 39 9 40 9 41 9 42 9 43 SHTM 2022 Part 1 Medical gas pipeline systems Pressure control The cut in setting for the vacuum pumps should be adjusted to allow for the pressure drop across the pipeline distribution system and the bacteria filters The cut in may be expected at about 500 mm Hg 67 kPa The cut out setting should be at an appropriate point on the performance curve of the pump which minimises stop start operation but is at a vacuum which is economically attained by the pump This cut out setting may be expected at about 650 mm Hg 87 kPa Valves Non return valves should be fitted when necessary at the inlet and outlet of each pump to prevent backflow when a common discharge pipe is used Some vacuum pumps include integral non return yalves Manually operated valves should be arranged Figure 13 to allow isolation of components pass pipework drainage taps and bacteria fil Pressure regulation of vacuum sy A vacuum of 300 mm Hg is require th amp connection point of each terminal unit with a flow of 40 I min w thes m is operating at system design flow Procedures for these tests are g yen in Chapter 15 13 kPa is allowed across the terminal unit 622 1998 A further pressure drop of 50 mm Hg petween the terminal unit connection point and the s
88. Construction Design and Management Regulations SI 437 Control of Substances Hazardous to Health Regulations COSHH SI 3260 Electrical Equipment Safety Regulations SI 635 Electricity at Work Regulations SI 1057 Electricity Supply Regulations as amended Version 2 0 June 2001 Page 257 of 264 Borders General Hospital NHS Trust on behalf of NHSScotland Property and Environment Forum SHTM 2022 Part 1 Medical gas pipeline systems SI 2372 Electromagnetic Compatibility Regulations as amended SI 2451 Gas Safety Installation and Use Regulations SI 917 Health amp Safety First Aid Regulations SI 682 Health amp Safety Information for Employees Regulations SI 2792 Health and Safety Display Screen Equipment Regulation SI 341 Health and Safety Safety Signs and Signals Regulations SI 1380 Health and Safety Training for Employment Regulations SI 917 Highly Flammable Liquids and Liquefied lt Ja Petroleum Gases Regulations SI 2307 Lifting Operations and Lifting Equipmen Regulations LOLER SI 3242 Management of Health a Work Regulations SI 2793 Manual Handling O SI 1790 SI 3139 SI 2966 SI 128 SI 2306 NISIA and Use of Work Equipment egulations PUWER SI 3163 Neporting of Injuries Diseases and Dangerous Occurrences Regulations RIDDOR SI 3004 Workplace Health Safety and Welfare Regulations British Standards BS 88 Cartri
89. In the event of failure onthe mail VIE the standby system should come into operation auto ould be a non return valve to protect the standby system 4 through the VIE in the event of a fault Back up i storage vessel 6 45 This shoul ized to provide 24 hours supply at 50 capacity 6 46 To prevent unviecessary gas losses the economiser circuit should be piped into the main supply distribution system downstream of the main vaporiser 6 47 The back up vaporiser should be sized to provide 24 hours usage at average flow rates Liquid cylinder back up 6 48 The number of liquid cylinders required will depend on the flow rate requirements rather than the capacity 6 49 To prevent unnecessary gas losses the economiser circuit should be piped into the main supply downstream of the main supply vaporiser Version 2 0 June 2001 Page 72 of 264 Borders General Hospital NHS Trust on behalf of NHSScotland Property and Environment Forum 6 50 6 51 6 52 6 53 6 54 6 55 6 56 6 5 7 6 58 SHTM 2022 Part 1 Medical gas pipeline systems Compressed gas cylinder back up The minimum size of the back up manifold should be a 2 x 5 J size cylinders There should be sufficient additional cylinders on site to provide adequate back up and arrangements should be made to ensure that 24 hours supply is available Emergency supply facility Where a risk assessment has identified a potentially vulnerable situation
90. N2O0 O2 MA 4 Surgical Air VAC Witnessed on beii By Signed Version 2 0 June 2001 Page 232 of 264 Borders General Hospital NHS Trust on behalf of NHSScotland Property and Environment Forum SHTM 2022 Part 1 Medical gas pipeline systems Medical Gas Pipeline Total System Tests Form B13 Sheet of Sheets Hospital Scheme File Number Date Purging and Filling This is to certify that medical gas systems have been purged and filled with the working gases in accordance with paragraphs 15 79 15 85 and or 15 86 15 87 as follows Action N2O O gt Surgical Air VAC Special Connectors Cylinders removed from site Filling Purging all Terminal Units Venting Contractor s pres ive Status Signed Date Name Contract Supervising Officer Status Signed Date Name Witnessed on behalf of By Status Signed Date Version 2 0 June 2001 Page 233 of 264 Borders General Hospital NHS Trust on behalf of NHSScotland Property and Environment Forum SHTM 2022 Part 1 Medical gas pipeline systems Medical Gas Pipeline Total System Tests Form B14 Sheet of Sheets Hospital Scheme File Number Date Quality This is to certify that medical gas pipeline systems have been tested in accordance with paragraphs 15 88 15 105 as follows Tick when specification is met N20 02 Medical Air Surgical Air matter A L ea ND SE O C O E y Water a 15 ars ga T K O o swm M WANS lt 5 ppm N ee ee o lt 500 p
91. NGREGATE Version 2 0 June 2001 Page 69 of 264 Borders General Hospital NHS Trust on behalf of NHSScotland Property and Environment Forum SHTM 2022 Part 1 Medical gas pipeline systems SAFETY DISTANCES FOR LIQUID OXYGEN STORAGE 20 TONNES TO 200 TONNES NET LIQUID CAPACITY DISTANCES IN METRES AREAS WHERE OPEN MV amp HV LARGE WOODEN SMALL STOCKS OF FUEL GAS FLAMES SMOKING SUB STRUCTURES COMBUSTIBLE VENT PIPES ARE PERMITTED xX STATIONS TIMBER YARDS MATERIAL SITE HUTS ETC WORK SHEDS ETC l A 8 FLAMMABLE GAS CYLINDER STORAGE VEHICLE PARKING AREAS OTHER THAN AUTHORISED PROCESS EQUIPMENT amp MACHINERY WHICH IS NOT PART OF THE STORAGE INSTALLATION ead ala L P G STORAGE PUBLIC ROADS RAILWAY LINE CONTINUOUS SECTIONS OF PIPELINES CONTAINING FLAMMABLE GASES OR LIQUIDS NOT INTERRUPTED A BY FITTINGS eg VALVES UNIONS FLANGES ETC BULK FLAMMABLE LIQUID STORAGE i X PITS DUCTS COMPRESSOR FLANGES UNIONS OFFICES CANTEENS PLACES OF SURFACE WATER VENTILATOR IN PIPELINES amp AREAS WHERE PUBLIC DRAINS UNTRAPPED AIR INTAKES CONTAINING EMPLOYEES ASSEMBLY OPENINGS OF SYSTEMS FLAMMABLE VISITORS ARE LIKELY GASES OR LIQUIDS TO CONGREGATE BELOW GROUND LEVEL Page 70 of 264 Version 2 0 June 2001 Borders General Hospital NHS Trust on behalf of NHSScotland Property and Environment Forum 6 33 6 34 6 35 6 36 6 37 6 38 6 39 SHTM
92. NHS Trust on behalf of NHSScotland Property and Environment Forum SHTM 2022 Part 1 Medical gas pipeline systems Figure 7 Safety distances for cryogenic storage vessels reproduced by kind permission of BOC and BCGA SAFETY DISTANCES FOR LIQUID OXYGEN STORAGE UP TO 20 TONNES NET LIQUID CAPACITY DISTANCES IN METRES Y i i E AREAS WHERE OPEN MV amp HV LARGE WOODEN SMALL STOCKS OF FUEL GAS FLAMES SMOKING SUB STRUCTURES COMBUSTIBLE VENT PIPES ARE PERMITTED x STATIONS TIMBER YARDS MATERIAL SITE HUTS K ETE WORK SHEDS ETC y va FLAMMABLE GAS CYLINDER STORAGE la VEHICLE PARKING AREAS OTHER THAN AUTHORISED x PROCESS EQUIPMENT amp MACHINERY WHICH iS NOT PART OF THE STORAGE INSTALLATION ua O a L P G STORAGE PUBLIC ROADS RAILWAY LINE PROPERTY BOUNDA S Pa 5 P EN L E CONTINUOUS SECTIONS TF SON PIPELINES CONTAINING soy be N FLAMMABLE GASES OR 4 LIQUIDS NOT INTERRUPTED a F BY FITTINGS eg VALVES BULK FLAMMABLE y UNIONS FLANGES ETC LIQUID STORAGE pt AG 5 gt DEn l E PITS DUCTS COMPRESSOR FLANGES UNIONS OFFICES CANTEENS PLACES OF SURFACE WATER VENTILATOR IN PIPELINES E oe lies PUBLIC DRAINS UNTRAPPED AIR INTAKES CONTAINING a ae 7 ASSEMBLY OPENINGS OF SYSTEMS FLAMMABLE se n ate BELOW GROUND LEVEL GASES OR LIQUIDS O CO
93. NHSScotland Property and Environment Forum 15 192 15 193 15 194 15 195 15 196 15 197 15 198 SHTM 2022 Part 1 Medical gas pipeline systems Record the results on Form B12 if the drawings are in accordance with paragraph 15 78 Filling with medical air When an indefinite period may elapse before the system is taken into use it should first be tested for particulate contamination using medical air as the test gas in accordance with paragraphs 15 79 15 85 Procedure The procedure in paragraphs 15 79 15 85 should be followed for the particulate contamination test only in accordance with paragraphs 15 95 and 15 96 If the test is satisfactory the system should be filled with medical air and left pressurised at pipeline distribution pressure Results d oneForm B13 which tested with If the results are satisfactory they should begre should be annotated to indicate that the syst medical air h Special connectors r At the end of the contract peri special connectors are re tor should ensure that any Purging and filling wit speci General The following sh specific g sy time be carried out prior to purging and filling with the s may be filled with their specific gases at the same all previos tests should have been satisfactorily completed b each pipeline system should be connected to its source of supply with all AVSUs open c all sources of t
94. Nominal Flow litres min pressure kPa Design flow Typical flow required Oxygen Theatre 20 All other areas 6 Nitrous oxide All areas 6 Nitrous Delivery rooms 275 20 oxide oxygen All other areas 20 15 mixture Medical air Theatres 400 40 40 400 kPa ITU neo 400 80 80 CCU 0 80 80 400 20 10 Surgical 700 350 350 air nitrogen Vacuum 40 40 40 300 mm Hg 40 40 below 40 40 d areas atmospheric 40 40 Nitric oxide ITU neonatal 400 15 6 theatres Oxygen carbon Cardio thoracic 400 100 40 dioxide mixture theatres oncology a During oxygen flush in operating and anaesthetic rooms Minimum pressure at 275 I min c These flows are for certain types of gas driven ventilators under specific operating conditions and nebulisers etc Surgical tools tourniquets Pressure required at terminal unit not in pipeline Version 2 0 June 2001 Page 36 of 264 Borders General Hospital NHS Trust on behalf of NHSScotland Property and Environment Forum 4 11 4 12 4 13 4 14 4 15 4 16 4 17 4 18 SHTM 2022 Part 1 Medical gas pipeline systems The flow Qa required at a terminal unit is expressed in terms of free air flow at standard temperature and pressure STP The relationship between volume flow Qa at STP and the volume flow Qg at the pipeline pressure Pg iS Qg Qa x Ap Pg Were Ap atmospheric pressure absolute Pg pipeline pressure absolute NOTE For manual calculations
95. S WdI1SAS 1 SuL1 Buiyjyeaug O S WI O S WI Buign sojsuesy AIS PA J umeors Joljeu ounssoaid J isod Jo sues UOIO9UUOD jeO1UOD WWOE UONODBUUOD JUBUB Wd oe w S S L soy q X 4 BUIAI9D91 JOJSUBI eiBalul Bullesodiooul snjeseddy Page 134 of 264 Version 2 0 June 2001 Borders General Hospital NHS Trust on behalf of NHSScotland Property and Environment Forum SHTM 2022 Part 1 Medical gas pipeline systems Figure 15 Schematic diagram of receiving system reproduced by kind permission of MEC Ltd Flow to disposal system Filter pore size 150um Surface area 44cm Flow indicator ic fro fer system r i Omm f nnector RS Identification label ma Protective cage Version 2 0 June 2001 Page 135 of 264 Borders General Hospital NHS Trust on behalf of NHSScotland Property and Environment Forum 10 36 10 37 10 38 10 39 10 40 10 41 10 42 10 43 10 44 SHTM 2022 Part 1 Medical gas pipeline systems Passive systems are those in which the air flow from the disposal system does not result from a powered device The patient provides the driving force to expel the gases Passive systems are not recommended This is because they cannot meet the specified safety re
96. SScotland Property and Environment Forum SHTM 2022 Part 1 Medical gas pipeline systems Medical Gas Pipeline Total System Tests Form B6 Sheet of Sheets Hospital Scheme File Number Date Cross Connection Test This is to certify that a CROSS CONNECTION test in accordance with paragraph 15 58 15 62 was Carried out on the following medical gas pipeline systems Contractor Status Signed Date Name Contract Supervising Officer Status Signed Date Name Witnessed on behalf of By Status Signed Date Version 2 0 June 2001 Page 225 of 264 Borders General Hospital NHS Trust on behalf of NHSScotland Property and Environment Forum SHTM 2022 Part 1 Medical gas pipeline systems Medical Gas Pipeline Total System Tests Form B7a Sheet of Sheets Hospital Scheme File Number Date Functional Tests of Terminal Units in accordance with the Contract Specification and paragraphs 15 63 15 65 System Specified Flow min Specified Pressure Drop kPa Specified Specified Pressure TERMINAL Rott e Mechanical Gas UNIT NUMBER Function Specificity _ Contractor s Repre a Status 3 Date y Name Contract Supervis ag Officer Status Signed Date Name Witnessed on behalf of By Status Signed Date Version 2 0 June 2001 Page 226 of 264 Borders General Hospital NHS Trust on behalf of NHSScotland Property and Environment Forum SHTM 2022 Part 1 Medical gas pipeline systems Medical Gas Pi
97. SScotland Property and Environment Forum SHTM 2022 Part 1 Medical gas pipeline systems sS we ENV a Figure 8 Typical liquid cylinder installation reproduced by kind permission of BOC PSL COMPRESSED CYLINDERS P a a al 5a ve fr 5 WO gt lt _ i X ble rami y R a Y j g x 4 Zo AMT 525 y i gt lt S Z h fo IF M y i y N g y X 5 pe y X Yo v g Version 2 0 June 2001 Page 76 of 264 Borders General Hospital NHS Trust on behalf of NHSScotland Property and Environment Forum 6 70 6 71 6 2 6 73 6 74 6 75 6 76 6 7 7 6 78 6 79 6 80 SHTM 2022 Part 1 Medical gas pipeline systems The standby supply feeds into the control panel and in the event of the liquid cylinder pressure dropping below a pre set value a flow of oxygen will commence automatically This ensures that a constant supply of oxygen at the correct pressure is maintained Emergency compressed oxygen manifold The emergency oxygen supply consists of a manual or automatic changeover manifold which comes into operation automatically The ma
98. SUs AVSUs are provided for user acc in purposes They comprise a ball val lockable door permitting locki emergency operation s AVSU should provide pipeline both upstream emergency or for maintenance ed within an enclosure with open or closed The means of introduce the possibility of injury The ically isolating and blanking off the stream of the valve The means of isolation both the pipeline and the valve port and be n the event of leakage of the blanking device gas ust not be able to enter either the valve port or INS ans fo d do In an emer y the user must be able to gain access in order to operate the isolating Valves quickly and simply without the need for a key There are several methods of providing such emergency access for example break glass panels plastic push out inserts etc Whichever method is used must be safe and secure but must not provide a risk of injury to the user The method of emergency access must be obvious and clearly labelled and its use must be evident The appropriate NIST connector bodies with self sealing check valves captive plugs or caps should be provided upstream and downstream of the blanking plate AVSUs may be designed for a single pipeline service or multi services Where the cover bears the name of the gas service it should be gas specific In the case of multi service AVSUs the design should be such as to permit the attachment of a hose assembly to an
99. System design medical air Compressor systems for medical air 400 kPa General The major components of a medical air system and their layout are shown in Figure 10 A suitable operating and indicating system is also required as specified below Appropriate layout and adequate siting of these components should be provided Package supply systems which should be specified to meet the requirements given in this memorandum are available from manufacturers Quality The required quality level for medical air is s eci b EN 132 1991 The requirements for maximum conce tration are nin Table 1 The European Pharmacopoeia Ph Eur ximum impurity levels for nitrogen monoxide and dioxide moisture and oils In futuresy e necessary for provision to be made to control the level of t inadnts and to monitor the supply to ensure conformance with Siting Aall access for maintenance purposes and Je for changing major components The siting gas different p Apo a air intakevio the compressors b cooling of the compressed air by the after coolers c cooling of the compressors Each compressor may require ducting to ensure an adequate flow of cool air The manufacturer should be consulted over the range of operating temperature for which the system is designed Air inlet filters should be fitted immediately upstream of the compressor In exceptional circumstances additional screens filters and silencers may be requi
100. TE ie ref only O _ a So RO 5 Hp OJ 0 03 x 1 CO All Diameters Be Hose insert or NIST fitting see unless otherwise a stated 46 min Surface Finish 1 6 unless otherwise stated Oo N Indexing collar to be irremovable b Enlarged pa N o c Dimensions of optional nose locating slot of indexing collar 6395 050 0 ag Re oe 3S min FT OO gt LO T gjo 2 l F Y Lo ee ie Sharp 7 corners z ROS 9 with finish required re rea where service Slot to be in same plane manufacturers ID and BS as angled hose insert see number should be stamped figure 3 and 11 1 3 Version 2 0 June 2001 Page 31 of 264 Borders General Hospital NHS Trust on behalf of NHSScotland Property and Environment Forum SHTM 2022 Part 1 Medical gas pipeline systems Diameters of body of NIST connectors Service Identification Diameter Diameter symbol E F Nitric oxide 11 00 0 11 14 00 0 11 0 0 0 0 19 06 0 15 15 06 0 15 6 06 0 15 0 05 X eo a g 1 O So i i G o Oo S a0 N a p 2 O D ne gt oS E TEN 1 cO i 1 ELD a 0 70x45 min An FT 0 max OS PSF NOTE Diamet F location of fac h
101. VSUs and the warning systems have been labelled in ad ordance with the contract specification and are labelled or will be labelled prior to formal use in a secure manner to state where they serve All certificates must be dated and signed by the appropriate witnesses by the contract supervising officer and by the representative of the contractor For modifications or extensions to existing systems the performance tests for flow and pressure drop as described in paragraph 15 68 must be carried out on the completed system using the working gas If the performance is in accordance with the specification prepared as described in paragraphs 15 29 15 36 the system may be taken into use provided that all the other tests have been satisfactorily completed Version 2 0 June 2001 Page 203 of 264 Borders General Hospital NHS Trust on behalf of NHSScotland Property and Environment Forum 15 115 15 116 15 117 15 118 15 119 15 120 15 121 SHTM 2022 Part 1 Medical gas pipeline systems Operational policy A procedure must be available in accordance with the Operational management part 2 of this SHTM and must ensure continuity of supply of cylinders and bulk liquid This will incorporate a procedure for recording delivery handling and storage of full and empty cylinders with an indication of who is responsible for these activities the composition of the cylinder contents must be certified by the supplier All de
102. above In this case only one system at a time is pressurised Procedure The procedure is as follows a before commencing the tests check that the test equipment meets the requirements given in Appendix 3 for the system under test All terminal units should be complete with the fascia plat b insert the test device described in Appen each terminal unit in c check that the gas specific prob rted captured and released and that it does not tally mounted terminal units and that it can swivel with e force in vertically mounted d check that no gas is t each terminal unit by the probes for all other gases used bes can be engaged e check that all s accept the NIST probe for the correct gas and the onnection is made Check that the NIST ses do not make mechanical connection NOTE NI S s see paragnie f note that the NIST self sealing device functions as specified in paragraph 15 67 Results Record the results on Form BZA if they are in accordance with paragraphs 15 63 15 67 Note numbering Performance tests of the pipeline system These tests should be carried out on one system at a time All AVSUs should be open Connect a supply of test gas at the supply source of sufficient capacity to meet the total design flow of the system The vacuum supply system may be used to test the vacuum pipeline system as described in Appendix 7 Version 2 0 June 2001 Page 212 of 264 Borders General Hospital
103. acal If this face is movable z 7 part of a check valve Bnould be provided to prevent its move t to a depth greater than 19 00mm Finish to b 1 6 For vacuum service the diameter of MSN enS 12 90mm extends over the full depth of 19mm and this chamfer will unless otherwise stated wu appear at the nose of the fitting All dimensions are in millimetres Version 2 0 June 2001 Page 32 of 264 Borders General Hospital NHS Trust on behalf of NHSScotland Property and Environment Forum SHTM 2022 Part 1 Medical gas pipeline systems Diameters of nipples of NIST connectors Service Identification Diameter Diameter symbol H J Nitric oxide 11 00 0 05 14 00 0 05 0 16 0 16 OQ Rings to BS 4518 Ref No 0076 24 recommended hardness 75 LR H D 14 min 0 8 i 0 8 0 8 i i ence OS x OoOo oO 2 5 xr gt i Q lo Q ae a gt 8 G l l x O0 03 y 5 06 0 15 Q10 03 X 56 0 15 n 18 56 0 15 Surface Finish 1 6 unless otherwise stated All dimensions a es NOTE It has been P that gas tightness and 5G smooth operation d A when the O ring is I compressed between rs2mm and 0 134mm on diameter re under maximum and imum tolerancing conditions Se 1 FOFO 0 20 7 56 0 1 12 06 0 15 off Version 2 0 June 2001 Page 33 of 264
104. age 238 of 264 Borders General Hospital NHS Trust on behalf of NHSScotland Property and Environment Forum 11 12 13 14 15 16 SHTM 2022 Part 1 Medical gas pipeline systems Where it would be impractical to use gas specific probes it is permissible to use a specially designed universal probe provided it is impossible for such a probe to be improperly used on medical equipment The special probe should be clearly marked test only Test probes for gas specificity The gas specific probe for each service should be as specified in BS 5682 1998 Orifices The orifices should be selected from the information on the manufacturer s data sheets or from practical testing These devices should be checked against a flowmeter before use Flowmeter A bobbin flowmeter calibrated to a flow of 40 Ymi a used to measure flow under vacuum Pressure gauge A 50 mm bourdon gauge wit should be used as follows na riave full scale reading and interval Test pressure kPa le Scale interval 400 0 7 bar 0 1 bar 700 0 11 bar 0 5 bar Vacuum 0 760 mm Hg 50 mm Hg 0 100 kPa 5 kPa Note 1 bar 100 kPa approx Version 2 0 June 2001 Page 239 of 264 Borders General Hospital NHS Trust on behalf of NHSScotland Property and Environment Forum SHTM 2022 Part 1 Medical gas pipeline systems Appendix 4 Membrane filter test device General The function of this test device is to collect p
105. age 251 of 264 900 800 700 600 500 400 300 200 100 42mm SHTM 2022 Part 1 Medical gas pipeline systems Vacuum at 450mm Hg 60 kPa 35mm 28mm D 3 3 0 25 0 5 0 75 1 1 25 1 5 1 75 Note all lines are applicable to pressure loss Version 2 0 June 2001 Hg and 50mm Hg 1 3 kPa 2 7 kPa 4 0kPa and 6 7 kPa Borders General Hospital NHS Trust on behalf of NHSScotland Property and Environment Forum Page 252 of 264 6 25 Free air flow l min 12000 10000 8000 6000 4000 2000 SHTM 2022 Part 1 Medical gas pipeline systems Pressure loss data
106. air 7 1 General 7 2 Quality ia Siting 17 1 Compressor noise 7 9 Air intake 7 10 LI 7 21 7 22 7 24 nent and filtration General Solid contaminants 7 29 Water 7 31 Ol 7 39 Dryer controls 7 40 Dust filters 7 42 Activated carbon filter 7 43 Bacteria filters 7 44 Pressure control 7 45 Test point 7 46 Safety valves 7 48 Traps and valves 7 48 Automatic drainage traps 7 50 Non return valves 7 51 Isolating valves Page 6 of 264 Borders General Hospital NHS Trust on behalf of NHSScotland Property and Environment Forum SHTM 2022 Part 1 Medical gas pipeline systems 7 52 Pressure indicators 7 53 Operating and indicating system 7 61 Plant control unit 7 64 Plant control indication 7 65 Compressor starter units 7 66 Dryer control unit 7 68 Plant status monitoring 7 69 Plant indicator unit 7 2 Alarm signal status unit 7 Plant management 7 78 Operating considerations 7 79 Synthetic air 7 79 General 7 88 System description 7 95 Storage vessels 7 95 Vessel sum 7 96 7 97 7 104 Vaporisat 7 109 control low control Buffer vessels rm signal status unit 7 Emergency supply facility 8 Sys 8 1 General 8 9 Cylinder manifold supply systems 8 11 Compressor supply systems 8 13 Operating and alarm system 8 13 Cylinder manifold supply system 8 13 Manifold monitoring and indicator system 8 14 Manifold monitoring 8 15 Manifold indicator unit 8 16 Alarm signal stat
107. al apparatus for explosive gas BSI 60079 14 atmospheres Electrical installations in Standards hazardous areas other than mines BS EN 60529 Specifications for degrees of BSI protection provided by enclosures IP Standards Version 2 0 June 2001 Page 261 of 264 Borders General Hospital NHS Trust on behalf of NHSScotland Property and Environment Forum SHTM 2022 Part 1 Medical gas pipeline systems Medical electrical equipment General requirements for safety BS EN 60898 Specification for circuit breakers for over current protection for household and similar installations BS EN 60947 Specification for low voltage BS EN 60947 2 BS EN ISO 9000 BS ISO 11195 switchgear and controlgear Circuit breakers Quality management and quality assurance standards Gas mixers for medical use stand alone gas mixers Scottish Health Technical Guidance SHTM 2007 SHTM 2011 SHTM 2014 SHTM 2015 SHTM 2022 SHTM 2025 SHGN SHPN 1 SHPN 2 SHTN 1 SHTN 4 Electrical services supply and distribu Emergency electrical services Abatement of electrical in Bedhead services Medical gas pipelin missioning documentation for dings in Scotland S in Scotland PROCODE NHS in Scotland Firecode SHTM 81 SHTM 82 SHTM 83 SHTM 84 SHTM 85 SHTM 86 SHTM 87 Fire precautions in new hospitals Alarm and detection systems Fire safety in healthcare premises general fire precautions Fire safety i
108. alarm system Where relays are used they should be normally energised relays which de energise under fault conditions with contacts having a minimum rating of 50 V dc 50 mA Alternatively volt free normally closed contacts rated at 50 V dc 50 mA should be provided for transmission of conditions b to e to the alarm system The panel can be incorporated into the VIE control unit within the VIE compound or be a separate unit within the enclosure If mounted separately the cabling should be monitored for open short circuit In the event of such a cabling fault a red system fault lamp should be illuminated on the alarm signal status unit together with the appropriate alarm condition Liquid oxygen supplies from cylinder General Traditionally piped medical oxygen ha cylinder manifolds or VIEs dependin storage requirements The introduvy provides greater flexibility of storag between the smaller compres substantial bulk liquid v S n S pplied from compressed gas xygen usage rate and supply by liquid cylinders r mid range gas volumes ifold capacities and the more The advantages of medal oxyg n liquid cylinders are increased hf J efficiency labour savingWr the hospital environment greater urity of supply and stock holding D Q2 2 ODW 3 x O reduced manifold and cylinder space A typical installation is shown in Figure 8 Due to increasing oxygen consumption the use of telemetry
109. alf of NHSScotland Property and Environment Forum Free air flow l min 3000 2500 2000 1500 1000 500 Appendix 9 SHTM 2022 Part 1 Medical gas pipeline systems Pressure loss data 400 kPa 22mm 22mm Pressure loss 7kPa l 14kPa A 22mm 21kPa x 15mm 15mm mm p 12mm 12mm r 0 25 1 1 25 1 5 1 75 2 25 2 5 2 75 Pressure drop kPa m Version 2 0 June 2001 Page 248 of 264 Borders General Hospital NHS Trust on behalf of NHSScotland Property and Environment Forum Free air flow l min SHTM 2022 Part 1 Medical gas pipeline systems Pressure loss data
110. an on auto selector switch individually fused separate cycling systems for each sieve pair a system to control regeneration of the sieves in relation to pipeline demand an oxygen concentration dryness sensor and a pressure sensor an automatic changeover to the standby molecular sieve system in the event of failure of the duty unit by oxygen concentration dryness or pressure This requires i electrical and pneumatic isolation of the duty sub assembly so that it is taken off stream ii electrical and pneumatic energisation of rie standby sub assembly so that it is brought on stream lil activation of the appropriate fault in to sociated volt free contacts iv the sub assembly to remain has been rectified is of operation until the fault green function indicators r e er sub assembly to indicate i molecular sieve C ii molecular sieve 2 seleciqd lil selected g normal iv selecte ar sieve failed this fault indicator should remain until ma reset by means of a reset button a fail closure hich on failure of the power supply causes the Inet Outlet exhaust and purge valves Plant status Monitoring A monitoring system must be provided to detect the following faults in the air compressor system a plant faults for each compressor i control circuit failed ii overload tripped ili after cooler temperature high
111. and Property and Environment Forum 15 16 15 17 15 18 15 19 15 20 SHTM 2022 Part 1 Medical gas pipeline systems contamination should be carried out with medical air and the system then left under pressure Tests before use The following tests must be carried out after purging and filling with the working gas test for particulate contamination test for gas identities tests for gas quality a 9 5 p checks of the labelling of AVSUs to include gas label flow direction arrow and area served General requirements for testing General A physical break must always be used betwen exsting pipeline systems and any in use system and any systemefilled with purge gas This can be achieved either by deploying the spa es ing plates incorporated in area valve service units AVSUs or by nd capping the pipe Full size disc danger do not use prohibition labe be fitted to outlets taken out of service ho The tests described in must all be carried out in the order given for new installati s It may be necessary to modify the test programme slig ifi must be taken Paragraph 15 extension sure that the basic principles are followed ils of the tests required for modifications q systems forleakage is carried out in two stages for pressure gas irst pressure tests are applied to the pipeline carcass the second to theWwhole installation which may include terminal units and medical s
112. and Property and Environment Forum SHTM 2022 Part 1 Medical gas pipeline systems Medical gas Pipeline Carcass Tests Form B2 Sheet of Sheets Hospital Scheme File Number Date Cross Connection Test This is to certify that a CROSS CONNECTION test in accordance with paragraph 15 43 was carried out on the following medical gas pipeline systems No cross connections between these systems were found Contractor s representative Status Signed Date Name Version 2 0 June 2001 Page 221 of 264 Borders General Hospital NHS Trust on behalf of NHSScotland Property and Environment Forum SHTM 2022 Part 1 Medical gas pipeline systems Medical Gas Pipeline Total System Tests Form B3 Sheet of Sheets Hospital Scheme File Number Date Leakage Test from Total Compression Gas System This is to certify that a LEAKAGE test in accordance with paragraph 15 44 15 48 was carried out on the piped system on this scheme and that during the test a pressure of kPa was held for hours with a pressure drop of kPa Section Tested No of Hours Volume 2n h Pressure Pass Fail Terminal on of V Drop Units n Test h system found kPa ly E ave Contractor s Repre Status Signed Date Name Contract Supervig Officer Status Signed Date Name Witnessed on behalf of By Status Signed Date Version 2 0 June 2001 Page 222 of 264 Borders General Hospital NHS Trust on behalf of NHSScotland Property and Environmen
113. and as discussed above A typical system schematic is shown in Figu NOTE BS 6834 has been withdra Requirements BS EN 737 4 Ter Jal management part 2 of this SHTM The ude tests to ensure that the criteria for patient o remove pollution then consideration should be given ystem which complies with BS EN 737 BS EN 740 in terms of to installing Active and passive systems AGSS which comply with BS EN 737 BS EN 740 are active systems that is the air flow form the disposal system is as a result of a powered device such as a fan or suction unit Version 2 0 June 2001 Page 133 of 264 Borders General Hospital NHS Trust on behalf of NHSScotland Property and Environment Forum V S V D 3 Q Qa V Aa D 3 iS 3 N S3 A S AN I V Figure 14 Schematic diagram of AGSS BS 6834 has been withdrawn and is replaced by BS EN 737 2 Basic Requirements BS EN 737 4 Terminal Units and BS EN 740 Particular Requirements abieyosiq w s s jesodsip Jo s iwiy 9deJ19 UI JayOOS yun jeulw1a 3q01d w s s BUIAIDD9J JO SPUIT walsks 1T BulaLa DOY UOINOBUUNOD JUBSUBPWIS8_d uepu d 10 wooq aqIxa 4 J A UONOBUUOND JUBUBPWIS8 _d Voh y 0s pue qoud yun jeurwa L w S
114. and telemetry systems 6 26 Control panel 6 27 Sites for liquid oxygen storage 6 30 Operation 6 32 Standby system in use 6 35 Standby low 6 36 Low line pressure 6 37 High line pressur 6 39 VIE filling 6 40 Maintenance 6 42 6 45 storage vessel 6 48 ckup 6 50 essed gas cylinder backup 6 52 supply facility 6 9 signal status unit 6 62 Li yeen supplies from cylinders 6 6 General 6 65 W Liquid cylinder design 6 67 Liquid cylinder manifolds 6 69 Control panel 6 71 Emergency compressed oxygen manifold 6 72 Siting requirements 6 82 Liquid cylinder manifold sizing 6 84 Refilling 6 85 Alarm signal status unit 6 89 Oxygen concentrator installations PSA plant 6 89 General 6 94 Siting 6 98 Plant configuration Version 2 0 June 2001 Page5of 264 Borders General Hospital NHS Trust on behalf of NHSScotland Property and Environment Forum Version 2 0 June 2001 6 100 6 102 6 104 6 105 6 106 6 107 6 111 6 115 6 116 6 117 6 119 6 120 6 124 6 129 SHTM 2022 Part 1 Medical gas pipeline systems Compressors and vacuum pumps Compressor noise Molecular sieves Dryers Oxygen monitoring system Operating and indicating system Plant control unit Plant control indication Compressor and vacuum starter units Molecular sieve control unit Plant status monitoring Plant indicator unit Alarm signal status unit Plant management System design Medical air page 89 Compressor systems for 400 kPa m lica
115. anifold rooms emergency reserve manifold rooms for pressure swing adsorber PSA systems vacuum insulated evaporator VIE installations and medical compressed air systems should be located near to the medical gas cylinder storage area All manifolds including the emergency reser Ids may be located The emergency reserve manifold for ful systems has traditionally been located within the VIE comp it is preferable to site the manifold separately For new4nstal ese emergency reserve manifolds should be located s lt is preferable to site th manif medical air 700 kPa systems within the operating depar Howe er the gas used is at high flows but the overall consumpyen 1 nd therefore there may be little disadvantage i amote from the cylinder store The number of cylinders stored fh uildings should be kept to a minimum The medic al a manifold room may be used as the ready use store for a small r nber of spare cylinders to be used on anaesthetic machines Access Access to manifold rooms should be from the open air not from corridors or other rooms Normal commercial lorry access is suitable for gas cylinder delivery vehicles but consideration should be given to the provision of a raised level loading bay when this is justified economically on the basis of cylinder handling costs Two doors should preferably be provided in a manifold room One should be large enough to facilitate cylinder handling and must be in an out
116. are shown in Figure 9 The typical major components of the system are the compressors receiver dryers molecular sieves vacuum pumps filters and regulators Other components are identical to those used for medical air and vacuum plant which are described fully in the appropriate sections A suitable Version 2 0 June 2001 Page 79 of 264 Borders General Hospital NHS Trust on behalf of NHSScotland Property and Environment Forum 6 94 6 95 6 96 6 97 SHTM 2022 Part 1 Medical gas pipeline systems operating and indicating system is also required as specified below Package supply systems which should be specified to meet the requirements given in this memorandum are available from manufacturers Siting The plant should have all round access for maintenance purposes and allowance should be made for changing major components The siting of the plant should allow for adequate flows of air for three different purposes a air intake to the compressors b cooling of the compressed air by the after coolers c cooling of the compressors quate flow of cool of operating circumstances Each compressor may require ducting to ensu ply with BS ISO 5011 2000 and aper element filters Version 2 0 June 2001 Page 80 of 264 Borders General Hospital NHS Trust on behalf of NHSScotland Property and Environment Forum Page 81 of 264
117. articulate material which may be present in the pipeline The terminal units to be sampled should be in accordance with paragraph 15 91 Filter holders appropriate to the pressure encountexed are commercially available The filter holder should be specified for use and be oxygen compatible Measurement principle A known volume of gas is passed thr yugh a membrane filter which will collect all visible particles nge of pore sizes A maximum pore size of 10 um will colled all visio material Pore sizes below 0 2 um are likely to restrict fl Oneeine destribution pressure The QC shoul condition of the filter which should be free from visible pa The following quipment is required a membrane filter holder b asupply of white membrane filters of not more than 10 um pore size and with high mechanical strength a means of connecting the filter to the pipeline a means of controlling the flow through the filter which is connected downstream of the filter One method of achieving this is to use the appropriate Amal jets to achieve a minimum flow of 150 l min at 400 kPa and 700 kPa e all equipment must be oxygen compatible and hoses should be anti Static Version 2 0 June 2001 Page 240 of 264 Borders General Hospital NHS Trust on behalf of NHSScotland Property and Environment Forum SHTM 2022 Part 1 Medical gas pipeline systems Procedure The following procedure should be carried out a p
118. be performed for main service valves Cross connection Each system in turn including vacuum must be checked as follows to ensure that there is no cross connection between pipelines for different gases and vacuum installations are utian system must be ipeline distribution sphevic pressure A check very terminal unit of the there is no gas flow through any Cross connection tests should not commence complete All AVSUs and any other valve in open on all systems The system under test pressure and all other systems must b pat at must be made to ensure that gas flo system under test one at a time d other terminal units The test must be repeate preferably at one sessi e system in turn including vacuum There must be no sonne n This test must to the pipeline sy in full if any subsequent modifications are made drop at terminal units Jrop must not exceed the values in Table 1 of BS 5682 1998 1992 as amended but see also Table 23 for surgical air systems and oxygen carbon dioxide when each terminal unit is tested one at a time using the appropriate device described in Appendix 3 at its specified flow with the pipeline at pipeline distribution pressure Mechanical function of terminal units lt must be demonstrated for each terminal unit that the appropriate gas specific probe can be inserted captured and released and that the probe does not swivel in any horizontally mount
119. between 2 0 and 8 ppm nitric oxide and 0 2 to 0 5 ppm nitrogen dioxide were recorded With scavenging the maximum levels were respectively 0 2 ppm and a nil value for nitrogen dioxide On this evidence the provision of waste gas scavenging does not appear to be an occupational hygiene priority although if otherwise available staff may wish to use an existing system Standard AGSS components and materials are satisfactory Chemical adsorption filters are possible but their availability is limited and taking into account the relative risk may introduce a greater problem of disposal Version 2 0 June 2001 Page 144 of 264 Borders General Hospital NHS Trust on behalf of NHSScotland Property and Environment Forum SHTM 2022 Part 1 Medical gas pipeline systems Validation and verification 11 38 Pressure testing and purging should be carried out in accordance with Validation and verification except that argon should be used for this stage 11 39 On satisfactory completion of all purging the system should be filled with the working gas and all terminal units should be checked for gas identity Quality tests should be performed using argon prior to this stage Version 2 0 June 2001 Page 145 of 264 Borders General Hospital NHS Trust on behalf of NHSScotland Property and Environment Forum 12 1 12 2 12 3 12 4 12 5 12 6 12 7 SHTM 2022 Part 1 Medical gas pipeline systems 12 Warnin
120. brushing with stainless steel type wire brush The oxides formed should be remov acid solution at 65 C nominal to wh dichromate has been added The nt should then be thoroughly rinsed in hot water at 80 C namin ould result in a bright clean component mrsing in a 5 10 sulphuric The fitting should be de jrease Purging with th Purging should ut strictly in accordance with the procedures given in d verification Pipe supp The pipeline snould be adequately supported at sufficient intervals in accordance with Table 21 to prevent sagging or distortion Supports for surface mounted pipework should provide clearance to permit painting of the surface Where it is essential for pipes to cross electric cables or conduit they should be supported at intervals on either side of the crossing to prevent them from touching the cables or conduit Supports should be of suitable material or suitably treated to minimise corrosion and prevent electrolytic reaction between pipes and supports Version 2 0 June 2001 Page 167 of 264 Borders General Hospital NHS Trust on behalf of NHSScotland Property and Environment Forum 13 47 13 48 13 49 13 50 13 51 SHTM 2022 Part 1 Medical gas pipeline systems Table 21 Intervals between copper pipe supports Outside dia mm Maximum interval for vertical Maximum interval for runs m horizontal runs m 12 1 2 1 0 15 1 8 1 2 22 2 4 1 8 28 2 4 1 8 35 3 0 2 4 42 3 0 2 4
121. by comparison with a central system The area alarm panels carry no indication of the warnings for cylinder replacement and plant function which are given on central systems Version 2 0 June 2001 Page 150 of 264 Borders General Hospital NHS Trust on behalf of NHSScotland Property and Environment Forum Y S V D 3 Q Qa V Aa D 3 iS 3 N S3 A S AN I V Figure 18 Signal path for typical plant reproduced by kind permission of Shire Controls t or INe ounssaid LINN TIOHLNOOD LINQ TOYLNOD Hne nss id iS ne ssau4q YAAYC EUERE YAAYC ne ssoufug G 0 O Aa a LINN ddLyvL LINN HALYVLS HOSSJHYdNWOOD uossgydhon GOES aan YOSSAYdWOO paddy peoyaaO p dd peojyaaO Bawa uel l yBiy ounyesodwa jinn LINN yBiy aunyesodwa JOSSesdWwo0D AOYLNOD LNW1d JOULNOO JOSSEJGWOD y iy sunyesodwe INVW1d y iy sinyesodwe J9 009 JOUVY J9 009 JOUVY peddii peojiaAO p dd peojsaAO p jre sossaidwoy gjle JOSSBIGWOD Pgfley N9119 OAUOD P9fley N9119 OAUOD T T Y N eb S LINN YOLYOIQNI Ne LNA SNLVLS N LINN YOLVOIGNI a gt SNLVLS LNV1d JUe d IWNOSIS WHV IV JUe d SNLVLS LNV1d a 2 S eine MO ney SWS SJapul AD M S Y ainssaid auljadid ANI lddld w s s wee oj
122. cal vacuum supplies General The medical vacuum pipeline system provides immediate and reliable suction for medical needs particularly in operating theatres The medical vacuum pipeline system consists of the vacuum supply system the distribution pipework and terminal units The performance of the pipeline system is dependent on the correct specification and installation of its component parts This section describes the requirements of the vacuum supply system The medical vacuum pipeline system should be vacuum of at least 300 mm Hg 40 kPa at ea system design flow tests see Appendix 7 Signed to maintain a al unit during the To ensure continuity of supply the va t should be connected to the essential electrical power supply pl hould be appropriate to the estimated demand Observat pacity actually used in terms of hours run by vacuum pl i ing systems show clearly that the system in capacity may be undertaken in an existing hospital cuum supply system based on the design criteria in Chapi en replacement is due This could lead to With the ex ion of the vacuum discharge to atmosphere the pipeline distribution system for vacuum has traditionally been constructed of copper PVC pipework can be considered where cost effective Pressure testing of PVC pipework should be carried out at 100 kPa The major components of a medical vacuum system and their layout are shown in Figure 13 A suitable operating and
123. construction should provi ion of functional extra low voltage FELV electrical service of flexible partitions or conduit as appropriate Access to five co nts should be via panels which are ment to rigid pipework or terminal units should be by mes AOpropriate non interchangeable screw thread NIST connector Version 2 0 June 2001 Page 169 of 264 Borders General Hospital NHS Trust on behalf of NHSScotland Property and Environment Forum SHTM 2022 Part 1 Medical gas pipeline systems Figure 19 Colour code identification for medical gas terminal outlets and pipe installations Notes 1 Base colours are as follows A yellow ochre 08035 B light blue 20E51 2 All colours in this diagram should be taken to be representative rather than exactly accurate 3 Reference numbers in colour codes conform to BS 4800 1972 Version 2 0 June 2001 A 00E55 WHITE A 20D45 FRENCH BLUE 00E55 20D45 FRENCH GREY 12B21 BLACK 00E53 PRIMROSE 10E53 A GREEN 14E53 20D45 10E53 B BLACK 00E53 Borders General Hospital NHS Trust on behalf of NHSScotland Property and Environment Forum N O O NO 50 mixture 0 CO CO lt 5 Medical air Medical vacuum NO nitric oxide Proposed AGSS Colour code identification for medical gas terminal outlets and pipe installations Page 170 of 264 13 57 13 58 13 59 13 60 13 61 13 62 13
124. continuous on all central and repeater panels Operation of the continuous mute should inhibit the 15 minute reinstatement of the audible alarm Version 2 0 June 2001 Page 156 of 264 Borders General Hospital NHS Trust on behalf of NHSScotland Property and Environment Forum 12 52 12 53 12 54 12 55 12 56 12 57 12 58 12 59 12 60 12 61 SHTM 2022 Part 1 Medical gas pipeline systems Operation of the mute should not inhibit the visual or audible indication of any subsequent alarm conditions Panel legend and display Panel legend and display should be as shown in Table 19 Repeater indicator panel requirements Displays The repeater indicator panel should always display normal emergency alarm and alarm system fault conditions as given above The repeater panel should display some or all of the warning conditions which are displayed on the central indicator panel as given in paragraph 12 49 The extent of the display of warnings should be variegxo suit local clinical requirements Mute functions ignal for about 15 minutes h Op ration of the temporary e visual indicator to continuous The temporary mute should cancel t whilst the visual indicator continu mute on the central panel should illumination au g st inhibit the 15 minute reinstatement Operation of the continyus mut of the audible alarm ho ot inhibit the visual or audible
125. contractors Validation and verification The objective of validation and verification is t6 en that all the necessary safety and performance requirements of the MGS wil met Validation and verification procedures will be required fone allations additions to existing installations and modificatio isting installations The scope of work will dictate the specific progr This is described in more detail in Chapter 3 Provision of te requ ina its General fire preca The siting and rey ctural principles for the design of liquid oxygen storage accommewation are given in Chapter 4 Liquid oxygen supplies and VIEs and ments for plantrooms and gas manifold rooms in Chapter 1 odation General Guidance on ylinder storage and handling is given in the Operational management part 2 of this SHTM Fire detection system smoke or heat detector heads should be installed in the plantrooms medical gases manifold rooms and when internal medical gases cylinder stores in any hospital having a fire detection system in accordance with NHS in Scotland Firecode SHTM 82 Alarm and detection systems Electricity supply to medical gas installations General The whole of the electrical installation should be carried out in accordance with the extant edition of the IEE Regulations for Electrical Installations Version 2 0 June 2001 Page 20 of 264 Borders General Hospital NHS Trust
126. cotland Property and Environment Forum 6 81 6 82 6 83 6 84 6 85 6 86 SHTM 2022 Part 1 Medical gas pipeline systems For further guidance on liquid cylinder location refer to BS EN 1251 3 2000 Cryogenic vessels transportable vacuum insulated of not more than 1000 litre volume operational requirements and the BOC Guidance Notes Form G4521 Liquid cylinder manifold sizing The manifold will be sized according to the average annual usage with liquid cylinder installations being ideally suited to annual consumptions of between 3000 and 40 000 Nm per annum As the lower end of the medical VIE range reflects a minimum annual usage of approximately 27 500 Nm per annum there is an overlap of annual consumption between 27 500 Nm and 40 000 Nm per annum where either a bulk VIE or a liquid cylinder installation could be considered to satisfy a particular requirement or accommodate possible site restrictions approximately 24 J sized cylinders NOTE One 200 litre liquid cylinder LC200 KA e capacity equal to Refilling Refilling of liquid cylinders is carrie analysis and certification of t with a fill header which en itu including pre and post e cylinder manifold is equipped illing of multiple cylinders in situ Alarm signal status uit AY Ovection of manifold conditions should be provided The alarm signe e same as for VIE systems The following in Indication Legend
127. coupling comprises two joints gt 1oints For modif should be with an inert gas shield to avoid widespread oxide contaminatiG 7 and thus it is essential that a physical break is employed between the feline being modified and any in use systems and prohibition labels are affixed to outlets in areas occupied by patients and that all the identity purity and quality tests are carried out On a minor modification from which existing terminal units would not be removed it may not be practical to carry out a pressure test on the new carcass and therefore this could be deleted All other tests would be required including the pipeline pressure test The programme of tests is divided into three phases a tests and checks on the pipeline carcass b tests and commissioning of the complete pipeline system with terminal units installed for safety performance and particulate contamination using test gas c filling of the systems with specific gases quality tests and proof of the identity of those specific gases prior to use for patient care Version 2 0 June 2001 Page 180 of 264 Borders General Hospital NHS Trust on behalf of NHSScotland Property and Environment Forum 15 8 15 9 SHTM 2022 Part 1 Medical gas pipeline systems The basic rationale for the tests is depicted as a decision tree in Figure 20 The personnel and test equipment needed for these tests are listed together with the test requirements in Table 2
128. d then each terminal unit should be capable of passing 350 l min Where several terminal units are provided it is unlikely that more than one terminal unit will be in use at any time and therefore the total design flow for the equipment service workshop will be 350 l min Because the actual use will be low it is unlikely that the provision of such a terminal unit for testing purposes will have a significant effect on the total design flow for the surgical air 700 kPa system Version 2 0 June 2001 Page 48 of 264 Borders General Hospital NHS Trust on behalf of NHSScotland Property and Environment Forum 4 71 4 12 4 13 4 14 4 75 4 76 4 4 78 4 79 4 80 4 81 SHTM 2022 Part 1 Medical gas pipeline systems Vacuum In patient accommodation Where vacuum terminal units are provided in ward areas it is unlikely that more than one terminal unit in any room single or multi bed will be in use at any time Therefore the diversified flow QW should be calculated on the basis of 40 I min per ward unit of 28 beds although each terminal unit should be capable of passing 40 l min For a department comprising several ward areas and treatment rooms the diversified flow is based on 80 l min for the first bed and 1 l min for the remainder For treatment rooms 40 l min should be allowed for the first room and it may be assumed that no more than 25 of the remainder will be in use simultaneously see Table 13
129. d 14 21 bar at the end of the test assuming that no leakage has occurred x Version 2 0 June 2001 Page 237 of 264 Borders General Hospital NHS Trust on behalf of NHSScotland Property and Environment Forum 10 SHTM 2022 Part 1 Medical gas pipeline systems Appendix 3 Pressure drop test device General Special test devices are required to measure the pressure at specified flows at each terminal unit Suitable test devices are commercially available or may be constructed in accordance with the outline specification given below Measurement principle Flow at a specified pressure may be measureg eith ith a calibrated orifice or with a flowmeter Pressure may be measured with a bo ga A gas specific probe conforming t BSN682 should be used to connect the device to the terminal unit The test device is conne and the pressure at the O ecifie terminal unit by the gas specific probe is read on the gauge Functional requi The test devic ist of the following components to BS 5682 ptional on off valve D Q wi D ro O oo Oo Q 0 8 o lt G a C qD uge orifice or flowmeter The body may be of a design which allows exchange of the following components a gas specific probes b calibrated orifices C pressure gauges An on off valve may be incorporated into the body The complete assembly should be tested for leaks Version 2 0 June 2001 P
130. d in a common panel and located on the plant or on the plantroom wall Control panels containing pneumatic components should have vents to permit release of pressure in the event of component failure All functions and indicators should be appropriately identified and should have a design life of at least five years The operating system should be capable of automatically restarting after reinstatement of the power supply All components of the PSA supply system should be connected to the standby electrical supply The control system should ensure that compressors restart in sequence to avoid overloading the essential power supply Version 2 0 June 2001 Page 83 of 264 Borders General Hospital NHS Trust on behalf of NHSScotland Property and Environment Forum SHTM 2022 Part 1 Medical gas pipeline systems Plant control unit 6 111 The plant control unit should have a separate power supply for each compressor and vacuum pump controlled by a separate sub circuit The design should be such that no single component failure in the control unit will result in loss of plant output 6 112 The unit should allow either manual selection of duty standby for each of the compressors or have an automatic sequence selection with a means for manual override The unit should ensure that two or more compressors do not start simultaneously when power is applied 6 113 A warning notice which complies with BS 5378 should be affixed which indicate
131. d other detachable components should withstand steam Sterilization at 184 3 0 C The manufacturer should recommend methods of cleaning disinfecting and sterilizing the system and the manufacturer s recommendations should be followed The fixed pipework may be of copper or other suitable material such as PVC Where copper pipework is installed at the same time as the MGPS it is desirable to use degreased pipework to the same specification as that used for the MGPS see Chapter 13 in order to avoid confusion Version 2 0 June 2001 Page 136 of 264 Borders General Hospital NHS Trust on behalf of NHSScotland Property and Environment Forum 10 45 10 46 10 47 10 48 SHTM 2022 Part 1 Medical gas pipeline systems Where PVC pipes larger than 38 mm diameter pass through a fire compartment they should be protected with metal sleeves extending for 1m either side of the compartment in accordance with the Building Scotland Regulations The requirements of NHS in Scotland Firecode and SHTM 81 should be followed Safety criteria The following safety criteria are specified in BS 6834 and all AGSS should comply with these criteria irrespective of whether they comply fully with the other requirements of the British Standard NOTE BS 6834 has been withdrawn and is replaced by BS EN 737 2 Basic Requirements BS EN 737 4 Terminal Units and BS EN 740 Particular Requirements Table 15 Safety criteria for
132. dge fuses for voltages up to and BSI 1988 including 1000 V a c and 1500 V d c Standards Part 2 2 Specification for fuses for use by authorised persons mainly for industrial application Additional requirements for fuses with fuse links for bolted connections Version 2 0 June 2001 Page 258 of 264 Borders General Hospital NHS Trust on behalf of NHSScotland Property and Environment Forum SHTM 2022 Part 1 Medical gas pipeline systems Direct acting indicating analogue BSI electrical measuring instruments and Standards their accessories Part 2 Specificaton for special requirements for ammeters and voltmeters Transportable gas containers valves BSI Standards Fire tests on building materials and BSI structures Non combustibility test for Standards materials BS 1710 Specification for identification of pipelines and services BS 2099 Specification for castors for hospital equipment BS 2718 Specification for gas cylinder trolle BS 3928 Method for sodium flame t filters other than for airgup engines and compresso BS 4272 i ines BSI ifi Standards fore to I C Standards BSI Standards BS 4322 BSI Standards BS 5169 USP icon for fusion welded steel BSI 2i receivers Standards BS 5045 BS 5378 afety signs and colours BSI Standards BS 5499 Fire safety signs and graphic symbols BSI Standards BS 5682 Specification for probes quick BSI connectors for use with m
133. dicator and the audible f check communication wiring faults betwe operate the system fault indicator and and repeater alarms check audible reinstatement for e h check that the audible can be col internal push button for gas s uted via operation of the rm condition only i check for correct identifi departmental or plan h as service on alarm panels and Verification of as fittef drawimys written in the expectation that this will happen In such circumstances the contract should require that the particulate contamination and odour tests specified in paragraphs 15 95 and 15 105 are carried out as an interim measure using medical air as the test gas Satisfactory completion of these particulate contamination and odour tests may then signify the completion of the construction contract NOTE With the exception of medical compressed air systems supplied from compressors medical compressed air cylinders should be used For nitric oxide systems oxygen free nitrogen cylinders should be used It is the responsibility of the client to ensure that proper provision is made in a specific contract for the maintenance integrity and any special connectors which may be required during this interim period Version 2 0 June 2001 Page 197 of 264 Borders General Hospital NHS Trust on behalf of NHSScotland Property and Environment Forum 15 81 15 82 15 83 15 84 15 85 15 86 15 87 15 88
134. e Figure 3 VIE with cylinder back up Figure 4 VIE with VIE standby Figure 5 VIE with liquid cylinder standby Version 2 0 June 2001 Page 60 of 264 Borders General Hospital NHS Trust on behalf of NHSScotland Property and Environment Forum 6 12 6 13 6 14 SHTM 2022 Part 1 Medical gas pipeline systems VIE A VIE installation comprises a avacuum insulated tank to store the bulk liquid at the appropriate operating pressure b a pressure raising system to maintain the VIE operating pressure c avaporiser system to convert the liquid into gaseous product at ambient temperature The control panel and instrumentation for the VIE are normally mounted centrally at the front of the vessel Pressure vessel details are given ona plate mounted on the outer vessel The vessel must be clearly labelled with the product name A separate ambient vaporiser system converts liquid into gas at the required working pressure of 10 5 bar A Version 2 0 June 2001 Page 61 of 264 Borders General Hospital NHS Trust on behalf of NHSScotland Property and Environment Forum SHTM 2022 Part 1 Medical gas pipeline systems Figure 3 Typical VIE layout and pipework configuration with cylinder backup reproduced by kind permission of BOC TO CUSTOMER PA PRESSURE CONTROL PANEL 2 x 5 Res
135. e Note Similar values apply to other medical gases see relevant paragraph s in appropriate Ph Eur monograph Odour and moisture Odour The odour threshold of measurable particulate matter is approximately 0 3 mg m some elastomeric materials such as those commonly used in flexible hose may have a distinctive odour particularly when new Extensive tests have shown that the agents likely to be responsible for the odour are present only Version 2 0 June 2001 Page 17 of 264 Borders General Hospital NHS Trust on behalf of NHSScotland Property and Environment Forum 2 13 2 14 2 15 2 16 2 17 2 18 2 19 SHTM 2022 Part 1 Medical gas pipeline systems in minute parts per billion quantities and are considered to be of no toxicological significance Clearly the odour should not be nauseous Moisture similarly those elastomeric materials have been shown to desorb minute quantities of moisture into the gas stream The amounts of moisture are very small but on initial testing may result in moisture levels slightly in excess of 0 095 mg l These slightly raised levels of moisture may persist on initial testing for several months Extensive tests have shown that these slightly raised levels are of no consequence and reduce following purging with the working gas or use of the system Bacteria filters should be included in medical compressor systems to reduce the risk of delivering spores or other infectiou
136. e 2001 Page 22 of 264 Borders General Hospital NHS Trust on behalf of NHSScotland Property and Environment Forum SHTM 2022 Part 1 Medical gas pipeline systems Bed head trunking walling system These fittings should generally be in accordance with SHTM 2015 Bedhead services Separate compartments should be provided for electrical services nurse call radio etc and medical gas pipelines 2 50 Page 23 of 264 Version 2 0 June 2001 Borders General Hospital NHS Trust on behalf of NHSScotland Property and Environment Forum 3 1 3 2 3 3 3 4 3 9 3 6 SHTM 2022 Part 1 Medical gas pipeline systems 3 Provision of terminal units General A typical schedule of provision of terminal units is given in Table 2 Medical treatment policy is evolutionary and therefore the project team should review the requirements for individual schemes Terminal units should be mounted in positions which give the shortest practicable routes for flexible connecting assemblies between the terminal unit and apparatus Terminal units may be surface or flush mounted They may also be incorporated with electrical services nurse call systems and TV and radio audio services in proprietary fittings sug as bedhead trunking wall panel systems and theatre pendant fitting fer also to SHTM 2015 Bedhead services When planning the installation of theat operating luminaire and other ceiling no consideration When the
137. e 2001 Page 98 of 264 Borders General Hospital NHS Trust on behalf of NHSScotland Property and Environment Forum 7 63 7 64 7 65 7 66 7 67 SHTM 2022 Part 1 Medical gas pipeline systems A warning notice which complies with BS 5378 should be affixed which indicates the presence of low voltage Plant control indication There should be indicators for each compressor as follows green mains supply on b green compressor called for which indicates that the compressor motor is electrically energised c an indicator of the pressure produced by the compressor Compressor starter units There should be individual starter units for each compressor which operate a single designated compressor The starters shoulgybe provided with safety interlocks as specified by the compressor ma rs which should inhibit plant operation until manually reset b of a Sutton The starters should allow automatic restart after an interruUati starter unit should contain the following c an industrial grade a total hours cou e agreen mal control uni The dryer cQgtrol unit may be mounted on the dryers or may be located with unit There should be separate power supplies for the duty dryer assemblies taken from the same phase and standby The dryer control unit should contain the following a aduty dryer selector switch b aservice function to enable selection of continuous normal run
138. e made for ventilation and the required space to permit connection and disconnection of equipment should be considered The covers should be clearly labelled to indicated that medical gas equipment is installed within behind There are two possible alternative installation procedures a the connection between the pipeline and the trunking should be considered as first and second fix with the trunking being pre piped and certificated as complying with SHTM 2022 b the connection between the trunking and the pipework should be as paragraph 13 56 Version 2 0 June 2001 Page 171 of 264 Borders General Hospital NHS Trust on behalf of NHSScotland Property and Environment Forum 13 67 13 68 13 69 13 70 13 71 13 72 SHTM 2022 Part 1 Medical gas pipeline systems Shut off valves All valves should be of the lever ball type which open and close with a 90 turn Provision of valves Valves should be provided on items of plant and sources of supply to permit servicing and isolation of the main components and to connect the sources of supply to the pipeline distribution system Lockable line valves should be provided a atthe pipeline entry to a building b atthe pipeline exit from a building c on branches risers etc at the connection to the main pipeline All valves located outside the plantrooms wh ssible should be provided with lockable ventilated enclosure Area valve service units AV
139. e manifold serving a cryogenic oxygen system Compressed Reserve low Yellow No ABC cylinders on reserve manifold serving a compressor plant Pressure fault For each gas service Pressure fault Red Yes ABC pipeline High or to indicate that the low and oxygen pressure in the concentrator fault distribution system has for PSA risen fallen 20 from normal working pressure and oxygen concentration below 94 O Vacuum pressure To indicate that the Pressure fault Red Yes ABC pipeline vacuum in the pipeline serving the department has fallen 20 below the normal working vacuum Locations Version 2 0 June 2001 Page 159 of 264 Borders General Hospital NHS Trust on behalf of NHSScotland Property and Environment Forum SHTM 2022 Part 1 Medical gas pipeline systems A central panel telephone operator switchboard and or porters room 24 hour manned B facilities management office C theatre manager s desk special care baby unit and ITU nurses station D operating room For nitric oxide manifold alarm systems refer to Chapter 11 Table 20 Area alarm legend and display Alarm function Legend Colour Auditory signal For each gas service to indicate that the pressure in the pipeline High Red Yes serving the department has risen 20 above normal working pressure pressure For each gas service to indicate that the pressure in the pipeline Ow Red Yes serving the department has fallen 20 below normal working ressure p
140. e pollution from the vicinity of the dental chair where relative analgesia is used These may be effective in reducing the resultant environmental pollution In obstetrics local exhaust ventilation systems hoods and other extract systems have not been shown to be effective in removing the pollution in delivery areas where 50 nitrous oxide 50 oxygen is used as an analgesic In this case the pollution should be minimised by good room ventilation and good housekeeping techniques Version 2 0 June 2001 Page 132 of 264 Borders General Hospital NHS Trust on behalf of NHSScotland Property and Environment Forum 10 30 10 31 10 32 10 33 10 34 10 35 SHTM 2022 Part 1 Medical gas pipeline systems In recovery areas the major source of pollution is the patients expired gases Local exhaust systems or proximity devices have not been found to be effective because of the need for excessively high extract flows and close positioning of the device to the patient which may interfere with effective nursing In recovery areas good room ventilation should be provided Scottish Health Technical Memorandum 2025 Ventilation in healthcare premises gives further information AGSS design General For new installations an AGSS which complies with the requirements of BS EN 737 and BS EN 740 should be installed in all operating departments and other areas as required in accordance with the level of provision set out in Table 2
141. e stable o Alarm signal status unit The same alarm conditions for liqui should also be transmitted and displayed for the liquid nitrog he following conditions should be displayed for the mixing Indication Legend a green nor normal b yellow pl low gas pressure to any mixer c yello nt rgency analysis out of specification on any mixer d yellow Veserve low operating on final mixing panel buffer vessel only e red pressure fault pressure fault Conditions b to e should be transmitted to the central alarm system Where relays are used they should be normally energised relays which de energise under fault conditions with contacts having a minimum rating of 50 V dc 50 mA Alternatively volt free normally closed contacts rated at 50 V dc 50 mA should be provided for transmission of conditions b to e to the alarm system The panel can be incorporated into the mixing panel control unit or be a separate unit within the plantroom If mounted separately the cabling should be monitored for open short circuit In the event of such a cabling fault a red Version 2 0 June 2001 Page 110 of 264 Borders General Hospital NHS Trust on behalf of NHSScotland Property and Environment Forum SHTM 2022 Part 1 Medical gas pipeline systems system fault lamp should be illuminated on the alarm signal status unit together with the appropriate alarm condition Emergency supply facility 7 128
142. e system with the supply system disconnected so that gas cannot be supplied to the pipeline from the supply system For the purpose of this test the supply system extends to the last valve s detailed on the appropriate schematic drawing This point should be identified on the contract drawings A leakage of not more than 0 02 I hour is permitted from each terminal unit The system must be tested at pipeline distribution pressure After a period under test a pressure drop may be observed in the system The pressure drop must not exceed the value calculated from formula 2n h P y where p gauge pressure drop in k N n number of terminal u h number of hours st WRetween 2 and 24 V volumetric cap es of the pipeline system at atmospheric pressure The following be noted see Appendix 2 c where leakage is in excess of the specified limits the source of the leak must be identified and the fault rectified d the volume of the system may be measured by the procedure given in Appendix 8 Leakage into total vacuum systems Prior to testing the vacuum plant should be operated to remove any condensation in the system With the system at pipeline distribution pressure and with the source isolated the pressure increase in the pipeline must not exceed 10 mmHg after 1 hour There is no additional allowance for temperature correction in this test Version 2 0 June 2001 Page 190 of 264 Borders General Hos
143. e undertaken by contractors who are registered to BS EN ISO 9000 with their scope of registration defined to include commissioning All relevant tests should be carried out by the persons listed in Table 22 and witnessed by the appropriate persons who must record the results of the tests in writing for the hospital authority Summary of tests Tests and checks on the pipeline carcas The following tests must be carried ou carcass but before concealment r invtallation of the pipeline a visual check of pipeline labellin ar Sleeving and support b leakage test c documented tests fdr cross cormection zonin y and leakage b tests of area valve service units AVSUs for closure zoning and correct control of the terminal units involved c tests for cross connection flow pressure drop mechanical function and gas specificity of the terminal units and for cross connection mechanical function and gas specificity of NIST connectors d performance tests of the pipeline system e functional tests of all supply systems f inspection of safety valve certification g tests of warning systems h tests for particulate contamination These tests may be carried out with either medical air or after purging and filling with the specified gas If the system is not to be taken into immediate use the tests for particulate Version 2 0 June 2001 Page 184 of 264 Borders General Hospital NHS Trust on behalf of NHSScotl
144. eady illumination of the corresponding visual indicator on the central panel only Operation of the mute on area alarm or repeater panels should not be accompanied by a change from flashing to steady illumination Continuous muting An internally mounted switch should be provided to allow continuous muting during periods of maintenance When the system condition returns to normal the continuous muting should automatically reset to normal operation When the continuous muting is in operation on any alarm condition it should not prevent the operation of the audible signal on other alarm conditions when a fault condition arises Version 2 0 June 2001 Page 152 of 264 Borders General Hospital NHS Trust on behalf of NHSScotland Property and Environment Forum 12 21 12 22 12 23 12 24 12 25 12 26 12 27 12 28 12 29 12 30 SHTM 2022 Part 1 Medical gas pipeline systems Electrical wiring All electrical wiring should be in accordance with IEE regulations System integrity If extra low voltage ELV maximum 50 V is superimposed on the signal or communication circuit for example by cross connection the system design should ensure that any damage to the system is limited to replaceable panel components and that such damage is indicated as a system fault The performance of the system should not be compromised by the use of multi core cabling which carries ELV and communication signals in adjacent cores The
145. eatment Detailed guidance on compliance with COSHH is given in EL 96 33 and enclosure Advice on the Implementation of the Health amp Safety Commission s Occupational Exposure Standards or Anaesthetic Agents discharged It is therefore the respop wbi f the general manager or chief executive to implement the recur f the COSHH regulations with respect to anaesthetic g lons require that for every exposure to substances ealth the following should be carried out assessment of the risk b methods of achieving control of the risk c means of monitoring that the methods of control are maintained in an effective condition Both publications listed in paragraph 10 2 give details of the management actions which will need to be carried out in order to comply with the requirements of the COSHH regulations and are briefly covered in this chapter Version 2 0 June 2001 Page 129 of 264 Borders General Hospital NHS Trust on behalf of NHSScotland Property and Environment Forum 10 7 10 8 10 9 10 10 10 11 10 12 10 13 SHTM 2022 Part 1 Medical gas pipeline systems Effective control of exposure to anaesthetic gases will involve a combination of the following measures a the use of an effective scavenging system to remove the pollution at source b good room ventilation to dilute pollution from leaks patients expired air etc c good housekeeping to minimise leakage arising from poorly fitted
146. ed ball isolati shown in Figure 10 to allow dryers automatic drain be a valve on the com and the connectio Pressure indic Pressure equivalent ce if electronic indicators are used Calibration should be in bar g Pa All gauges should have a minimum scale length of 90 mm and the Yjorking range should not exceed 65 of the full scale range except on differential pressure gauges Where digital gauges are provided the height of the display should not be less than 14 mm Pressure indicators should be connected by means of gauge cocks Pressure indicators should be located on the plant control unit indicating receiver pressure on each receiver downstream of each pressure regulator on each dryer tower on the plantroom pipework downstream of the plant isolating valve 0229 5 wp on the test point Version 2 0 June 2001 Page 97 of 264 Borders General Hospital NHS Trust on behalf of NHSScotland Property and Environment Forum 7 99 7 96 7 9 7 7 58 7 959 7 60 7 61 7 62 SHTM 2022 Part 1 Medical gas pipeline systems Differential pressure indicators should be located on a each coalescing filter b each dust filter c each bacterial filter or any combination as appropriate All control devices should be connected directly to the pipework via a minimum leak device to allow removal for servicing and not isolated by valves Gauges should be isolated for maintenance
147. ed terminal units In vertically mounted terminal units the probe should be capable of twisting without undue force NOTE This test requires that the terminal unit is complete with its fascia in place Version 2 0 June 2001 Page 192 of 264 Borders General Hospital NHS Trust on behalf of NHSScotland Property and Environment Forum SHTM 2022 Part 1 Medical gas pipeline systems Gas specificity of terminal units 15 65 For each terminal unit it must be demonstrated that gas is released only when the correct probe is inserted that no probe is captured and that no gas is released when probes for all other gases are inserted All probes used for this test must be certified to BS 5682 1998 NIST connectors 15 66 For each NIST connector it must be demonstrated that normal flow of gas is achieved only when the correct NIST probe is inserted and mechanical connection made The NIST probes for all other gases must not make mechanical connection 15 67 lt must be demonstrated except for vacuum for each NIST connector that the self sealing device substantially reduces the flow of gas when the nut and nipple is removed NOTE It is not necessary to carry out these tes on factory connected NISTs which are incorporated into certified asSamb es Performance tests of the pipeline system 15 68 Each pipeline system in turn should b by introducing a number of calibrat at representative terminal uni thr test flow f
148. ed to identify th served In addition AVSUs should be labelled rooms etc controlled All valves and AVSUs arrows reas departments ify the individual w direction The AVSUs should be similarly label which pneumatic function is isolat l g which terminal units and ch AVSU b Pressure sensors function will need to be fitted to pipeline distribution sys ems In ll cases they should be installed in a location which is 2 lated and having access for maintenance in AVSUs Pressure sensors should be sment item They should be connected to the a minimum leak connector factory set anc pipeline bymean Pressure Pressure gaues are not usually required outside the plantroom of an MGPS If provided however they should similarly be installed in an adequately ventilated location They may be incorporated within AVSUs theatre supply fittings etc They should be installed with isolation cocks Test points Each supply plant that is liquid facility manifold compressor pressure swing adsorber PSA and blending plant should be provided with a test point comprising lockable valve and terminal unit for test purposes This should be within the plantroom or enclosure and be sited immediately upstream of the distribution pipeline isolating valve Version 2 0 June 2001 Page 174 of 264 Borders General Hospital NHS Trust on behalf of NHSScotland Property and Environment Forum 13 84 13 85 13 86 13 87
149. edical gas Standards pipeline systems Version 2 0 June 2001 Page 259 of 264 Borders General Hospital NHS Trust on behalf of NHSScotland Property and Environment Forum SHTM 2022 Part 1 Medical gas pipeline systems ID BS 5724 Medical electrical equipment BSI Part 1 General requirements for Standards safety Part 2 Particular requirements for safety Section 2 12 Specification for lung ventilators Section 2 13 Specification for anaesthetic machines BS 6281 Devices without moving parts for the BSI prevention of contamination of water Standards by backflow BS 6387 Specification for performance requirements for cables required to 4 maintain circuit integrity under fire conditions a BS 6651 Code of practice for protectie structures against lightni Standards BS 6759 Safety valves BSI Part 2 Specification f Standards valves for co Irs BS 7181 ificati i BSI 5001 actual i Standards for doz i BS 7671 BSI i yt l Standards sixte BS EN 132 Fe matory protective devices BSI tfinitions of terms and pictograms Standards BS EN 740 aesthetic workstations and their BSI odules Particular requirements Standards BS EN 737 1 Medical gas pipeline systems Terminal BSI units for compressed medical gases Standards and vacuum BS EN 737 2 Medical gas pipeline systems BSI Anaesthetic gas scavenging disposal Standards systems Basic requir
150. edical gas pipeline systems Contents 1 Scope page 15 1 1 Guidance in this document 1 6 Other guidance 1 7 Design installation and testing 2 General principles page 16 2 1 General statement 2 8 Quality requirements for medical gases and air 2 11 Odour and moisture 2 11 Odour 2 13 Moisture 2 16 Pipeline distribution system design 2 19 Safety 2 24 Installation supply of equipment maifte 2 29 Modifications 2 28 Removal of pipework 2 29 Validation and verification 2 30 General fire precautions 2 30 General 2 32 Fire det S 2 33 Electricity suppif to med as installations 2 33 2 40 2 42 Stme ot electrical cables 2 4 cal wiring in plantrooms 2 49 Elg ly pendants 2 4 Ceiling pendant fittings rigid multi purpose type 2 50 Bed head trunking walling system 3 Provision of terminal units page 24 3 1 General 3 18 Terminal units for nitric oxide oxygen carbon dioxide mixture 3 19 Nitrogen for surgical tools 4 Gas flow page 35 4 1 General 4 10 Gas flow 4 10 Terminal unit flows 4 13 Pipeline flows Version2 0 June2001 i ststi OW lt S SsSSS age 8 Of 264 Borders General Hospital NHS Trust on behalf of NHSScotland Property and Environment Forum SHTM 2022 Part 1 Medical gas pipeline systems 4 21 Oxygen 4 21 In patient accommodation 4 2 Hyperbaric oxygen chambers 4 28 Operating departments 4 32 Intensive therapy and coronary care units 4 36 Maternity 4 40 Nitrous oxide
151. edical gas pipeline systems Form B9 Sheet of Sheets Scheme Date This is to certify that the following sources of supply have been tested according to paragraphs 15 72 15 73 and the attached sheets and found to comply with the specification Source of supply Manifold Manifold Manifold Name Signature Liquid Oxygen Plant Air Compressor Vacuum Plant Oxygen Concentrator 4 x Witnessed on behalf of By Signed Version 2 0 June 2001 Contractor s Representative N i yy Contract Supervising Officer Name Signature x x Status Date Page 229 of 264 Borders General Hospital NHS Trust on behalf of NHSScotland Property and Environment Forum SHTM 2022 Part 1 Medical gas pipeline systems Medical Gas Pipeline Total System Tests Form B10 Sheet of Sheets Hospital Scheme File Number Date Pressure Safety Valves The pressure safety valves fitted to the pipeline systems have been inspected together with their certification and are in accordance with the contract specification and paragraphs 15 74 15 75 Location Valve Position Pipeline Certified B A Number Distrib Discharge Pressure A Pressure B lf certificates are not provided do not Contractor s Representative Status Date Contract Supe Status Date Witnessed on behalf of By Status Signed Date Version 2 0
152. el requirements 12 49 Displays 12 50 Mute functions 12 53 Panel legend and display 12 54 Repeater indicator panel requiremen 12 54 Displays 12 55 Mute functions 12 58 Panel legend and A 12 59 Area warning and alagm pa 12 59 Displays 12 60 Mute fuggtions 12 62 Panel l gend arg display 12 63 L 13 Pipelin a n page 161 13 1 A odeaion of pipes 13 9 Pi rials 13 1 Quality 13 1 Pipes 13 14 Other fittings 13 15 Cleaning 13 15 Pipes 13 16 Pipe joining fittings 13 18 Pipeline jointing 13 18 General 13 27 Jointing methods 13 30 Pipe preparation 13 31 Use of N2 internal inert gas shield 13 31 Application 13 33 Safety Version 2 0 June 2001 Page 10 Of 264 Borders General Hospital NHS Trust on behalf of NHSScotland Property and Environment Forum 14 14 1 14 11 14 14 14 22 14 23 15 19 1 15 14 Version 2 0 June 2001 SHTM 2022 Part 1 Medical gas pipeline systems 13 34 Control cylinders 13 35 Other installation processes 13 36 Inspection of joins 13 37 Internal cleanliness 13 38 Penetration 13 39 Capping 13 40 Removal of flux residues and oxides 13 45 Purging with the working gas 13 46 Pipe supports 13 52 Identification of pipelines 13 54 Pipeline fittings 13 54 General 13 55 Ceiling pendant fittings rigid multi purpose type 13 61 Flexible pendant fitting 13 62 Bed head trunking walling syst 13 67 Shut off valves 13 68 Provision of valves 13 70 Area valve service uni VSUs 13 75 Provision of AVSUs
153. em ac on The panel can be incorporate nt status indicator unit or be a Ma the event of such a cabling fault a red inated on the alarm signal status unit should be supplied from all individual plant separate common supply Connections should be provided which allow monitoring but not control of plant alarm conditions b to e and pump running for each compressor These connections should be volt free contacts normally closed for each condition having a minimum rating of 50 V dc 50 mA The building management system should not be used to control the plant Operating considerations Plant should be operated in accordance with the manufacturer s instructions and covered by a sound effective planned preventative maintenance PPM policy Version 2 0 June 2001 Page 116 of 264 Borders General Hospital NHS Trust on behalf of NHSScotland Property and Environment Forum SHTM 2022 Part 1 Medical gas pipeline systems Simplex plant 8 32 The same philosophy should be applied to simplex plant as for medical air compressor plant except that no standby compressor dryer system or emergency reserve manifold or cylinders will be required Version 2 0 June 2001 Page 117 of 264 Borders General Hospital NHS Trust on behalf of NHSScotland Property and Environment Forum 9 1 9 2 9 3 9 4 9 5 9 6 9 7 9 8 SHTM 2022 Part 1 Medical gas pipeline systems 9 System design medi
154. em Since nitrous oxide is almost always administered via a breathing system an AGS terminal unit will be required in all areas where a nitrous oxide terminal unit is provided Details of the level of provision for AGS terminal units are given in Table 2 In general AGS terminal units should always be provided in areas where general anaesthetics are administered such as operating and anaesthetic rooms There may be other areas such as X ray and endoscopy departments where general anaesthetics are also administered on a regular basis and therefore consideration should be given to providing an AGS terminal unit in these areas This is indicated in Table 2 as a project team option The Ayres T piece and Jackson Rees open en used in paediatric anaesthesia It may not be these types of paediatric breathing system ventilation systems have not been shown to requirement for good room ventilatio reservoir bag are often ibe to use an AGSS with ned local exhaust eff and therefore the rly important IC Inhalation analgesia is used for p childbirth dentistry where the prac and reduction of anxiety during ally referred to as relative py ITU and acute wards using a oxide 50 oxygerx composition of administration is via a specially designed face exhales directly into the environment Considerable this way as an analgesic For dentistry local exhaust systems are currently being developed to remove th
155. ements BS EN 737 3 Medical gas pipeline systems BSI Pipelines for compressed medical Standards gases and vacuum Version 2 0 June 2001 Page 260 of 264 Borders General Hospital NHS Trust on behalf of NHSScotland Property and Environment Forum SHTM 2022 Part 1 Medical gas pipeline systems BS EN 737 4 Medical gas pipeline systems Terminal BSI units for anaesthetic gas scavenging Standards systems BS EN 837 1 Pressure gauges Bourdon tube BSI pressure gauges Dimensions Standards metrology requirements and testing BS EN 837 2 Pressure gauges Selection and BSI installation recommendations for Standards pressure gauges BS EN 837 3 Pressure gauges Diaphragm and BSI capsule pressure gauges Dimensions Standards metrology requirements and testing BS EN 850 Transportable gas cylinders Pin index yoke type valve outlet connections fo medical use BS EN 1044 Brazing Filler metals BS EN 1057 Standards BS EN 1089 i BSI 3 i i i i Standards BS EN 1251 BSI Standards BSI tings with ends for capillary Standards g or capillary brazing to copper BS EN 1254 C pper and copper alloys Plumbing BSI 2 fittings Fittings with compression Standards ends for use with copper tubes BS EN 1978 Copper and copper alloys Copper BSI cathodes Standards BS EN 1979 Copper and copper alloys Cast BSI unwrought copper products Standards BS EN Electric
156. en placed on low capital cost at the expense of reliability and high power costs The running costs should be calculated at realistic levels of usage d the control system for the compressor plant should include an hours run counter and should be constructed in accordance with the guidelines given below Version 2 0 June 2001 Page 92 of 264 Borders General Hospital NHS Trust on behalf of NHSScotland Property and Environment Forum 7 21 7 22 7 23 7 24 7 29 7 26 SHTM 2022 Part 1 Medical gas pipeline systems e the efficiency of plant expressed as the volume of air delivered to the pipeline distribution system after losses in the drying system per kilowatt hour should be stated by the supplier of the system The commissioning procedure should evaluate this efficiency by testing the power consumption over a suitable period of time at 100 10 and 0 of the system design flow A minimum efficiency of 5 m kWh at 100 and 10 is required The power consumption at zero flow should be less than 1 of that at 100 design flow After coolers After coolers and inter coolers usually form part of the compressor sub assembly After coolers should be fitted to oil lubricated medical air compressor systems but may not be required on water sealed screw compressors These will normally be air cooled and may need ducting with forced ventilation to ensure an adequate supply of gooling air Receiver
157. ention should be paid to the following a that all warning systems operate within the specified tolerance limits at all operating parameters and fault conditions and can be seen and heard as specified in Table 19 b that systems react correctly following return to normal status c that all panels and switches are correctly marked d that all warning functions on all stations operate correctly e that the warning system will operate from the essential supply standby power source Version 2 0 June 2001 Page 196 OF 264 Borders General Hospital NHS Trust on behalf of NHSScotland Property and Environment Forum 15 77 15 78 15 79 15 80 SHTM 2022 Part 1 Medical gas pipeline systems f that all systems are labelled to show the areas they serve or as detailed in the contract specifications The following tests should also be carried out a for central alarm panels check that the operation of the mute switch cancels the audible alarm and converts the flashing signals to steady b for repeater alarm panels check that the mute switch cancels the audible alarm and that the flashing signals are converted to steady only when the central alarm panel c for area alarm panels check that the operation of the mute switch cancels the audible only d check power failure operates red system fault indicator and audible e check that a contact line fault operates the system fault indicator the alarm in
158. erature does not exceed ambient temperature by more than 10 C In some cases it may be necessary to provide mechanical ventilation for plantrooms with supply air directed towards the compressor air intakes and inter after coolers It should rarely be necessary to provide cooling Manifold rooms may be used to store small numbers of nitrous oxide oxygen cylinders intended for portable use these are taken from the main cylinder store for the purpose of temperature equilibration before being delivered to wards etc To achieve temperature equilibration additio the natural ventilation must not be reduced it should be preferably by indirect means for warm air Naked flames and expose l and excessive surface temperature s cylinders should be protected from should be located in a safe p room g may be required Suchgrieating is provided am eam hot water or ments should not be used ided If necessary ive heat Any primary heat source ly remote from the manifold uch manifolds for holding cylinders used on trolleys in add re cylinders intended for use with the pipeline system 4 ature equilibration displays as appropriate Cylinder recog conforming to BS EN 1089 3 or BS EN 850 Lighting Manifold roors should be provided with lighting to an illumination level of 150 lux 15 lumens sq ft by means of bulkhead lighting fittings to IP 54 BS EN 60529 1992 Plantrooms other than manifold rooms should be provided
159. ersion 2 0 June 2001 Page 213 of 264 Borders General Hospital NHS Trust on behalf of NHSScotland Property and Environment Forum 15 184 15 185 15 186 15 187 15 188 15 189 15 190 15 191 SHTM 2022 Part 1 Medical gas pipeline systems Safety valve inspection Tests of safety valves are not required Procedure The procedure is as follows a inspect each safety valve to check that the discharge capacity and the set pressure are in accordance with the contract specification b check that the safety valves conform to BS 6759 Part 2 c inspect the certification supplied with each valve Results Record the results on Form B10 if they are in acc 15 72 ance with paragraph Warning system tests General The tests should be carried out fo time e nction at a time on one system ata All alarm systems shoul Stalled and in operation Procedure b observe wiat the appropriate changes in warning system conditions occur in ascordance with paragraphs 15 76 and 15 77 c check that the warning system will operate from the essential power source Results Record the results on Form B11 if they are in accordance with paragraphs 15 76 and 15 77 Verification of drawings Procedure Inspect the as fitted drawings to ensure that all variations from the contract drawings have been recorded Version 2 0 June 2001 Page 214 of 264 Borders General Hospital NHS Trust on behalf of
160. erve manifold M x id X im H HT OO PO PD X 7 So i lt PD ba B x Ve pec i _2 XxX X x D x kh DH S K To Version 2 0 June 2001 Page 62 of 264 Borders General Hospital NHS Trust on behalf of NHSScotland Property and Environment Forum SHTM 2022 Part 1 Medical gas pipeline systems Figure 4 Typical VIE layout and pipework configuration with VIE standby reproduced with kind permission of BOC ve LV Vj K UP V sa Version 2 0 June 2001 Page 63 of 264 Borders General Hospital NHS Trust on behalf of NHSScotland Property and Environment Forum SHTM 2022 Part 1 Medical gas pipeline systems Figure 5 Typical VIE layout and pipework configuration with liquid cylinder standby reproduced by kind permission of BOC a g e A ae Version 2 0 June 2001 Page 64 of 264 Borders General Hospital NHS Trust on behalf of NHSScotland Property and Environment Forum 6 15 6 16 6 17 6 18 6 19 6 20 6 21 6 22 6 23 6 24 6 25 SHTM 2022 Part 1 Medical gas pipeline systems Control piping and instrumentation The VIE pipework configuration will depend on the standby system The VIEs have top and bottom fill connections with a liquid outlet supply to the vaporiser and
161. es currently available to measure oil contamination These tubes give a quantitative response and are not intended for re use It may be appropriate if a nil reading is recorded to validate that the tube is functional by testing the tube on a known sample Record the results NOTE Non agent specific detector tubes are difficult to interpret and are not recommended because of their qualitative and not quantitative response Version 2 0 June 2001 Page 242 of 264 Borders General Hospital NHS Trust on behalf of NHSScotland Property and Environment Forum SHTM 2022 Part 1 Medical gas pipeline systems Appendix 6 Equipment for gas identification General The function of these tests is positively to identify medical gases by measuring their oxygen nitrous oxide and nitric oxide content The specified concentration limits for this purpose are given in Table 25 Portable equipment of the required specificity and sensitivity is commercially available NOTE N2 should be used as the inert gas shielg cargon dioxide should not be used AL Thermal conductivity meters do not giva oxide in the presence of carbon dioxi _ means of identification of nitrous e ideN specii nitrous oxide meter should be used If carbon dioxide pipelines carbon dioxide detector tube a postive identification of nitrous Specificity Oxygen Oxygen specifitts ing different measurement principles are currently ture The oxygen sensor sho
162. ess The depth of the recess should be 150 mm Version 2 0 June 2001 Page 29 of 264 Borders General Hospital NHS Trust on behalf of NHSScotland Property and Environment Forum SHTM 2022 Part 1 Medical gas pipeline systems Terminal units for nitric oxide oxygen carbon dioxide mixture BS 5682 does not include a terminal unit for nitric oxide or oxygen carbon dioxide mixture In the absence of standards the dimensions given are recommended They are based on the diagrams and tables in BS 5682 1984 as follows NOTE BS 5682 1984 has since been withdrawn and replaced by BS 5682 1998 Recommended probe dimensions for nitric oxide and oxygen carbon dioxide mixture CO less than 5 and NIST dimensions for nitric oxide Diameters of probe Service Identification symbol Nitric oxide O CO mixture CO2 lt 5 COs lt 5 Version 2 0 June 2001 Page 30 of 264 Borders General Hospital NHS Trust on behalf of NHSScotland Property and Environment Forum SHTM 2022 Part 1 Medical gas pipeline systems a Dimensions 27 75 0 5 0 2 54 110 15 gt 18 23 Ea 6 01 o5 E RO 30 N 9 n 11 562 0 15 ele N 12 TT 16 one I some o a Q Q LO il 1 o 1546 incl TE
163. est gas should be disconnected d all special connectors and cylinders should be removed from site Procedure The procedure is as follows a starting at atmospheric pressure except for vacuum systems fill each pipeline system to pipeline distribution pressure b with the supply system on purge each terminal unit with a known volume of gas at least equal to the volume of the pipeline being tested Version 2 0 June 2001 Page 215 of 264 Borders General Hospital NHS Trust on behalf of NHSScotland Property and Environment Forum 15 199 15 200 15 201 15 202 15 203 15 204 SHTM 2022 Part 1 Medical gas pipeline systems c leave each system at pipeline distribution pressure with the supply system connected Results Record on Form B13 that the systems have been filled in accordance with paragraph 15 86 Tests for quality The pipeline systems should be at pipeline distribution pressure and filled with the specific gas except for tests for particulate contamination which may be carried out with medical air if the system is not to be taken into use immediately Procedure The procedure is as follows hafid be carried out on ea system at the ude as a minimum the most ould normally be the first the results of the tests the QC ion of additional terminal units to be a the tests specified in paragraphs 15 88 a representative sample of termin discretion of the QC The sampl di
164. face masks flowmeters inadvertently left on poorly maintained anaesthetic or scavenging equipment etc Control of the risk is achieved by a combination of good housekeeping that is minimising leaks room ventilation and the removal of waste anaesthetic gases at source by a scavenging system This section covers the specification design and amp Stallation of anaesthetic gas scavenging systems AGSS Background The following anaesthetic gases an e typically used in general anaesthesia N O 6 litres min O gt 4 litres mi Halothane Isoflurane Enflurane The flammas anaesthetics such as ether and cyclopropane are no longer used Cyclopihgpane is no longer manufactured The AGSS is not usually designed for use with flammable anaesthetic agents Refer to Scottish Health Guidance Note Static discharges To ensure that all devices for example anaesthetic machines ventilators and breathing systems are suitable for the purpose the guidance given in BS 5724 Part 1 BS EN 60601 1 should be followed See also the Report of a working party to review the anti static requirements for anaesthetising areas Nitrous oxide and oxygen are usually supplied from the MGPS but the halogenated anaesthetic agents are supplied from a vaporiser on the anaesthetic machine Leakage and spillage can occur from the anaesthetic machine for example when filling vaporisers or if flowmeters are inadvertently left switched on Version
165. ferably be sited at roof level well away from ening windows and other apertures to prevent pollution iIding ventilation inlets t from re e Duplex sys 10 53 Where duplex systems are installed each pump should be capable of meeting the full design flow Version 2 0 June 2001 Page 138 of 264 Borders General Hospital NHS Trust on behalf of NHSScotland Property and Environment Forum 10 54 10 55 10 56 SHTM 2022 Part 1 Medical gas pipeline systems Plant control indication There should be indicators to show the following conditions Indication Legend a green mains on and air flow Normal b yellow duty pump failed plant fault C red system failed plant emergency Indicator panels should be installed in the operating room and the nurses station The air flow that is plant on indication should be initiated by either a pressure switch or air flow detection device at thegfump that is mains supply to the pump is not sufficient Version 2 0 June 2001 Page 139 of 264 Borders General Hospital NHS Trust on behalf of NHSScotland Property and Environment Forum SHTM 2022 Part 1 Medical gas pipeline systems 11 System design nitric oxide Nitric oxide pipeline installations Introduction Nitric oxide NO pipeline installations are a developing science at preliminary stages The following paragraphs are intended as best practice guidance at present The
166. fferential pressure at the inlet to the mixing panel is critical and should not exceed 0 5 bar g A pressure switch operated solenoid valve opens and shuts on a 0 5 bar g differential The main mixer solenoid valve opens when the line pressure falls to 4 2 bar g the standby mixer solenoid valve will open if the line pressure continues to fall to 4 0 bar g Version 2 0 June 2001 Page 109 of 264 Borders General Hospital NHS Trust on behalf of NHSScotland Property and Environment Forum 7 119 7 120 7 121 7 122 7 123 7 124 7 125 7 126 7 127 SHTM 2022 Part 1 Medical gas pipeline systems Two independent paramagnetic oxygen analysers are provided on each mixer to give continuous on line measurements lf the oxygen concentration falls outside 20 22 as measured by either analyser the mixer solenoid valve is held closed and the mixer is shut down In addition a signal is relayed downstream to close the solenoid valve on the buffer vessel associated with that mixer Buffer vessels Each mixer has associated with it a buffer vessel to smooth fluctuations in demand In the event that the oxygen concentration is outside the specification that is 20 22 the solenoid valve downstream of the buffer vessel will also close preventing air from the buffer vessel from entering the distribution system The buffer vessel together with appropriate hould be sized to match each mixing panel to provid
167. g and alarm systems General The provision of a warning and alarm system is essential to monitor the safe and efficient operation of MGPS There are three reasons for this monitoring a to indicate normal function of the pipeline system by means of visual indicators b to warn by visual and audible indication that routine replacement of cylinders or other engineering action is required the user This alarm condition will requir various departments staff A schematic diagram of a typical in Figures 16 and 17 uireepfor all medical gas and vacuum Warning and alarm systems a is required for surgical air systems and systems A much simplit providing inform on ali monitored functions with repeater panels tion is required to ensure the necessary action is Pressure sensors should be connected to the pipeline by means of minimum leak devices All MGPS warning and alarm indicating panels should comply with the requirements of this SHTM including all operating room panels Panel location Central indicator panel Warning and alarm conditions for all medical gases in a central system should be displayed on a central panel which is located in a position subject to continuous 24 hour observation such as the telephone switchboard room or the porters lodge Version 2 0 June 2001 Page 146 of 264 Borders General Hospital NHS Trust on behalf of NHSScotland Property and Environment Forum 12 8 12 9
168. g tripped green ma r cooler temperature high yellow compressor temperature high 7 0229 5 wp lt d o Z yellow for each individual safety device provided by the manufacturers g yellow compressor failure There should be indicators for each dryer system to show the following a green mains supply on b yellow dryness fault c yellow pressure fault Version 2 0 June 2001 Page 115 of 264 Borders General Hospital NHS Trust on behalf of NHSScotland Property and Environment Forum 8 25 8 26 8 2 8 28 8 29 8 30 8 31 SHTM 2022 Part 1 Medical gas pipeline systems Alarm signal status unit An alarm signal status unit should be provided as part of the control system lt should display the following conditions Indication Legend a green normal normal b yellow plant fault condition b g see 8 23 c see 8 24 c yellow plant emergency low reservoir pressure high moisture i e condition b see 8 24 d red pipeline pressure fault pressure fault Conditions b to d should be transmitted to the c Where relays are used they should be normall energise under fault conditions with contacts V dc 50 mA tral alarm system ergised relays which de minimum rating of 50 rated at 50 V dc 50 mA b to d to the alarm Alternatively volt free normally close should be provided for transmission syst
169. gery units this may result in mbers of AVSUs As a guide where there are fewer If possible in Vritical care areas such as ITUs and neonatal units each AVSU should control only half the total number of terminal units in each space Where two sets of terminal units are provided to each bed treatment Space consideration should be given to using one AVSU for one of each pair of sets Version 2 0 June 2001 Page 173 of 264 Borders General Hospital NHS Trust on behalf of NHSScotland Property and Environment Forum 13 78 13 79 13 80 13 81 13 82 13 83 SHTM 2022 Part 1 Medical gas pipeline systems NOTE Where pneumatically actuated pendant fittings are used the medical air Supply is typically used for the power source In this case closure of one of the medical air AVSUs may inactivate the pneumatic function as well as isolating half the terminal units The fact that the AVSU controls the pneumatic operation of such devices should be clearly labelled on both the AVSU and the relevant NIST connector in the pendant fitting The more sophisticated pendants may have three NIST connectors for medical air one for the pneumatic function and two for terminal units These would be isolated by two separate AVSUs In this case the NIST connectors should be clearly labelled showing which terminal units or pneumatic function are served and which AVSU isolates each NIST Labelling All valves should be clearly labell
170. h the supply system on each terminal unit must be purged at a known flow with a volume of gas at least equal to the volume of the pipeline being tested f all oxygen nitric oxide oxygen carbon dioxide mixtures nitrous oxide and nitrous oxide oxygen mixtures released during the purging process must be disposed to a safe place Purging is not necessary for vacuum systems Quality of compressed medical gas systems General The objective of these tests is to establish whether the pipeline has been contaminated during construction or modification With the exception of the Version 2 0 June 2001 Page 198 of 264 Borders General Hospital NHS Trust on behalf of NHSScotland Property and Environment Forum 15 89 15 90 15 91 15 92 15 93 15 94 15 95 15 96 SHTM 2022 Part 1 Medical gas pipeline systems particulate contamination and odour tests these tests must be carried out after the systems have been filled with the specific working gas Oxygen oxygen carbon dioxide nitric oxide and nitrogen must be vented to a safe place These tests are not required on a vacuum system These test procedures are based on existing practice The particulate contamination test is subjective in that it requires the quality controller QC to make a judgement on whether or not particles are visible on the filter The oil water carbon monoxide and carbon dioxide tests are intended to be carried out with detector tubes These
171. he test procedure set out in the British Standard should be followed as far as possible The operation of flow indicators power on indicators and alarm systems should also be checked For the purposes of diversity it may be assumed that in any operating department one receiving system for each operating suite is in use at any time Version 2 0 June 2001 Page 206 of 264 Borders General Hospital NHS Trust on behalf of NHSScotland Property and Environment Forum 15 140 15 141 15 142 15 143 15 144 15 145 15 146 15 147 15 148 15 149 SHTM 2022 Part 1 Medical gas pipeline systems Methods and procedures for validation and verification of medical gas pipeline systems General The procedure given here is an example only Other procedures may be used but validation of the test method should be documented The sequence of tests in this procedure is important and should be followed The general requirements of paragraphs 15 1 7 15 36 must be observed All tests will need to be planned and carried out by the appropriate persons Forward planning will be necessary to ensure that the necessary persons and test equipment will be available Summaries of the tests required on the pipeli s and on the total pipeline system are given in Tables 22 and car Labelling and marking Inspect each pipeline carcass to are labelled in accordance with the that the terminal unit base blo 5682 1998 u
172. hould be 450 mm Hg 60 kPa Vacuum indicators should comply with BS EN 837 1 or have an equivalent performance if electronic indicators are used Calibration should be 0 760 mm Hg 0 101 kPa All gauges should be a minimum scale length of 90 mm Vacuum indicators should be located on a the plant control unit indicating the vacuum in the pipeline ie on the pipeline side of the bacteria filter b each reservoir A differential vacuum indicator should be located across the bacteria filter All indicators should be connected directly to the pipework and not isolated by valves Version 2 0 June 2001 Page 124 of 264 Borders General Hospital NHS Trust on behalf of NHSScotland Property and Environment Forum 9 44 9 45 9 46 9 47 9 48 9 49 9 50 9 51 9 52 SHTM 2022 Part 1 Medical gas pipeline systems Electrical supply The electrical supply to the medical vacuum plant should be connected to the essential electrical supply A time delay system should be provided to avoid overloading the power supply on changeover Pump operating and indicating system General description The operating and indicating system should perform the following functions a overall plant control and indication b individual pump starting c plant status monitoring and indication alarm signal status unit Provided that the individual pump starters ar h d ing separate compartment the operating and indica
173. ial work Complete installation to 2nd fix stage X Carcass leakage Carry out system tests cross connect AVSU TUJ NIST no Pass yes pipeline system pi Purge wiin test gas or ____ Carry out particulate tests working gas Connect to medical air System now to be taken been maintained supply source itause OS no Fill to working pressure and leave pressurised Purge and fill with working gas Carry out gas identity and quality tests no yes no Carry out performance tests of total system yes a Remove Construction labels System available for use Version 2 0 June 2001 Page 183 of 264 Borders General Hospital NHS Trust on behalf of NHSScotland Property and Environment Forum 15 10 15 11 15 12 15 13 15 14 15 15 SHTM 2022 Part 1 Medical gas pipeline systems Tests for cross connection are made on the complete pipeline system These tests are of fundamental importance to the safety of the pipeline systems All supply systems and their major components should have certificates as specified in Model Engineering Specification C11 which show that they meet the design requirements of the pipeline system Validation and verification should only b
174. ides of nitrogen particularly nitrogen dioxide NO2 and dinitrogen trioxide N2O3 The rate of conversion depends upon both the concentration of nitric oxide and oxygen Version 2 0 June 2001 Page 140 of 264 Borders General Hospital NHS Trust on behalf of NHSScotland Property and Environment Forum SHTM 2022 Part 1 Medical gas pipeline systems The higher the concentration of both components the faster the rate of oxidation This is shown in Table 17 11 8 In the presence of moisture these compounds form nitric acid HNO3 and nitrous acid HNOz which will react with the traditional materials used for MGPS 11 9 Although during normal operation no part of the pipeline should become contaminated with oxygen and moisture experience has shown that such contamination Is possible Consequently the use of austenitic 303 stainless steel is recommended for terminal units non interchangeable screw thread NIST connectors pipeline installation components and manifolds Elastomeric components used for valve seats low pressure flexible connecting assemblies etc should be compatible with nitric oxide Table 17 Nitric oxide conversion rates NO ppm AL v 02 20 120 Time min O with different mixtures of NO in nitrogen Provision o terminal units valves and area valve service units AVSU s 11 10 In highly serviced ward areas such as neonatal intensive care units and ITUs it is normal policy to provide at
175. ieving type Test point A test point comprising shut off valve and terminal unit should be provided to permit sampling of the medical air quality Safety valves Safety valves should be provided in accordance with the system requirements given below All safety valves should conform to BS 6759 Part 2 1984 A safety valve of the certified discharge capacity stated should be fitted in each of the following positions a onthe delivery pipe of each compressor and upstream of any isolating valve non return valve or after cooler capab of discharging the total throughput of the compressor safety valves on the dryer colum protected by a safety valve on th is already sufficiently protected c immediately downstream ssure regulator capable of discharging the syste All safety valves should de of tht closed bonnet type and connected to Suitably sized pipeyse outside The seigoress e safety valves should be as given in Appendix 10 Traps an Automatic ditinage traps Electrically or mechanically operated automatic drainage traps should be provided on the after coolers receiver separators and coalescing filters The discharge from these drainage traps should be piped to a suitable gulley Co ordination with building work is required for this provision NOTE See paragraphs 7 34 to 7 38 for effluent discharge requirements Drainage and tun dishes are usually provided under the building contract Separators sh
176. in the ich are most commonly available are a recipr ing baton compressors b rotary ressors c rotary SC ew compressors The compressors may be of any type provided they are suitable for continuous running on load and for start stop operation If reciprocating compressors are used they may be either single or two stage although for a 400 kPa system a single stage compressor is usually satisfactory Compressors for medical air systems are selected by plant manufacturers from the range of units currently available for industrial users and should be selected for their reliability and performance Version 2 0 June 2001 Page 90 of 264 Borders General Hospital NHS Trust on behalf of NHSScotland Property and Environment Forum A A oe D Exviros SHTM 2022 Part 1 Medical gas pipeline systems Figure 10 Typical medical air 400 kPa system reproduced by kind permission of MIM Inlet a i i 3 pump system LNY Ly A 7S Ae Oa P lt 7 Pressure ws Lo relief valve lt 7 PRV X AA Filter ar Pressure d Inlet r Jags Compressor After i p 7 cooler with PRV Non return valve gt i a F
177. indication of tions Operation of th any subseque Panel leg play The panel leyend and display should be as shown in Table 19 Area warning and alarm panel Displays Area panels should display normal emergency alarm and alarm system fault conditions as given in paragraph 12 49 Mute functions The temporary mute should cancel the audible signal for about 15 minutes whilst the visual indicator continues to flash Operation of the mute should not inhibit the visual or audible indication of any subsequent alarm conditions Version 2 0 June 2001 Page 157 of 264 Borders General Hospital NHS Trust on behalf of NHSScotland Property and Environment Forum 12 62 12 63 12 64 12 65 12 66 SHTM 2022 Part 1 Medical gas pipeline systems Panel legend and display The panel legend and display should be as shown in Table 20 Location The initiating devices for local area alarms should be located after designated AVSUs This designated position will normally be after the final AVSU The area alarm panel should be located where it will be clearly visible for example in the operating room or at the reception desk not in a corridor or unmanned area Area alarm panels should be designed similarly to central alarm panels All alarm indicators installed in operating departments should comply with the requirements of this SHTM and any medical gas vidicator should similarly comply with these require
178. ion fittings may be used Mechantal i ould not be used elsewhere for general pipework installa ade where pipelines are the flux reSidues and copper oxides created by this process should be chemically removed and if necessary the complete assembly must be cleaned and degreased for oxygen service c no flux should be used for making joints on site Joints must be carried out under controlled conditions off site and sub assemblies delivered to site NOTE Where brass gunmetal bronze fittings form part of an installation they should be supplied to site individually packed and complete with copper pipe tails brazed to them so that these fittings can be joined to the pipeline installation by fluxless brazing Because of this requirement it will be necessary for a copper to copper brazed joint to be made adjacent to these fittings for example in a wall adjacent to a terminal unit or a valve Version 2 0 June 2001 Page 164 of 264 Borders General Hospital NHS Trust on behalf of NHSScotland Property and Environment Forum 13 29 13 30 13 31 13 32 13 33 SHTM 2022 Part 1 Medical gas pipeline systems Brazing copper to copper joints a brazed joints should be made using a silver copper phosphorus brazing alloy to BS EN 1044 No flux should be used b brazing should be carried out using oxygen free nitrogen as an internal inert gas shield to prevent the formation of oxides on the inside of the pipes and fit
179. itional supply syste he terms oxygen concentrator and PSA are interchangeable T systems should be considered are those sit for a bulk liquid vessel cannot be me le very restricted sites Otherwise PSA systems should only Qe i when an investment When installed a PSA syste iV product gas via the oxygen pipeline system Oxygen concentrators Gyerate b adsorbing under pressure other gases in the atmosphere hich have specific physio chemical properties thug athe oxygen which is stored and transmitting it for use The adsorbws Known as artificial zeolites and are more commonly ar sieves The sieves are arranged in pairs one adsorbing gt other regenerates The waste product essentially nitrogen is WEcharged to atmosphere during regeneration of the adsorbents some systems the use of vacuum increases the efficiency of the regeneration adsorption process Regeneration requires the use of a small proportion of the product gas The PSA process has reached a high level of technical sophistication and is capable of producing oxygen with a concentration of about 95 For the UK the minimum level below which the emergency reserve manifold will come into operation is 94 The remainder is mainly argon with some nitrogen The highest concentration is not likely to exceed 97 98 except when the emergency reserve manifold is in use when it will be 100 The major components of a PSA system and their layout
180. iv compressor temperature high v compressor run up time too long vi activation of other safety devices supplied by the manufacturers Version 2 0 June 2001 Page 85 of 264 Borders General Hospital NHS Trust on behalf of NHSScotland Property and Environment Forum 6 120 6 121 SHTM 2022 Part 1 Medical gas pipeline systems b plant faults for each molecular sieve unit i control circuit failed li vacuum pump called for iii overload tripped iv activation of any of the safety devices supplied by the manufacturer v oxygen concentration failure a A A A A vi pressure fault c plant emergency i oxygen concentration failed at below 94 concentration ii receiver pressure 0 5 bar g below the standby cut in pressure iil dryness above 0 51 mg m dewpoint 26 C at atmospheric pressure d pressure fault cylinder reserve i pressure in each bank below 50 ono der pressure e pressure fault pipeline i low pipeline pressure ii high pipeline pressure Plant status indicator un ication there should be a plant status nted on the plantroom wall or adjacent to nit or the plant control unit It should have a ies with BS 5378 to indicate the presence of low In addition to the plant indicator panel whig either the comps warning notice voltage There sho Irrercators for each compressor to show the following conditions a green mains sup
181. l Non return valve L Supply connection Exhaust OO Supply isolation valve Relief valve LL bea B Pressure switch 505mm ee Version 2 0 June 2001 Page 58 of 264 Borders General Hospital NHS Trust on behalf of NHSScotland Property and Environment Forum 6 1 6 2 6 3 6 4 6 5 6 6 SHTM 2022 Part 1 Medical gas pipeline systems 6 System design oxygen supplies Bulk liquid oxygen systems and vacuum insulated evaporator VIE General A VIE can be used for the storage of any cryogenic liquid which can include in healthcare premises oxygen nitrogen and nitrous oxide The VIE is a cryogenic pressure vessel made of stainless steel supported within an outer vessel similar to a vacuum flask The VIE plant has advantages over other oxygen supply systems where high demands exist and is used whenever it can be shown to be more economical provided a suitable location is available Bulk liquid oxygen installations sho gant manual handling savings over conventional cylinder manifold he system usually remains the property and respo
182. l NHS Trust on behalf of NHSScotland Property and Environment Forum 15 159 15 160 15 161 15 162 15 163 15 164 15 165 15 166 SHTM 2022 Part 1 Medical gas pipeline systems Results The rate of pressure drop during the test period should not exceed the value specified in Table 23 after allowing for pressure changes due to temperature variation Record the results on Form Bs Leakage into vacuum systems The leakage test described above should have been completed satisfactorily All terminal unit valves and other devices such as pressure sensors should be fitted The vacuum supply should be connected to the system under test Procedure Connect a vacuum gauge to the system Run the vacuum supply system to maintain pipeline distribution pressure until the pig line system is dried out With the system at pipeline distribution press system Note the vacuum initially and again Results ure Iferease after one hour should allowance for temperature Record the results on Form B4 Tkg p not exceed 10 mmHg There is no variation in this test Closure of AVSUs The test specified satisfactorily anaraphg715 50 15 53 must have been completed iS test is as follows a connect dsressure measuring device to the system The system should be at pipeline distribution pressure with all AVSUs closed b depressurise the pipeline downstream of all AVSUs by inserting and leaving an o
183. l medical demands on the system Continuity of supply is achieved by the specification of a system which with the exception of liquid oxygen systems which may include a secondary vessel have duplicate components and by the provision of an adequate emergency reserve supply for all systems except vacuum by the provision of alarm systems and by connection to the emergency power supply system Anaesthetic gas scavenging systems AGSS and high pressure surgical air systems are not considered as life support systems and therefore duplicate components and in the case othe latter an emergency reserve supply system are not norm gily required For operational reasons reserve air cylinders co th regulators are usually available for surgical tools in operati Quality of supply is achieved by the us asus purchased to the appropriate Ph Eur requirements or N plant performing to C specified standards by the mainte cleanliness throughout the installation of the system an leMentation of the various testing and commissioning procedure yt Installation su equ ment maintenance The installatio registered to BS defined hould only be carried out by specialist firms ISO 9000 with scope of registration appropriately Modificaticns Special precautions are required when existing installations are to be modified or extended to ensure that all sections of the pipeline system remaining in use are not contaminated and that the
184. lace a single filter into the filter holder b assemble the filter holder so that it seals c set the flow controller to 150 l min d connect the filter holder to the terminal unit for 30 seconds e inspect the filter Evaluate and record the result Version 2 0 June 2001 Page241of264 Borders General Hospital NHS Trust on behalf of NHSScotland Property and Environment Forum SHTM 2022 Part 1 Medical gas pipeline systems Appendix 5 Equipment for contaminant testing General The function of these tests is to establish whether the pipeline has been contaminated during construction or modification The specifications for the permissible concentrations of each component are summarised in Table 24 Simple equipment which is of the required sensitivity and is suitable for use on site is commercially available Measurement principle quantitatively with the compound to b change along the length of the tube Tubes are available with appr water carbon monoxide oxides of nitrogen dioxide sulphur dioxide and higher Procedure ter carbon monoxide and carbon dioxide necting a tube and pump for each contaminant to a s connected to the pipeline at a flow of 2 to 5 l min draw a known volume of gas through the tube at re the gas being tested should be allowed to escape freely to a safe area and allow evaluation of the concentration of the compound being measured It is possible to There are tub
185. lexible connection Shut off valve Air receiver Filter Drain Inlet T Pi Compressor After cooler with PRV Non return valve LA Flexible connection Dew point alarm switch Drain Drain Filter Dryer ilte AA p Z X Shut off Shut off valve valve rain Shut off Water Shut off valve Oil filter separator valve Le p al l Filter X Y plat Source of Pipeline operating distribution supply system Line hut off Shut off pressure KI S vals regulator valve gt lt t _ lt lt gt 4 O N l P lt PA gt lt d gt lt x Shut off Bacterial tL valve filter X Notes Emergency 1 Drains marked are dirty oil water Test dolni inlet 2 Filters marked gt are activated carbon to p remove smells From emergency Version 2 0 June 2001 reserve supply Borders General Hospital NHS Trust on behalf of NHSScotland Property and Environment Forum Page 91 of 264 7 13 7 14 7 19 7 16 7 17 7 18 7 19 7 20 SHTM 2022 Part 1 Medical gas pipeline systems Compressor lubrication Compressors may be oil lubricated provided that suitable arrangements are made to ensure that the air quality specification given in Table 1 is fulfilled Rotary compressors are sealed and cooled by oil or water Oil control is therefore essential and is usually provided as an integral part of the compressor Reciprocating compressors may be oil lubricated carbon ring PTFE ring or diaphragm sealed t
186. lf of NHSScotland Property and Environment Forum 10 11 12 SHTM 2022 Part 1 Medical gas pipeline systems Appendix 7 Procedures for measuring the design flow of vacuum plant General A method is described which enables a large vacuum system to be run at the system design flow using a minimum quantity of calibrated test equipment Measuring principle A calibrated orifice device is connected to the syst that the plant runs at the system design flow T then noted close to the plant so acuum at that point is mb uncalibrated leaks same level of vacuum at The calibrated orifice is then removed and a are introduced throughout the system ive t the plant Test equipment re available Suitable calibrated orific IC Uncalibrated leaks may ve cons jucted from medical gas probes connected to large AMAL jet S uitable diameter tubing Procedure Connect t meter orific eter at a Suitable point adjacent to the plant Set the ystem design flow Run the plant zontinuously with the pipeline system isolated Record the pressure on the vacuum gauge Reconnect the pipeline system to the plant Close the meter orifices leaving the vacuum gauge connected Insert non calibrated leaks at suitable points throughout the pipeline system Adjust the number and size of the non calibrated leaks until the vacuum gauge at the test point shows the same reading as in paragraph 8 above The system will
187. lf of NHSScotland Property and Environment Forum 8 16 8 17 8 18 8 19 8 20 8 21 SHTM 2022 Part 1 Medical gas pipeline systems Alarm signal status unit The following indication of manifold conditions should be provided Indication Legend a agreen normal normal b a yellow duty bank empty change cylinders standby running condition c a yellow duty bank empty change cylinders immediately standby low condition d a red pipeline pressure fault pressure fault indicator Conditions b to d should be transmitted to the central alarm system Where relays are used they should be normall ergised relays which de energise under fault conditions with contacts minimum rating of 50 V dc 50 mA rated at 50 V dc 50 mA b to e to the alarm Alternatively volt free normally close should be provided for transmission system ac on The panel can be incorporate nifold indicator unit or be a separate unit within the be monitored for open gnort circwit a the event of such a cabling fault a red system fault lamp sho inated on the alarm signal status unit together with the Compressor s The comp recommen plant operati erating system should be based on the ns for 400 kPa compressor systems except that simplex only would be required Plant status monitoring A monitoring system should be provided to detect the following faults in the air compress
188. line 6 pipeline is omitted General con tions 15 151 The pipeline should be completely installed and correctly supported The base blocks of all terminal units should be fitted and blanked Other devices such as safety valves or pressure sensors need not be fitted All connection sockets for such devices should be blanked Procedure 15 152 Connect a suitable pressure measuring device to the pipeline Fill the pipeline with test gas at the specified test pressure Disconnect and remove the gas supply Record the pipeline pressure and room temperature initially and again at the end of the test period 2 24 hours Version 2 0 June 2001 Page 208 of 264 Borders General Hospital NHS Trust on behalf of NHSScotland Property and Environment Forum 15 153 15 154 15 155 15 156 15 157 15 158 SHTM 2022 Part 1 Medical gas pipeline systems Results The rate of pressure drop during the tests should be less than 0 025 per hour except for pressure changes due to temperature variations The pressure change due to temperature variation is approximately 0 35 per C Record the results on Form B1 Cross connection Any links between the systems should be removed before this test is carried out All pipelines should be at atmospheric pressure and all AVSUs should be open A single pressure source should be used and connected to one pipeline at a time This should remain under pressure throughout the test At least
189. liveries of bulk liquid oxygen should be tested for conformance to the product licence specification before despatch by the supplier and should be supplied with a certificate indicating compliance Cylinder storage and handling There should be recorded visual checks for correct labelling including batch numbers See the Operational management pagg of this SHTM Removal of construction labels When all tests have been completed satisfact which were fixed to the terminal unit the authorised person MGPS ily construction labels O emoved on the authority of Anaesthetic gas scave General fy the tests to be carried out on AGS British Standards The tests specified are We that the system performs in accordance with iC tion and safety tests to ensure that the safety criteria tested to ascertain their performance and to ensure that the criteria for patient safety can be achieved The tests for performance and safety criteria are described in this Chapter It is recommended that all AGSS are tested at commissioning and that the tests are repeated yearly or more frequently if there is reason to suspect that the performance of the system is not satisfactory Monitoring staff exposure to anaesthetic gases is recommended in the Operational management part 2 of this SHTM in order to comply with the requirements of COSHH The results of such monitoring will identify potential inadequacies in the AGSS
190. lt The system should monitor the integrity of the lines between the initiating devices and the panel or transmitter units The a zrm system fault condition should be indicated on loss of integrity for ex en or short circuits le Communication wiring fault The system should indicate an alar t in the event of loss of data transmission between panels and 4ranSwitters Mains power failure Failure of mains power audible signal which s audible signal ma under normal p should continu has discharged own by a flashing red indicator and an red from an internal battery The not automatically reinstate as required paragraph 12 19 but the visual indicator il either the fault has been rectified or the battery Standby b A battery sho d be provided with sufficient capacity to power the visual and audible alarm system fault signal for a minimum period of four hours The battery should be sealed and exchangeable and should automatically recharge within 72 hours Legend The legend on this indicator should be alarm system fault Version 2 0 June 2001 Page 154 of 264 Borders General Hospital NHS Trust on behalf of NHSScotland Property and Environment Forum 12 37 12 38 12 39 12 40 12 41 12 42 12 43 12 44 SHTM 2022 Part 1 Medical gas pipeline systems Indicator panel requirements for all systems Indicators Panels should be provided with all indicators for the gas
191. ly desirable that tests for particulate Wi should also be carried out on the existing system prior to an of the hospital authority to ensure th tevits are carried out prior to the design phase of any modifications or management to ensure that reme system The tests for particulate ion on any extension or modification should only be carried The exact tests modification e performance of as possib en in Table 23 viously depend on the nature of the specification should be prepared for the Version 2 0 June 2001 Page 187 of 264 Borders General Hospital NHS Trust on behalf of NHSScotland Property and Environment Forum SHTM 2022 Part 1 Medical gas pipeline systems Table 23 Validation and verification pressure during pipeline system tests Medical gas Pipeline distribution Terminal unit test Max pressure Min pressure this Plant pressure kPa flow l min see drop in pipeline may vary by 5 pressure Design at system between max flow kPa considerations for design flow kPa and static condition design flows kPa Os 400 10 100 40 370 430 490 N20 NO 15 Medical air 20 80 400 kPa O2 N2O 400 20 90 310 430 490 mixtures 275 inhalationary gasps Surgical air 770 350 110 700 kPa at 350 See 700 kPa I min max 900 kPa Design Vacuum 15 34 15 35 15 36 at no flow condition consider ations 53 3 kPa 40 0 kPa 300 mm 400 mm Hg Hg below standard atmospheric pressure of 101
192. matically supply oxygen and simultaneously a standby in use alarm will be given Version 2 0 June 2001 Page 67 of 264 Borders General Hospital NHS Trust on behalf of NHSScotland Property and Environment Forum SHTM 2022 Part 1 Medical gas pipeline systems Figure 6 Safety distances for cryogenic storage vessels reproduced by kind permission of BOC and BCGA Size of Storage TABLE 1 SEPARATION DISTANCES LIQUEFIED FLAMMABLE GASES FLAMMABLE LIQUIDS AND OXYGEN STORAGE Liquid a LPG Storage Oxygen Weight Equivalent Separation b Other Bulk Flammable Liquids and Liquefiable Vessel Capacity Liquid Capacity Distance Flammable Gases Tonnes Tonnes m 15 C Metres 0 1 1 The separation distances listed above for LPG 1 1 4 0 2 2 7 8 should apply to the same stored volumes m of 4 0 60 0 7 8 117 0 other bulk liquefied flammable gases and may be 60 0 150 0 117 0 124 0 used for the same stored volumes m of bulk 150 0 amp above 294 0 amp above flammable liquids These distances may be reduced depending on the nature of the flammable LPG cylinders and other liquefied liquid and any protective measure and in these flammable gas cylinders above cases and individual assessment of the proposed 50kg total capacity location shall be carried out Common examples of liquefied flammable gases suppliedgin cylinders include ammonia sulphide and ethylene oxide ples of bulk flammable liquids
193. maximum flexibility surgical air should be provided in all theatres The diversified flow is based on the assumption of 350 l min for the first theatre and 25 of the remainder see Table 12 Because surgical tools are used only for specific applications it is unlikely that more than one tool is actually in use at any given time even in a large operating department comprising several theatres Version 2 0 June 2001 Page 46 of 264 Borders General Hospital NHS Trust on behalf of NHSScotland Property and Environment Forum SHTM 2022 Part 1 Medical gas pipeline systems Table 10 Medical air 400 kPa design and diversified flows Department Design flow for each terminal Diversified flow Q l min unit l min In patient acute Ward units single and multi n 1 10 bedrooms 20 QW 20 z Treatment rooms Each ward unit 20 _ E QD QW mu Departments comprising 2 several ward units ITU and CCU 80 80 80 nB 1 D Adult acute day care Major treatment room Endoscopy room 40 Maternity department l 40 Delivery suite QM 40 T 1 Pa Normal delivery room NU QM 40n 40 Operating suite QM 40 T 1 Ea Neonatal unit 40 QN 40nB Dental department QT 40 T 1 40 Major dental oral s 40 QDENT 40 T 1 Ar Operating departm 40 Operating ro 40 QT 40 T 1 P 40 Anaesthetic roo 40 QA 40 A 1 T _ 10 Recovery 40 QR 40 nB 1 40 Plaster room 40 QP 40
194. ments several AVSUs the Itiplexed to a single For multi theatre complexes and critical carevare signals from each theatre area alarm el my be alarm panel Version 2 0 June 2001 Page 158 of 264 Borders General Hospital NHS Trust on behalf of NHSScotland Property and Environment Forum SHTM 2022 Part 1 Medical gas pipeline systems Table 19 Signals and display locations on central alarm systems Plant Alarm condition Legend Colour Auditory Location signal ABCD Cryogenic oxygen 1 VIE low lt 50 Refill liquid Yellow Yes AB plants 2 VIE low lt 25 Refill liquid Yellow Yes AB immediately Automatic 1 duty bank empty Change cylinders Yellow Yes ABD manifolds standby bank running 2 standby bank below 10 capacity 14 bar Change cylinders Yellow Yes ABCD N20 immediately Medical air 1 Plant fault Plant fault Yellow Yes AB compressor 2 Plant emergency Plant emergency Yellow Yes ABC Surgical air supply 1 system fault Change cylinders Yellow Yes AD plant fault 2 emergency reserve Reserve bank Yellow Yes AD low if installed empty plant Medical vacuum 1 Plant fault Yes AB plant 2 Plant emergency Yes ABC Oxygen 1 Plant fault Yes AB concentrator 2 Plant emergency cy Red Yes ABC Compressed Reserve pressure Re Yellow No AB cylinders on below 68 bar lt 14 bar reserve manifold for N2O serving an automatic manifold Compressed air Pressure n either Reserve low Yellow No ABC cylinders on reserv
195. n NHS residential care properties Fire precautions in existing hospitals Fire risk assessment in hospitals Textiles and furniture Version 2 0 June 2001 BSI Standards BSI Standards BSI Standards BSI Standards BSI Standards P amp EFEX P amp EFEXx P amp EFEX P amp EFEX P amp EFEX P amp EFEXx HMSO HMSO HMSO EEF P amp EFEX P amp EFEX P amp EFEx P amp EFEX P amp EFEX P amp EFEX P amp EFEX P amp EFEX Borders General Hospital NHS Trust on behalf of NHSScotland Property and Environment Forum Version 1 1 Page 262 of 264 SHTM 2022 Part 1 Medical gas pipeline systems ID SFPN 3 Escape bed lifts P amp EFEx SFPN 4 Hospital main kitchens P amp EFEx SFPN 5 Commercial enterprises on hospital P amp EFEX premises SFPN 6 Arson prevention and control in NHS P amp EFEx healthcare premises P amp EFEx P amp EFEx SFPN 7 Fire precautions in patient hotels SFPN 10 Laboratories on hospital premises UK Health Technical Guidance EH 40 HSE Occupational Exposure limits Annual C54 The keeping of LPG in cylinders and similar containers MES Model Engineering Specifications l 1997 As required Model Water Byelaws DA I HMSO Dept of the Environmen Occupations exposure sta Dept of i Health Advice on th i Dept of Health and i Health Health Service Advisory Committee Y ode orpractice 19 Bulk liquid oxygen orage at users premises Revision 2 K sitish Compressed
196. n rruptible or interruptible with variable Earthing uld onded to the consumer s earth terminal as required by e IEE Regulations This bonding should be made as e to the point at which the pipeline enters the building from the plant Tht size of the bonding conductor should be in accordance with Table 54f of thie Regulations The pipelines should not themselves be used for earthing the electrical equipment Pipelines Regulatio Flexible pipeline connections between the compressors or vacuum pumping plant and the fixed pipelines should be bonded across to comply with this requirement Flexible connections in the fixed pipelines should not normally be used but if they are specially approved they should be similarly bonded across Installation of electrical cables Distribution pipelines should preferably be physically separated from the metal sheath and armour of electric cables as well as from metal conduits ducts and trunking and bare earth continuity conductors associated with any electric cables which operate at low voltage or above Reference should be made to SHTM 2007 Electrical services supply and distribution Version 2 0 June 2001 Page 21 of 264 Borders General Hospital NHS Trust on behalf of NHSScotland Property and Environment Forum 2 43 2 44 2 45 2 46 2 47 2 48 2 49 SHTM 2022 Part 1 Medical gas pipeline systems When physical separation is impracticable or where there might be contact
197. nctional tests o Pressure saf units system ystems e p Carbon monoxide 15 102 Carbon dioxide 15 104 Nitrogen 15 105 Pipeline odour Gas identification Requirements before a MGPS system is taken to use 15 111 General Operational policy Cylinder storage and handling Removal of construction labels Page 12 of 264 Borders General Hospital NHS Trust on behalf of NHSScotland Property and Environment Forum 15 134 15 140 SHTM 2022 Part 1 Medical gas pipeline systems Anaesthetic gas scavenging systems 15 118 General Performance tests disposal systems 15 123 Powered device 15 125 Pipework ductwork installation 15 127 Performance testing 15 132 Receiving system Performance efficiency Methods and procedures for validation and verification of medical gas pipeline systems 15 140 General 15 146 Labelling and marking 15 148 Sleeving and supports 15 150 Leakage 15 154 Cross connection 15 157 Leakage from compressed algas systems 15 160 Leakage into vacuum syste 15 163 Closure of AVSUs 15 166 Zoning of AVSUs 15 170 Cross connection 15 180 System 15 184 Safety 15 187 Wage edical air ing and filling with specific gas Appendix 1 Testing commission and filling for use Forms to be completed during testing and commissioning of piped medical gases systems page 218 Appendix 2 Gas pressure variation with temperature page 236 Appendix 3 Pressure drop test device page 238
198. nd Environment Forum 4 19 4 20 4 21 4 22 4 23 4 24 4 25 4 26 SHTM 2022 Part 1 Medical gas pipeline systems Pressure requirements for surgical air are based on the requirement that the minimum pressure should be 700 kPa at the point of use that is the terminal unit at a flow of 350 l min Details of pressure requirements for all systems are given in Appendix 10 Oxygen In patient accommodation Oxygen is used at a typical flow of 5 6 litres min Each terminal unit should however be capable of passing 10 l min at STP at a supply pressure of 400 kPa nominal as shown in Table 4 in case nebulisers or other respiratory equipment is used The diversified flow to each six bed room is calcw ated on the basis that 10 treatment room for the purpose o ward the number of terminal units ting the diversified flow QW to the Table 6 may be taken as the comprises ber of identical ward units where this is not the case the diversified flowy is QW for the first or largest ward unit plus 50 of the total for the remaining ward units If one ward unit is significantly larger than the others average the flows from the ward units to obtain a more realistic flow Version 2 0 June 2001 Page 38 of 264 Borders General Hospital NHS Trust on behalf of NHSScotland Property and Environment Forum 4 2 SHTM 2022 Part 1 Medical gas pipeline systems Hyperbaric oxygen chambers Monoplace hy
199. nd vacuum systems for test purposes Water This test is intended to identify contamination of the pipeline system by moisture It should not be confused with the test for compressor plant dryer performance although it may indicate a failure in the dryer system The plant test point and a representative sample of terminal units distributed throughout the pipeline systems should be tested for total water content The water content must not exceed 115 vom The typig amp l water content of y be measured using The most distant terminal units on eac system supplied from a compressor A systems must be tested for carbon monoxide although it lly be necessary to test more than five terminal units The c tion of carbon monoxide should not exceed 5 ppm v v This ured at up to five terminal units in each system using the ap vices described in Appendix 5 dical air pipeline Carbon dioxide The most distan each branch of a medical air pipeline system supplie aaa pressor or an oxygen concentrated plant must be tested for caroWa dioxide The concentration of carbon dioxide must not exceed 5 Carbon dio must not be used as the inert gas shield during brazing Version 2 0 June 2001 Page 201 of 264 Borders General Hospital NHS Trust on behalf of NHSScotland Property and Environment Forum 15 104 15 105 15 106 15 107 15 108 15 109 15 110 SHTM 2022 Part 1 Medical gas pipeline systems Nitrogen Nit
200. ng faults in the i control ciait failed li m iii afte Zooler temperature high iv compressor temperature high v compressor failed to go on load vi activation of other safety devices supplied by the manufacturers c plant faults for each dryer unit i dryer failure ii pressure fault d plant emergency i receiver pressure 0 5 bar below the standby cut in pressure ii receiver pressure 0 5 bar above cut out pressure iil dryness above 0 51 mg m dewpoint at 26 C at atmospheric pressure Version 2 0 June 2001 Page 100 of 264 Borders General Hospital NHS Trust on behalf of NHSScotland Property and Environment Forum 7 69 7 10 7 71 SHTM 2022 Part 1 Medical gas pipeline systems e pressure fault cylinder reserve i pressure in duty bank below 50 of normal cylinder pressure f pressure fault pipeline i low pipeline pressure ii high pipeline pressure Plant status indicator unit In addition to the plant control indication there should be a plant status indicator panel which may be mounted on the plantroom wall or adjacent to either the compressor starter unit or the plant control unit It should have a warning notice which complies with BS 5378 to indicate the presence of low voltage There should be indicators for each compressor conditions how the following green mains supply on yellow control circuit failed yellow
201. nifold size and quantity of hospital stock should be dictated by a particular hospital s requirements Siting requirements It is not recommended that liquid cylinders are installed within buildings they should be installed in the open air in an enclosureg esigned for the purpose building or a confined area but only cylinder vents will be connected i control valve This valve should be cylinder relief valve setting t safe area in a safe manner pressure below that of the liquid y excess pressure Is vented to a Where installed in buil means of fully louvred s ventilation should be provided by rs to the outside Qs ge ess d The appropria ventilation ation must be made to ensure that there is adequate The site s cylinders ge from obstructions with sufficient access to the liquid old control panel and fill point The floor on which the liquid cylinders will be located and where they will be filled should be concrete hard standing strong enough to support the weight of the cylinders when full The floor should be level but designed to avoid any accumulation of water in the vicinity of the liquid cylinders The cylinders should be located at least 3 metres from a open sewers drains b pits c trenches d any openings to underground rooms enclosures e any combustible materials Version 2 0 June 2001 Page 77 of 264 Borders General Hospital NHS Trust on behalf of NHSS
202. ning c individually fused separate cycling systems for each dryer d asystem to control regeneration of the dryers in relation to pipeline demand e adewpoint meter and a pressure sensor f an automatic changeover to the standby dryer system in the event of failure of the duty unit by either dryness or pressure This requires Version 2 0 June 2001 Page 99 of 264 Borders General Hospital NHS Trust on behalf of NHSScotland Property and Environment Forum 7 68 SHTM 2022 Part 1 Medical gas pipeline systems i electrical and pneumatic isolation of the duty sub assembly so that it is taken off stream ii electrical and pneumatic energisation of the standby sub assembly so that it is brought on stream lil activation of the appropriate fault indicator and associated volt free contacts iv the sub assembly to remain in this mode of operation until the fault has been rectified green function indicators for each dryer sub assembly to indicate i dryer 1 selected ii dryer 2 selected iii selected dryer Normal iv selected dryer failed this fault indica manually reset by means of a reset b a fail safe system which on failure of theo following i closure of the exhaust and sk Should remain until causes the S air compressor system ii Opening of the inlet and out v Plant status monitoring A monitoring system 1g ed to detect the followi
203. nsibility of theas er who retains full legal responsibility for compliance wit malatenarice requirements and the Pressure Systems Safety Regul The hospital should be made awareS wth the medical gases contractor hospital alarm system neral operating principles by ed to include the VIE system in the Consideration should b given tthe legal and operational management consequences of 8g awiitfergnt supplier of oxygen on the same pipeline system Any co involving different suppliers should clearly state the obligations and ny The cons continuity o demand an ygen is increasing steadily and in order to ensure plyt is essential that the VIE is correctly sized for the hat a telemetry system is installed System sizing The liquid oxygen vessel is normally selected to provide for at least 14 days consumption An emergency back up supply equivalent to 24 hours average use should be available on site This may be provided by bulk liquid liquid cylinders or compressed gas cylinders as appropriate for each site A maximum of 20 cylinders are normally connected to the emergency manifold ten on each bank Where it would be impractical to hold 24 hours Supply in cylinders on site for example in a large teaching hospital consideration should be given to the ease of supply in an emergency for example proximity to gas supplies depots telemetry systems etc to see whether it would be possible to red
204. nsilenced pump should not exceed the following values for individual pumps Power Noise level 5 kW 75 dBA 5 1 15 kW 82 dBA 15 kW 89 dBA A suitable acoustic enclosure may be required in the purchase specification for all pumps with a free field noise level at 1m of 29 dBA or over An enclosure should produce a reduction of at leas 70 dBA in the free field noise level at 1m Vacuum plant exhaust The position of the termination point of windows ventilation intakes an equipment since for oil lubricated polluted with oil fumes refully chosen to be clear ke of air compressors and other S vacuum exhaust is likely to be Noise from the exhaust should sidered and a silencer fitted The construction d to the following criteria ized to give a back pressure at system design a the exhaus i ched to the pump performance flow is oint should be provided with protection to reduce the ind pressure and prevent the ingress of rain snow insects or animals c weatherproof notices should be fixed at the discharge point s with the legend medical vacuum discharge point do not obstruct d the exhaust pipe should be provided with a drainage valve at its lowest point e asilencer should be fitted on the exhaust pipe from each pump This may be integral with the pump unit Efficiency The efficiency of the plant should be measured at 100 and 10 of system design flow The efficiency should not be les
205. nstream of the manifold line pressure regulator and the main isolation valve A pressure safety valve should also be installed between the emergency reserve manifold and the pipeline distribution system It should have a flow capacity at least equal to that of the pressure regulator immediately upstream of it The discharge pipe should be at least one size larger than the main pipeline Version 2 0 June 2001 Page 53 of 264 Borders General Hospital NHS Trust on behalf of NHSScotland Property and Environment Forum 9 12 9 13 0 14 9 15 5 16 5 17 SHTM 2022 Part 1 Medical gas pipeline systems This discharge pipe line should be vented to atmosphere outside the building in an area where the discharge of oxygen nitrous oxide nitrous oxide oxygen mixture oxygen carbon dioxide mixture and nitric oxide or nitrogen will not contribute to a fire risk or cause injury to personnel It should be well clear of any openable window or air intake The ends of the discharge pipelines should be turned downwards to prevent the ingress of dirt and moisture and be placed and protected so that frost cannot form or be collected upon them Similar safety valve arrangements are required for installations supplied from liquid oxygen cylinder installations Manifold monitoring and indicating system The monitoring and indicating system should perform the following functions a overall manifold monitoring b manifold conditi
206. nt Forum 9 56 9 07 9 58 9 59 9 60 9 61 SHTM 2022 Part 1 Medical gas pipeline systems Plant status indicator unit In addition to the plant control indication there should be a plant status indicator panel which may be mounted on the plantroom wall or adjacent to either the pump starter unit or the plant control unit It should have a warning notice which complies with BS 5378 Part 3 1982 to indicate the presence of low voltage There should be indicators for each pump to show the following conditions green mains supply on yellow control circuit failed yellow motor tripped yellow for each individual safety device provided by the manufacturers yellow pump failure Alarm signal status unit The following indication of plant R be provided end oo 0 ODW Indication a green normal indicator oral b yellow plant fault conditions b d see 9 57 c yellow plant emer ency condition e see 9 57 d red pipeline plant failure e Red pipes pressure fault Condition ould be transmitted to the central alarm system Where rela d they should be normally energised relays which de V dc 50 mA Alternatively volt free normally closed contacts rated at 50 V dc 50 mA should be provided for transmission of conditions b to e to the alarm system The panel can be incorporated into the plant status indicator unit or be a separate unit within
207. nt and patient safety once commissioned medical gas pipelines are jubject to strict permit to work procedures and decommissioning a complete system is highly disruptive to patient care and introduces considerable risk Statutory obligations under the Pressure Systems Safety Regulations 2000 require the periodic testing of pressure safety devices It is not appropriate to test a medical gas pipeline system by either raising the line pressure regulator setting or manually unseating the relief valve Such action could result in failure of anaesthetic equipment and in the event of failure of the safety valve to re seat considerable gas loss and further hazard Medical gas pipeline line distribution systems should be provided with a pressure relief device downstream of the line pressure regulator connected by means of a three way cock so that the safety device can be exchanged for a certificated replacement in accordance with the frequency required by the Regulations Version 2 0 June 2001 Page 175 of 264 Borders General Hospital NHS Trust on behalf of NHSScotland Property and Environment Forum 14 1 14 2 14 3 14 4 14 5 14 6 14 7 14 8 14 9 SHTM 2022 Part 1 Medical gas pipeline systems 14 Accommodation Design and construction of plantrooms Location of plantrooms Cylinder gas liquid supply systems should not be located in the same room as medical air compressors PSA systems or vacuum plants M
208. ntrols The dryer control system should ensure that proportion to the compressed air usa system will become apparent when t is tested at 10 and 0 of the sy and performance of a dryer system since these items are critical t system The dryer contr te en n is operated in e eliectiveness of the control ffic of the compressor system ign flow Evidence of the reliability sought from manufacturers performance of the compressor ould include a dewpoint meter Dust filters There should k it filter downstream of the dryers to remove particles system demaad flow with air at 100 relative humidity at 35 C Activated carbon filter Duplex activated carbon filters should be installed upstream of the final bacterial filter Bacteria filters Duplex bacterial filters should be fitted upstream of the final pressure regulator with appropriate isolating valves The filters should provide particle removal to 0 01 mg m and a DOP penetration of less than 0 0001 Pressure control The pressure control should maintain the nominal pipeline pressure within limits given in Appendix 10 Duplex line pressure regulators should be Version 2 0 June 2001 Page 95 of 264 Borders General Hospital NHS Trust on behalf of NHSScotland Property and Environment Forum 7 49 7 46 1 41 1 48 1 49 SHTM 2022 Part 1 Medical gas pipeline systems provided with suitable isolating valves The regulators should be of the non rel
209. on The alarm control units status unit should be supplied from all individual plant r from a separate common supply Plant management Connections should be provided which allow monitoring of plant alarm conditions b to e and pump running for each compressor These connections should be volt free contacts normally closed for each condition having a minimum rating of 50 V dc 50 mA The building management system should not be used to control the plant Operating considerations Plant should be operated in accordance with the manufacturer s instructions and covered by a sound effective planned preventative maintenance PPM policy Version 2 0 June 2001 Page 102 of 264 Borders General Hospital NHS Trust on behalf of NHSScotland Property and Environment Forum 7 19 7 80 7 81 7 82 7 83 7 84 7 85 7 86 7 8 7 7 88 7 89 SHTM 2022 Part 1 Medical gas pipeline systems Synthetic air General This section gives technical details of the process and systems required to generate medical air from mixing gaseous oxygen and nitrogen derived from a cryogenic supply For the purposes of the Medicines Act it is considered that the synthetic air is manufactured on site for use on that site only in exactly the same way as for medical air derived from compressor plant The production of synthetic air implies a manufacturing process and as such the process should be subjected to the same
210. on behalf of NHSScotland Property and Environment Forum 2 34 2 39 2 36 2 3 2 38 2 39 2 40 2 41 2 42 SHTM 2022 Part 1 Medical gas pipeline systems The electricity supply to medical gas installations should be taken from separate circuits from a distribution board which is an essential board fed by the emergency generator system This should also apply to the medical gas alarms Reference should be made to SHTM 2011 Emergency electrical services Care is required when selecting pipeline routes to prevent the pipes coming into contact with electric cables and wiring and to minimise the risk of electric shock in the event of a fault on adjacent cables The final connection to any equipment for example alarm panels or control panels should be made via an unswitched fused connection unit In the event of power failure or interruption all systems should continue to operate exactly as before the interruption occurred For example except for automatic cycling compressors dryers pumps etcythe same compressor and dryer or vacuum pump set should be on liag and for manifold systems the same bank should be running accordance with EMC Directives to rej mains noise typically occurring in ho lant start up Reference should be made to SHTM 2014 Abatement of interference These systems should a systems which may be changeover delays atible with emergency electrical supply ther
211. on indication c overall supply plant indication ndic ors should have a d be capable of automatic All functions should be appropriately i design life of at least one year The reinstatement after restoration of p Manifold monitoring indicati essential electrical suppl n s stems should be on the Manifold control unit a green mains supply on indicator Manifold monit Each auto itold should be provided with monitoring to detect duty bank operating duty bank empty and standby bank operating standby bank below 10 capacity when the duty bank is empty Qa 9 5 p reserve bank below nominal 14 bar g for nitrous oxide and below 68 bar g pressure for other gases e pipeline pressure faults below 20 or above 20 of nominal pressure NOTE The emergency reserve manifold is monitored for condition 5 1 7d Version 2 0 June 2001 Page 54 of 264 Borders General Hospital NHS Trust on behalf of NHSScotland Property and Environment Forum 5 18 5 19 5 20 5 21 SHTM 2022 Part 1 Medical gas pipeline systems Manifold indicator unit There should be indicators to show the following conditions a for each automatic manifold i a green running indicator for each bank This should display when the bank is supplying gas irrespective of the pressure ii a yellow empty indicator for each bank when the running bank is empty and changeover has occurred ili a
212. on of the air intake t accordance with the contract specificati e compressors is in xil check the operation of the warning indicator unit m sygiem and the plant vacuum plants i check for the correct rotat urrent at full load li check for excessive v grati nvise iii check all autom turn valves and sensors v check the sem sti f vi check f op of all plant at its maximum continuous rating vil C ns and bypass valves iv check the oper tion of vith the contract specification vill ch ix checkthat the insulation resistance and effectiveness of earthing of all electrical items are in accordance with IEE regulations extant edition the accuracy of all vacuum gauges and thermometers x check that all plant operates with start up in the correct sequence when switched to the stand by power source xi check that the position of the vacuum discharge is in accordance with the contract specifications oxygen concentrator plant i check the operation of cycling systems for each sieve pair ii check the control system to regenerate the sieves in relation to pipeline demand Version 2 0 June 2001 Page 195 of 264 Borders General Hospital NHS Trust on behalf of NHSScotland Property and Environment Forum 15 74 15 75 15 76 SHTM 2022 Part 1 Medical gas pipeline systems iii check the operation of automatic changeover to standby molecular sie
213. or example cross connection the order in which the systems are tested may be decided on site by consultation between the contract supervising officer and the contractor s representative Version 2 0 June 2001 Page 186 of 264 Borders General Hospital NHS Trust on behalf of NHSScotland Property and Environment Forum 15 29 15 30 15 31 15 32 15 33 SHTM 2022 Part 1 Medical gas pipeline systems Modifications extensions or repairs to existing systems Where modifications extensions or repairs to existing systems are carried out the tests and the sequence of tests summarised in paragraph 15 14 should be followed as far as possible In any case great care must be taken to ensure that the principles of the tests are followed for example leakage tests should always be carried out before cross connection tests The permit to work system should always be followed whenever any work is carried out on an existing system The authorised person MGPS should act on behalf of the management and would not therefore be a member of the contractor s staff Whenever modifications or extensions are carried out it is always advisable to test both the existing system and the new system separately before the break in is made Existing systems should be tested to determine their performance and to identify any potential limitatigv7is which may arise as a result of modifications Where there is any do the cleanliness It is obvious
214. or each terminal Diversified flow unit I min Q l min In patient acute Ward units single and multi n 1 6 bedrooms 10 QW 10 Treatment rooms Each ward unit 1 w 1 Departments comprising 10 QD QW DE several day units ITU and CCU 10 QI 10 nB 1 6 Adult acute day care 100 20 T 1 QR 10 n 1 6 QR 10 n 1 6 Major treatment room 100 Endoscopy room 10 Recovery room Maternity department Delivery suite n 1 6 Normal delivery room QM 100 Abnormal delivery room Neonatal uni 10 QN 10 n 1 6 Operating room 100 QT 100 20 T 1 Anaesthetic room 10 QA 10 A 1 6 Version 2 0 June 2001 Page 40 of 264 Borders General Hospital NHS Trust on behalf of NHSScotland Property and Environment Forum 4 28 4 29 4 30 4 31 SHTM 2022 Part 1 Medical gas pipeline systems Legend for all tables n number of terminal units nB number of bed spaces W number of ward units T number of operating rooms or major treatment rooms A number of anaesthetic rooms S number of operating suites 1 operating room 1 anaesthetic room Q diversified flow QW diversified flow to ward units QD diversified flow to a department QI diversified flow to ITU or CCU QT diversified flow to operating room or major treatment room QA diversified flow to anaesthetic rooms QR diversified flow to recovery rooms QM diversified fl
215. or system a plant faults for each compressor i control circuit failed li motor tripped iii after cooler temperature high iv compressor temperature high v compressor failed to go on load vi activation of other safety devices supplied by the manufacturers Version 2 0 June 2001 Page 114 of 264 Borders General Hospital NHS Trust on behalf of NHSScotland Property and Environment Forum 8 22 8 23 8 24 SHTM 2022 Part 1 Medical gas pipeline systems b plant faults for each dryer unit i dryness failure dewpoint meter gt 26 C ii pressure fault c plant emergency i receiver pressure 0 5 bar g below the standby cut in pressure ii receiver pressure 0 5 bar g above cut out pressure iii dryness above 0 51 mg l dewpoint at 26 C at atmospheric pressure d pressure fault cylinder reserve i pressure in duty bank below 50 of normal cylinder pressure e pressure fault pipeline i low pipeline pressure ii high pipeline pressure Plant status indicator unit In addition to the plant control indican ould be a plant status indicator panel which may be mo the plantroom wall or adjacent to either the compressor starter unit or Pot control unit It should have a warning notice which complieSeyi 78 to indicate the presence of low voltage There should be indicatars for efch compressor to show the following conditions trol uit failed oa
216. or these termina given in Table 23 eratewvat the specified design flow ed leaks It must then be verified ut tne installation that at the normal e pressure does not fall below the values 15 69 This test requires th the desi flow is corrected for the density of the test gas ust be placed where the downstream flow could be at least equal to the total flow through the leak These leaks may be placed at terminal units AVSUs or NIST connectors as appropriate This is not likely to be the end of the branch e approximately 20 25 of the terminal units distributed throughout the system must be tested with the device described in Appendix 3 to measure the pressure at the specified flow 15 70 For large vacuum systems the specified design flow may be set by the procedure given in Appendix 7 With the system running at the design flow it must then be verified at representative terminal units throughout the installation that at the normal flow for these terminal units 40 l min the pressure drop does not exceed the value given in Table 23 It may be necessary to incorporate an additional uncalibrated leak at the plant test point to stabilise the vacuum level to 450 mm Hg at the plant pipeline interface Version 2 0 June 2001 Page 193 of 264 Borders General Hospital NHS Trust on behalf of NHSScotland Property and Environment Forum 15 71 15 72 15 73 SHTM 2022 Part 1 Medical gas pipeline systems Fo
217. ould be provided for the neonatal intensive care unit ITU and theatres if provided to control one of each pair of terminal units installed This will ensure continuity of gas supply if the need arises for urgent servicing or repair of terminal units AVSUs for nitric oxide systems will not require N spades They will be of stainless steel constr lockable box with emergency access connectors or blanking enclosed ina remises which may Where it is impracticable rminal units for servicing since nitric oxide and nitrogen dioxie are tox nd the check valves typically included tight Pipeline distri The flows in clinical use are modest and pressure loss is not a critical desi The installation will generally comprise 6 mm stainless steel tubing stalled by means of orbital welding using an argon shield Iso be used during pressure testing and purging prior to commissioning Identification The pipeline installation should bear identification generally in accordance with this SHTM Green has now been accepted as the identification colour Alarm systems The main alarm system indicator panel should be located in one of the critical care areas where as stated in the operational policy for the hospital staff responsible for cylinder management can be contacted Repeater alarm panel s should be located elsewhere for example the neonatal intensive care unit Version 2 0 June 2001 Page 143 of 264 Borders General
218. ould be provided under the air compressor contract Provision of interceptor tanks may be provided under either the building contract or the air compressor contract as appropriate Version 2 0 June 2001 Page 96 of 264 Borders General Hospital NHS Trust on behalf of NHSScotland Property and Environment Forum 7 50 7 91 7 92 7 53 7 04 SHTM 2022 Part 1 Medical gas pipeline systems Non return valves Non return valves are required to prevent backflow of the air supply in certain situations These valves should be located as follows a between the compressor and the receiver but downstream of any flexible connector b downstream of the dust filter on the dryer c upstream of the emergency cylinder reserve connection in the pipeline connecting the plant to the pipeline distribution system to prevent back feeding this plant d upstream of any inlet point which may be used to feed the system in an emergency e downstream of the emergency cylinder manifold regulators Isolating valves Isolating valves should be provided downstr turn valves and upstream of for example the connectign of th emergency reserve manifold Isolating valves should be rder to facilitate maintenance or replacement of plaat i O ould be located in the positions n of Components such as receivers gulators and filters There should also plant upstream of the non return valve ncy cylinder reserve Manually operat
219. overload tripped 0229 5 wp g yellow compressor a green b yellow ault c yellow pyessure fault Version 2 0 June 2001 Page 101 of 264 Borders General Hospital NHS Trust on behalf of NHSScotland Property and Environment Forum 1 12 7 13 7 74 7 79 7 16 7 01 7 18 SHTM 2022 Part 1 Medical gas pipeline systems Alarm signal status unit An alarm signal status unit should be provided as part of the control system lt should display the following conditions Indication Legend a green normal normal b yellow plant fault conditions b g see 7 70 c see 7 71 c yellow plant emergency low reservoir pressure high moisture that is condition b see 7 71 d yellow reserve low emergency reserve banks low lt 50 e red pipeline pressure fault pressure Conditions b to e should be transmitted t Where relays are used they should be norm energise under fault conditions with c cts V dc 50 mA ed relays which de ving a minimum rating of 50 cts rated at 50 V dc 50 mA itions b to e to the alarm Alternatively volt free normally clos should be provided for trans system C O The panel can be incor unit within the plag monitored for oe system fault l together wiih the o the plant indicator unit or be a separate ted separately the cabling should be sropriate alarm conditi
220. ow to maternity suite QN diversified flow to neonatal unit QB diversified flow to baby bed space QDent diversified flow to dental departme QWS diversified flow to equipment worksh QP diversified flow to plaster roo Operating departments The diversified flow for opera ents is based on 100 l min required for the oxygen f operating room and an unlikely that an oxygen should be able to pass 100 l min It is e administered simultaneously in several operating roo in for the remainder For anae ic rooms each terminal unit should be capable of passing 10 l min b dl flow likely to be used is 6 l min The diversified flow is based on 1 in for the first room and 6 l min for the remainder since it is ll anaesthetic rooms may be in use simultaneously Recovery is considered jn a similar way since again it is possible that all bed spaces may be in use simultaneously To obtain the flow to each operating suite add the flows to the operating room and anaesthetic room that is 110 l min The need for an oxygen flush in anaesthetic rooms should be taken into account in the design Assume one terminal unit in each department is in use with oxygen flush at any one time irrespective of the overall number of operating suites Major treatment rooms A amp E theatres surgery and maternity operating departments should be treated as operating departments Version 2 0 June 2001 Page 41 of 264 Borders General Hospital NHS Trust on
221. pe recommended for compressed air systems It is also possible to provide a combined medical air PSA plant Generally the gompressed air requirement per litre of product gas Is of the order 4 1 and ult the compressor A vacuum pump may be required as if provided is utilised during the adso pumps may be of any type as for not generally be practicable tq use medical vacuum plant ystem The vacuum pump eration process Vacuum medical vacuum system It will led pumps nor to utilise the rs Compressor noise the plant oul wgot normally exceed the following values Reciprocatin Screw Vane Power 85 dBA 76 dBA 76dBA 7 5 kW 89 dBA 78 dBA 76 dBA 7 6 15 kW 93 dBA 80 dBA 79 dBA 15 1 22 kW 97 dBA 92 dBA 90 dBA 22 1 60 kW In noise sensitive areas an acoustic enclosure should be included in the purchase specification for all compressors Such an enclosure should produce a reduction of at least 10 dBA in the free field noise level at 1 m Molecular sieves Duplex molecular sieves should be provided in pairs to permit continuous generation of oxygen One of the pairs of duplex sieves will be in the adsorbing stage whilst the other regenerates Version 2 0 June 2001 Page 82 of 264 Borders General Hospital NHS Trust on behalf of NHSScotland Property and Environment Forum 6 105 6 106 6 107 6 108 6 109 6 110 SHTM 2022 Part 1 Medical gas pipeline systems Dryers Air dryers of the
222. peline Total System Tests Form B7b Sheet of Sheets Hospital Scheme File Number Date Functional Test NIST Connectors in accordance with the Contract Specifications and paragraphs 15 66 15 67 System NIST Gas Location or Room Gas Specificity Self Sealing Identification Number Pass Fail Adequate Inadequate Contractor s Represe haw Status W Signed Date v Name Contract Supervising Officer Status Signed Date Name Witnessed on behalf of By Status Signed Date Version 2 0 June 2001 Page 227 of 264 Borders General Hospital NHS Trust on behalf of NHSScotland Property and Environment Forum SHTM 2022 Part 1 Medical gas pipeline systems Medical Gas Pipeline Total System Tests Form B8 Sheet of Sheets Hospital Scheme File Number Date Design Flow Performance Tests in accordance with paragraphs 15 68 15 71 System System design flow Terminal Unit test flow l min Test Pressure Minimum gauge pressure alowed ___ kPa a a Terminal Room an Terminal Room ee Terminal Room ca Unit No No Met V Unit No No Met V Unit No No Met V Status Date Contract Supervising Officer Status Date Witnessed on behalf of By Status Signed Date Version 2 0 June 2001 Page 228 of 264 Borders General Hospital NHS Trust on behalf of NHSScotland Property and Environment Forum Medical Gas Pipeline Total System Tests Hospital File Number Source of Supply SHTM 2022 Part 1 M
223. pen probe or flow meter into downstream terminal units Results Record the results on Form B5 There should be no pressure or vacuum decrease upstream of the valve under test Zoning of AVSUs The tests specified in paragraphs 15 54 15 57 must have been completed satisfactorily Version 2 0 June 2001 Page 210 of 264 Borders General Hospital NHS Trust on behalf of NHSScotland Property and Environment Forum 15 167 15 168 15 169 15 170 15 171 15 172 SHTM 2022 Part 1 Medical gas pipeline systems Procedure The procedure for the test is as follows a connect a pressure measuring device to the system The system should be at pipeline distribution pressure and all AVSUs except the one under test should be open b decrease the pressure in the pipeline downstream of the AVSU under test to about 1 bar g or 200 mm Hg 27 kPa for vacuum Note the number of terminal units controlled by the AVSU and check that they are all at the test pressure of 1 bar g or 200 mm Hg 27 kPa c as test probes are inserted into terminal units in the section under test there may be loss of pressure or vacuum If necessary re adjust the test pressure d check the AVSU for leakage into the environ t Results Record the results on Form B5 Open the A tO eve pipeline distribution pressure and proceed to n xt AVSU h During the test it will be necessa the supply system connected to maintain pressures
224. perbaric oxygen chambers for clinical purposes should be supplied from a separate branch Typical flows for one person chambers are as shown in Table 5 Table 5 Gas flow hyperbaric chambers Max time for one Total consumption for Consumption for each complete treatment max treatment time additional minute O atmosphere and litres ymin recirculation e on open circuit 2 hours 30 000 250 e on recirculation 2 hours 7 250 40 Oz only no 2 hours 30 000 250 recirculation O delivery by built in 2 hours v 10 breathing mask and overboard pump O delivery by built in 2 hours 60 breathing hood and overboard pump Note 1 The flows for a recirculati recirculation throughout designed for open circui 2 Clinical practice m necessary to s consideration 3 Some hyoerbaric consum e the standard method of operation is gt is recommended that the pipeline should be ensure adequate flow under all conditions e usion of air during the treatment it may also be ohir i nlikely event of an oxygen convulsion Therefore oulg Nman to the provision of medical air nambers use air as a buffer and considerably less oxygen is gt of the manufacturer should be sought Version 2 0 June 2001 Page 39 of 264 Borders General Hospital NHS Trust on behalf of NHSScotland Property and Environment Forum SHTM 2022 Part 1 Medical gas pipeline systems Table 6 Oxygen diversified flows Department Design flow f
225. pital NHS Trust on behalf of NHSScotland Property and Environment Forum 15 50 15 51 15 52 15 53 15 54 15 55 15 56 SHTM 2022 Part 1 Medical gas pipeline systems Closure of area valve service units For pressurised systems the system upstream of the closed valve under test must be at pipeline distribution pressure and the downstream line should be evacuated by using an opened flow meter or probe This upstream pressure must be recorded and there should be no pressure decrease upstream from the valve over a period of 15 minutes In the event of loss of pressure it will be necessary to identify the faulty AVSU This may be accomplished by introducing a pressure to about 1 bar g after AVSUs and checking for increased pressure For vacuum systems the systems on the supply plant side of the closed valve must be at pipeline distribution pressure and the terminal unit side should be at atmospheric pressure This upstream pressure must be recorded and there should be no loss of vacuum upstream of the valve over a period of time typically 30 minutes AVSU This may be accomplished by introdu um of about 200 mm Hg after AVSUs and checking for in vacuum Zoning of area valve service un erminal unit identification heck of all AVSUs must be made ipeline under pressure is labelled and nded in the design see opposite The labelling of each termin unit mist be checked to ensure that it is correct and is in acco
226. ply on b yellow control circuit failed c yellow overload tripped d yellow after cooler temperature high e yellow compressor temperature high f yellow for each individual safety device provided by the manufacturers g yellow compressor failure Version 2 0 June 2001 Page 86 of 264 Borders General Hospital NHS Trust on behalf of NHSScotland Property and Environment Forum 6 122 6 123 6 124 6 125 6 126 6 127 6 128 SHTM 2022 Part 1 Medical gas pipeline systems There should be indicators for each molecular sieve dryer system to show the following green mains supply on yellow oxygen concentration fault Og yellow pressure fault d yellow dryness fault When the standby dryer is in operation conditions b and c paragraph 6 122 should be transmitted as a plant emergency to either the alarm system or to the plant alarm signal status unit Alarm signal status unit An alarm signal status unit should be provided a It should display the following conditions rt of the control system Indication Lege a green normal a b yellow plant fault nditi b f see 6 121 C cor ition g see 6 121 d ergency reserve banks low lt 50 e pipeline fault f pressure fault Condition ould be transmitted to the central alarm system Where rela d they should be normally energised relays which de energise unde
227. pm Insert actual number of samples tested and lo ation For PSA Systems only CO2 lt 300 ppm Parameter Specification Sample f v Contractor s Represent ive Status W Signed y Date Name Contract Supervising Officer Status Signed Date Name Witnessed on behalf of By Status Signed Date Version 2 0 June 2001 Page 234 of 264 Borders General Hospital NHS Trust on behalf of NHSScotland Property and Environment Forum SHTM 2022 Part 1 Medical gas pipeline systems Medical Gas Pipeline Total System Tests Form B15 Sheet of Hospital Scheme File Number Date Gas Identification This is to certify that the gas at all terminal units has been tested in accordance with paragraphs 15 106 15 110 as follows Piped Supply Test For Specification Result Limit Oxygen Not less than 99 0 NOU N20 2 O NO Not less than 98 NO0 No Tops y Medical Air o ri mo AK7 Surgical Air o ENW No o y 7o Vacuum ECON N e All are v v Contractor s pres ive Status Signed Date Name Contract Supervising Officer Status Signed Date Name Witnessed on behalf of By Status Signed Date Version 2 0 June 2001 Page 235 of 264 Borders General Hospital NHS Trust on behalf of NHSScotland Property and Environment Forum SHTM 2022 Part 1 Medical gas pipeline systems Appendix 2 Gas pressure variation with temperature General I Tests are specified for leakage of the pipeline carcass and
228. ppropriate standards and authorised by design authorities There must be no modification to the design of any part of the VIE system without written authorisation from the gas supplier Records should be kept of design installation maintenance and of any modifications which are carried out by the hospital and the gas supplier Version 2 0 June 2001 Page 65 of 264 Borders General Hospital NHS Trust on behalf of NHSScotland Property and Environment Forum 6 26 6 27 6 28 6 29 6 30 SHTM 2022 Part 1 Medical gas pipeline systems Control panel The VIE medical control panel is designed to accept a supply of gaseous oxygen from the VIE at 10 5 bar g or from the standby manifold at 8 5 bar g and to reduce the pressure to 4 2 bar g in the oxygen pipeline distribution system Sites for liquid oxygen storage The VIE should be located inside a fenced compound which may also house the control panel and the standby manifold The location should be acceptable to both the gas supplier and the hospital and should be exclusively reserved for the storage of liquid oxygen and other non flammable cryogenic liquids The vessel should not be located inside a building It may be necessary to comply with local authority planning constraints in some areas The site chosen should comply with the safety distances in the British Compressed Gases Assg fiation Code of Practice 19 Bulk Liquid Oxygen Storage at Users Premis
229. pproximately 4 m long by cylinders is 1 8 k adds All medical gas manifolds may be the same room Additional date separate storage racks for igned along the lines of those on the manifolds but the store 4 cylindegs May be closer together Racks should conform to BS EN openings equivalent to at least 1 5 of the total area of the walls and room should be provided For example given a manifold room 5 0 x 4 0 x 2 4 m with a total area of the walls and ceiling of 63 2 m the total free open area for ventilation required is 1 m The aspirated air inlets should if possible be located externally and should vent to a safe area away from ventilation plant intakes etc However they should not be taken as an alternative to the provision of an adequate air supply for cooling purposes All vents should be vermin bird proot Version 2 0 June 2001 Page 177 of 264 Borders General Hospital NHS Trust on behalf of NHSScotland Property and Environment Forum 14 17 14 18 14 19 14 20 14 21 14 22 14 23 SHTM 2022 Part 1 Medical gas pipeline systems PSA and medical air compressors liberate under maximum flow conditions considerable heat Moreover these plants aspirate air for breathing purposes Generous natural ventilation should be provided The ambient temperature of manifold rooms and plantrooms should be maintained within the range of 10 C to 40 C The ventilation rates should ensure that the plantroom temp
230. purposes and may be provided occasionally for analgesic purposes In all cases each terminal unit should be capable of passing 15 l min but in practice the flow is unlikely to exceed 6 l min Therefore for operating rooms and anaesthetic rooms allow 15 l min for the first room and 6 l min for the remainder Version 2 0 June 2001 Page 42 of 264 Borders General Hospital NHS Trust on behalf of NHSScotland Property and Environment Forum 4 42 4 43 4 44 4 45 4 46 4 47 SHTM 2022 Part 1 Medical gas pipeline systems lt must be assumed that where nitrous oxide terminal units are provided they may all be in use simultaneously Design and diversified flows for nitrous oxide are given in Table 7 Table 7 Nitrous oxide diversified flows Department Design flow for each terminal Diversified flow Ath rin All departments 15 Q 15 nB 1 6 nB number of bed spaces or number of rooms as appropriate Nitrous oxide oxygen mixture remainder since it is possible that administered at all bed spaces whe s is based on 275 min for the first bed ainder of which only 50 will be in r ch oft The diversified flow in d space and 20 l min for use simultaneously Design and di ows for nitrous oxide oxygen mixtures are given in Table 8 e oxygen mixtures design and diversified flows Department Design flow for each terminal Diversified flow als Qin Delivery rooms 275 QM 275 4 20 nB
231. quirements under all conditions due for example to variations in wind direction and pressure which may result in excessive suction pressure Some AGSS have been installed in which the disposal system discharges into the mechanical ventilation system such systems may be described as semi passive or assisted passive systems The ventilation system provides the motive force to remove the pollution These systems are not recommended because like passive systems their performance is not reliable and they cannot meet specified safety requirements under all conditions Where passive and assisted passive systems ingcalled an assessment of their efficiency should be carried out as d scr Operational management part 2 of this SHTM Considera jon s d be given to replacing these systems with an AG ich Camplies with BS EN 737 and BS 740 General design requiremen not be used to remove waste edicalg atuum system is designed to provide a m Hg 63 kPa at the terminal unit see Chapter The medical vacuum sy anaesthetic gases Th suction pressure of 40 9 If the patient would almost ce All safety devices should fail safe AGSS are in contact with the patient s expired breath and hence there is the potential for bacteriological contamination The materials should be reasonably resistant to corrosion and should withstand cleaning disinfection or sterilization as appropriate It is recommended that the transfer system an
232. r fault conditions with contacts having a minimum rating of 50 V dc 50 mA Alternatively volt free normally closed contacts rated at 50 Vdc 50 mA should be provided for transmission of conditions b to f to the alarm system The panel can be incorporated into the plant indicator unit or be a separate unit within the plantroom If mounted separately the cabling should be monitored for open short circuit In the event of such a cabling fault a red system fault lamp should be illuminated on the alarm signal status unit together with the appropriate alarm condition The alarm signal status unit should be supplied from all individual plant control units or from a separate common supply Version 2 0 June 2001 Page 87 of 264 Borders General Hospital NHS Trust on behalf of NHSScotland Property and Environment Forum 6 129 SHTM 2022 Part 1 Medical gas pipeline systems Plant management Connections should be provided which allow monitoring but not control of the plant operation For example compressor on off on load unloaded molecular sieves on or off These connections should be used to provide input to the hospital energy management and building management systems Version 2 0 June 2001 Page 88 of 264 Borders General Hospital NHS Trust on behalf of NHSScotland Property and Environment Forum 7 1 7 2 7 3 7 4 7 9 7 6 SHTM 2022 Part 1 Medical gas pipeline systems 7
233. r mixtures of oxygen nitrous oxide 50 v v each terminal unit must be tested to ensure that a peak flow of 275 I min for 5 seconds can be achieved with a minimum pressure of 310 kPa 3 1 bar g This is the minimum pressure for satisfactory operation of demand valve regulators This is in addition to the total system flow test Functional tests of supply systems For all systems prior to carrying out any tests check that the provision is in accordance with Table 2 All supply systems must be tested for normal and emergency operation according to the manufacturers manuals and contract specifications Check lists must be written for the appropriate functions of all the items of plant in the installation Particular attention should be paid to the following a manifold installations test gas may be usedgror the following checks Nee ayre same ime v nifolas operate at the gaSwmiader must be used to trolled leak allows observation of NOTE The appropriate alarm functions maygbe i check that each half of all auto specified pressures A stand pressurise the manifold a the operating pressure ii check the operation o ress valves regulating valves and non return iii check the operation of ay heaters where fitted iv check t can deliver design flow rate v check of the emergency manifold lant operates with start up in the correct sequence d to the stand by power source b
234. rd 2 1998 With pressure in one system to ensure that each AVS lyg The AVSU un be closed all other AVSUs should be open s the system upstream of the valve should be at ressure and the downstream section should be de pressurised about 1 bar All downstream terminal units should be checked for pressure avid the results recorded During the test the recorded pressure of 1 bar or thereabouts will fall depending upon the number of terminal units controlled and it may be necessary to top up the pressure to complete the test NOTE Where pneumatically activated pendant fittings are installed a check should be made to ensure that the power source of medical air has been taken from the correct AVSU Version 2 0 June 2001 Page 191 of 264 Borders General Hospital NHS Trust on behalf of NHSScotland Property and Environment Forum 15 57 15 58 15 59 15 60 15 61 15 62 15 63 15 64 SHTM 2022 Part 1 Medical gas pipeline systems For vacuum systems the downstream vacuum should be about 200 mm Hg 27 kPa and all downstream terminal units should be checked for increase in vacuum As for pressurised systems it may be necessary to top up the vacuum to complete the test NOTE A downstream pressure or vacuum is required to positively identify terminal units controlled and to discount the effect of a leaking terminal unit if the pressure were zero Similar valve closure and zoning tests should
235. re given in the appropriate Health Building Notes Scottish Hospital Planning Notes and Design Guides Version 2 0 June 2001 Page 24 of 264 Borders General Hospital NHS Trust on behalf of NHSScotland Property and Environment Forum 3 3 8 3 9 3 10 3 11 3 12 3 13 SHTM 2022 Part 1 Medical gas pipeline systems NOTE Reference should be made to EL 96 33 covering publication advice on the implementation of the Health amp Safety Commission s Occupational Exposure Standards for Anaesthetic Agents published by the Department of Health March 1996 Further guidance is given in Anaesthetic agents Controlling exposure under COSHH prepared by the Health Services Advisory Committee ISBN 0 7176 1043 8 The terminal unit AGS is specified in BS EN 737 4 1998 AGSS are covered in Chapter 10 If nitrous oxide is provided in the equipment service room or workshop an appropriate AGSS must also be provided Medical quality compressed air should be available to at least one workstation in the equipment service room and workshop Terminal units in accordance with BS 5682 1998 should be provida The supply should be Where an anaesthetic equipment testing areis idd it will be calibration of s terminal units will be Id be used for testing f the medical gas the terminal onfusion TEST PANEL GAS anaesthetic equipment A full range required but wherever possible units must be clea
236. red The filters should comply with BS ISO 5011 2000 and be either dry medium filters or grade CA paper element filters Version 2 0 June 2001 Page 89 of 264 Borders General Hospital NHS Trust on behalf of NHSScotland Property and Environment Forum 1 1 7 8 7 9 7 10 7 117 7 12 SHTM 2022 Part 1 Medical gas pipeline systems Compressor noise The noise level produced by the compressors will increase with the capacity of the supply system The maximum free field noise level for unsilenced compressed air plant at 1m from the plant varies with the type and power of the plant but should not normally exceed the following values Reciprocating Screw Vane Power 85 dBA 76 dBA 76dBA 0 7 5 kW 89 dBA 78 dBA 76 dBA 7 6 15 kW 93 dBA 80 dBA 79 dBA 15 1 22 kW 97 dBA 92 dBA 90 dBA 22 1 60 kW In noise sensitive areas an acoustic enclosure should be included in the purchase specification for all compressors Such ag enclosure should produce a reduction of at least 10 dBA in the fr noise level at 1 m Air intake caved to minimise contamination tsa discharge from vacuum ms AGSS and ventilation eally air intakes should be nd level The air intake for a compressor shoul from internal combustion engine exh systems anaesthetic gas scaven systems or other sources of conta located at levels of at least 5 Compressor types There are many market Three f compressor currently available
237. rements for ventilators and nebulisers Ventilator type Pressure kPa Flow l min free air Anaesthesia typically gas driven 300 700 Pneumatically driven electronically controlled nominal 400 ventilators use up to 80 l min 20 I min continuous Intensive therapy 300 700 180 peak Electronically controlled nominal 40 80 continuous Gas powered 0 peak 40 continuous 10 Neonatal electronically controlled 300 700 Gas driven n Nebulisers Notes 1 Itis strongly recommended that since the blenders only differential pressure for tors ar not connected to the 700 kPa system ily with a tolerance of about 10 on the 4 56 4 57 a a flow liming device is provided to protect the medical air system in the event of failure of any downstream component b anon return valve is incorporated to protect the system integrity 4 58 The flow requirements should be ascertained and taken into account prior to the installation of the equipment In patient accommodation 4 59 In ward areas and treatment rooms all terminal units should be capable of passing 20 l min although typically 10 l min will be required 4 60 The diversified flow to each six bed room is calculated on the basis of numbers of terminal units and that only 33 of the flow at 10 l min will be Version 2 0 June 2001 Page 45 of 264 Borders General Hospital NHS Trust on behalf of NHSScotland Property and Environment Forum 4 61 4 62 4 63 4
238. reshat the pipelines and the AVSUs pecification and BS 1710 and ed in accordance with BS tra lf the labelling and marking is corect complete Form B1 Table 26 Summary of tests required on pipeline carcass Test order Description Form 1 Labelling and marking B1 2 Sleeving and supports B1 3 Leakage B1 4 Cross connection B1 Version 2 0 June 2001 Page 207 of 264 Borders General Hospital NHS Trust on behalf of NHSScotland Property and Environment Forum SHTM 2022 Part 1 Medical gas pipeline systems Table 27 Summary of tests required on pipeline system Test order form Description 5 Leakage from total compressed into total vacuum system B3 6 Leakage into total vacuum system B4 7 Closure of AVSU B5 8 Zoning of AVSU B5 9 Cross connection B6 10 Flow and pressure drop at terminal units B7A 11 Mechanical functions of terminal units B7A 12 Gas specifity of terminal units B7A 13 NIST connectors B7A 14 Performance tests of the pipeline system B8 15 Functional tests of supply system B9 16 Pressure safety valves B10 17 Warning systems B11 18 Verification of drawin B12 19 Filling with medical al B13 20 Purging and filling Spe wific gases B13 21 Quality B14 22 Gas i B15 Leakage 15 150 Ifithas been n purpose of this teas Alternativ provided n tv to link the carcasses to form a single system for the are Must be taken to ensure the links are removed may be carried out on sections of the pipe
239. ressure For vacuum to indicate that the vacuum in the pipeline serving OW Red Yes the department has fallen 20 below normal working vacuum va Version 2 0 June 2001 Page 160 of 264 Borders General Hospital NHS Trust on behalf of NHSScotland Property and Environment Forum 13 1 13 2 13 3 13 4 13 5 13 6 13 7 SHTM 2022 Part 1 Medical gas pipeline systems 13 Pipeline installation Accommodation of pipes Generally MGPS should be kept away from areas where they may be subject to any of the following mechanical damage chemical damage excessive heat a 9 5 p splashing dripping or permanent contact with oil grease or bituminous compounds electrical sparks etc ould have event of any service ducts or voids containing medical g adequate ventilation to prevent gas concentr leakage occurring eS Exposed pipelines should not be afts kitchens laundries boiler houses generator rooms inc rooms storage rooms designed to house combustible materia or other fire risk area Where pipelines in hazardous ar navoidable they should be enclosed in osed ducts with other services such as steam atems they should be inspected regularly as Pipelines shold be protected from the possibility of lightning strikes Pipelines should be suitably protected where there is a possibility of physical damage for example from the passage of trolleys Wherever practicable a clearance of at
240. ressure regulator has a control tolerance of 4 the maxi conditions is 460 kPa The pressure relations intended as a guide to It is important Ny achieved s should be checked to ensure that any extension or modification compatible with the existing systems Pressure regulators which require a continuous bleed to control pressure are not recommended because of the wastage of gas or air The pressure losses across a terminal unit and across a pendant which includes a terminal unit are shown in Table 1 Pressure regulation This is derived from BS 5682 amendment 5419 1987 and has been modified to include surgical air with flows at 350 I min Refer to BS 5682 1998 Pressure regulation for surgical air 700 kPa systems Compressed air for surgical tools should be available at the terminal unit at a pressure of 700 kPa at the required maximum flow of 350 I min To avoid over pressurisation at lower flows it will be necessary to provide a pressure control unit upstream of the terminal unit The pressure loss of the hose Version 2 0 June 2001 Page 254 of 264 Borders General Hospital NHS Trust on behalf of NHSScotland Property and Environment Forum 10 11 12 13 14 10 SHTM 2022 Part 1 Medical gas pipeline systems connection between surgical tools and the terminal unit should be taken into account When designing the upstream pipeline distribution system the pipeline pressure loss allowance of
241. ric oxide nitrous oxide and nitrous oxide oxygen mixture The nominal gas concentration at the specific terminal units is given in Table 25 Vacuum must be identified by observation of suction at the terminal units Version 2 0 June 2001 Page 202 of 264 Borders General Hospital NHS Trust on behalf of NHSScotland Property and Environment Forum 15 111 15 112 15 113 15 114 SHTM 2022 Part 1 Medical gas pipeline systems Table 25 Gas concentrations for identification purposes Medical gas Oxygen concentration Nitrous oxide concentration v v v v O2 minimum 99 0 n a Medical and surgical air 21 0 1 0 n a NO 0 minimum 98 0 N2O O2 50 50 50 0 2 0 50 0 2 0 Notes 1 The tolerance of the measuring instrument should be allowed in addition 2 For oxygen concentrator plant PSA supplied system the minimum concentration must be 94 oxygen 3 For bulk liquid liquid or gaseous cylinder suppye in accordance with the European Pharmacs requirements d systems this must be Ph Eur Requirements before a MG ken into use General iate persons must certify in writing that in paragraphs 15 37 15 78 and 15 86 d that all systems comply with the t include certification that all drawings and manuals e been supplied and as fitted drawings are Before a system is use the tests and procedur 15 110 have bee requirements required by the correct It must be d tnat the A
242. rly labelled TERMINAL UNITS CON Where gas mixers blenders ar to be tested it will be necessary to provide the appropriate g y be provided either from the MGPS or from cylinders a fora horizontal array when viewed from the front left to right oxygen nitrous oxide nitrous oxide oxygen mixture 50 v v medical air 4 bar surgical air 7 bar vacuum anaesthetic gas scavenging nitric oxide oxygen carbon dioxide mixture O2 N20 N20 0 MA 4 SA 7 VAC AGS NO O2 CO2 b fora vertical array with oxygen at the top and in the sequence as fora horizontal array In many cases a vertical array is impracticable and a more convenient arrangement will comprise a number of rows for example Oo N O and or N 0 0 gt MA 4 SA 7 VAC AGS NO O COs Version 2 0 June 2001 Page 25 of 264 Borders General Hospital NHS Trust on behalf of NHSScotland Property and Environment Forum 3 14 3 15 3 16 SHTM 2022 Part 1 Medical gas pipeline systems c foracircular array for example where terminal units are installed on the under surface of a pendant with the sequence as for a horizontal array in a clockwise direction when viewed from below The AGS terminal unit may occupy the centre of such an array Mounting heights for terminal units should be between 900 mm and 1400 mm above finished floor level FFL when installed on walls or similar vertical surfaces When installed in pendants or similar terminal uni
243. rogen is used as the inert gas shield and all terminal units should be tested to ensure that the systems have been adequately purged For oxygen systems and nitrous oxide oxygen an oxygen analyser must be used to ensure that the oxygen concentration is not less than that given in Tables 24 or 25 For nitrous oxide systems nitrogen has been used as the inert gas and an instrument based on thermal conductivity or an infra red meter must be used to check that the system has been adequately purged at every terminal unit Pipeline odour This test must be carried out as the final test A representative sample of terminal units on all systems must be checked to ensure that there is no taste or odour This check i IS sophie to ensure at no contamination has example flexible hose asse indicated that the quantitig be tested at every terminal on all MGPS This would include al terminal units whether on a new installation or a ion and a representative sample of terminal units on hich may have been affected by the work All systems n filled with the specific gas according to paragraph 15 86 do not connect any system to medical equipment The composition of all compressed gases must be positively identified This can be accomplished using an oxygen analyser for oxygen nitrous oxide oxygen and air and a thermal conductivity or infra red meter for nitrous oxide A sampling procedure must be used which will minimise pollution from nit
244. s Air receivers should comply with BS 5169 19 supplied with test certificates The min wter capacity of the receivers should be 50 of the compressor o ute stated in terms of free air delivered at normal working pr eceivers should also be fitted with an automatic drain To facilitate the statutory 4 valved air receivers or mode only in order to there should be either two suitably ngement for use in manual operating uption to the supply Air treatment General ter the compressed air system from three sources the atmosphere jhe compressor and the pipeline distribution system Each potential sourve must be taken into account when specifying the type and location of air treatment equipment Filtration equipment may include pre filters coalescing filters carbon filters particulate filters and any other additional filtration equipment necessary to provide the appropriate quality Solid contaminants Dirt particles in the environment cover a wide range of sizes but approximately 80 are less than 0 2 um and are therefore not removed by the intake filter to the compressor Although particles smaller than 40 um are unlikely to cause mechanical damage a 5 um intake filter is preferred to avoid blockage of internal air oil separators Version 2 0 June 2001 Page 93 of 264 Borders General Hospital NHS Trust on behalf of NHSScotland Property and Environment Forum 1 21 7 28 7 29 7 30 7 31 7 32 7 33 7
245. s BO Carcass tests Labelling and marking B1 Sleeving and supports B1 Leakage test Cross connection System tests Leakage test Vacuum leakage tg B4 AVSUs clos fang B5 Cross connections gt B6 Functiona minal units and ilST connectors B7 Design flow p rformance test B8 sources of supply B9 Pressure safety valves B10 Warning systems B11 Verification of drawings B12 Purging and filling B13 Quality B14 Gas identification B15 Version 2 0 June 2001 Page218of 264 Borders General Hospital NHS Trust on behalf of NHSScotland Property and Environment Forum SHTM 2022 Part 1 Medical gas pipeline systems Medical Gas Pipeline Carcass Tests Form BO Sheet of Sheets Hospital Scheme File Number Date Summary of tests This is to certify that the following tests have been carried out System Form Test Carried Out Satisfactorily Carcass tests Labelling and Marking Sleeving and Supports Leakage Test Cross Connection Tests OJ WD WW W NO TN ETTIRA System Tests Leakage Test Vacuum Leakage Test Area Valve Service Units Closure and Zoning Tests Cross connection Test Functional Tests of Terminal Units and NIS Connectors Design Flow Performance Tests Sources of Supply Pressure Safety Valves Warning Systems Verification of Drawings B12 B13 Purging and Filling Quality l Gas Identification O B15 Construction L keg moved Responsible Offits B11
246. s material to vulnerable patients Micro organisms can penetrate a bacteria filt aterial is wet Therefore it is essential that the dryness of supplied to a bacteria filter is checked regularly at least e onths at the test point using the test equipment specifici The following general inf tio required in order to design an MGPS a schedule of provisidg of tern jnal units b design flow n re requirements at each terminal unit c diversified section of the pipeline system Guidance olh eriving and calculating the above parameters is given in 4 of this part The definition of departments which may comprise several wards treatment rooms etc should be agreed at the project design stage to avoid confusion Safety The safety of MGPS is dependent on four basic tenets a identity b adequacy c continuity d quality of supply Version 2 0 June 2001 Page 18 of 264 Borders General Hospital NHS Trust on behalf of NHSScotland Property and Environment Forum 2 20 2 21 2 22 2 23 2 24 2 25 2 26 SHTM 2022 Part 1 Medical gas pipeline systems Identity is assured by the use of gas specific connections throughout the pipeline system including terminal units connectors etc and by the adherence to strict testing and commissioning procedures of the system Adequacy of supply depends on an accurate assessment of demands and the selection of plant appropriate to the clinica
247. s on an electricity supply the design should be such that failure of the electricity supply does not disrupt the flow of gas to the distribution system Version 2 0 June 2001 Page 51 of 264 Borders General Hospital NHS Trust on behalf of NHSScotland Property and Environment Forum SHTM 2022 Part 1 Medical gas pipeline systems Figure 1 Schematic layout of cylinder manifold 400 kPa system reproduced by kind permission of MED AES aml Dimension B System supply Dimension A Exhaust 5 J size cylinders 1520mm approx 5 5 Manifolds and control panels should be designed and certificated for use with 230 bar g cylinders The manifold headers should incorporate a Version 2 0 June 2001 Page 52 of 264 Borders General Hospital NHS Trust on behalf of NHSScotland Property and Environment Forum 5 6 3f 5 8 5 9 5 10 5 11 SHTM 2022 Part 1 Medical gas pipeline systems renewable non return valve to allow removal and replacement of any cylinder and to prevent the discharge of a bank of cylinders in the event of
248. s safety porterage storage and gfse The guidance given in this part should be fo all new installations and refurbishment or upgrading of existing staff safety would be compromise part should be followed esse tor compliance with this part A m should be prepared taking account of Scottish Hostal Planning Notes Design installation and testing This part of SHTM 2022 deals with the issues involved in the design installation and testing of an MGPS The standard specification Model Engineering Specification C11 supports this SHTM C11 provides details of the extent of the works required and is a procurement specification Whenever appropriate British Standard specifications should be used Version 2 0 June 2001 Page 15 of 264 Borders General Hospital NHS Trust on behalf of NHSScotland Property and Environment Forum 2 1 2 2 2 3 2 4 2 9 2 6 2 SHTM 2022 Part 1 Medical gas pipeline systems 2 General principles General statement An MGPS is designed to provide a safe and effective method of delivering the required medical gas from the source of supply through a pipeline system to the patient via a terminal unit Each medical gas must be supplied from a separate system and it is essential that all parts of each system are gas specific to ensure that there is no possibility of cross connection between any system A schematic diagram of a typical MGPS is shown in part 2 of
249. s than 200 l min of free air aspirated corrected to STP per kilowatt of electricity used when the pump is equilibrated at normal operating temperature and whilst maintaining pressure of 450 mm Hg 60 kPa The pump should be capable of producing Version 2 0 June 2001 Page 121 of 264 Borders General Hospital NHS Trust on behalf of NHSScotland Property and Environment Forum 9 17 9 18 9 19 9 20 9 21 9 22 9 23 9 24 SHTM 2022 Part 1 Medical gas pipeline systems a higher vacuum than that required in the pipeline so that the resistance of the bacteria filter and back pressure in the exhaust system can be overcome For this purpose the pump should be capable of providing a vacuum of not less than 650 mm Hg 87 kPa The capacity of the vacuum pump should be specified in terms of the free air aspirated FAA in l min when the pump is operating at a vacuum of 475 mm Hg 63 kPa and at 450 mm Hg 60 kPa at the plant pipeline connection The performance of any pump is a curve which varies between a negligible FAA at the maximum vacuum and maximum FAA at the atmospheric pressure so that the capacity of any pump depends on the vacuum at which it is operating If a single FAA capacity value is quoted for a vacuum pump it has no meaning unless it is referred to a single vacuum setting A pump should be chosen which has a good performance curve in the range 500 650mm Hg 67 87 kPa Vacuum pumps Vacuum
250. s the presence of low voltage 6 114 Each compressor should have a selector switch which when turned to the on position allows the maximum and minimu essure switches on the receiver to control the on and off loading of alternative auto position of the selector swith selection of the compressors NOTE The vacuum pump if providec orma t of the molecular sieve system Plant control indication 6 115 There should be indical rs for h compressor as follows b green com d for which indicates that the compressor motor is ele c anindi pressure produced by the compressor Compressor and vacuum starter units 6 116 There should be individual starter units for each compressor and vacuum pump which should include the features recommended for medical air compressor plants and vacuum plants respectively Molecular sieve control unit 6 117 The molecular sieve control unit may be mounted on the molecular sieve columns or may be located with the plant control unit There should be separate power supplies for the duty and standby sieve assemblies taken from the same phase Version 2 0 June 2001 Page 84 of 264 Borders General Hospital NHS Trust on behalf of NHSScotland Property and Environment Forum 6 118 6 119 SHTM 2022 Part 1 Medical gas pipeline systems The molecular sieve control unit should contain the following a9 5 p D a duty selector switch
251. services in local use The visual indicators should be arranged vertically in priority order with the normal indicators at the top The sequence of gas services should be from left to right a medical oxygen cryogenic and cylinders pressure swing adsorber PSA systems nitrous oxide nitrous oxide oxygen mixture medical air 400 kPa compressor plant eand synthetic air surgical air 700 kPa Oo GO Ss medical vacuum pumps nitric oxide z oxygen carbon dioxide mixture In addition to the gas seng indicators each panel must include a agreen power on ithout an audible signal b ared alarm dicator with an audible signal Labelling Panels sh lled as follows a medical Gas alarm b with the identification of the medical gas services indicated and the areas and departments served Construction The fascia panel should be removable to allow access to the rear of the fascia or to the panel for maintenance purposes Access to the interior of the panel should be tamper proof It should be possible to replace the source of illumination without removing the legend Panels should have electrical sections with protection at least equal to IP 32 of BS EN 60529 1992 Version 2 0 June 2001 Page 155 of 264 Borders General Hospital NHS Trust on behalf of NHSScotland Property and Environment Forum 12 45 12 46 12 47 12 48 12 49 12 50 12 51 SHTM 2022 Par
252. sh the water capacity of the cylinder of test gas medical air or nitrogen Fit the regulator onto the cylinder and read the pressure on the gauge Connect the pipeline pressure gauge to the pipeline and bleed the pipeline to zero gauge pressure Version 2 0 June 2001 Page 246 of 264 Borders General Hospital NHS Trust on behalf of NHSScotland Property and Environment Forum 10 11 12 SHTM 2022 Part 1 Medical gas pipeline systems Connect the cylinder to the pipeline and allow test gas to flow slowly into the pipeline up to pipeline distribution pressure Turn off the cylinder valve Allow the system to equilibrate for a few minutes Read the pipeline pressure gauge and the cylinder pressure gauge The volume of the pipeline may be calculated as follows cylinder volume x change incylinder pressure change in pipeline pressure Pipeline volume PV F PoVo5 P3V PiVo Vi P1 P3 Va Pa P2 Therefore where V cylinder volume Vo pipeline volume P initial cylinder gauge P3 final cylinder gaug Ps Initial pipeline The volume wate 23 3 litres be taken a of a G size medical air cylinder may be taken as water content of a J size medical air cylinder may To ensure maximum accuracy it is recommended that the system is vented and refilled 2 3 times and the average result taken Version 2 0 June 2001 Page 247 of 264 Borders General Hospital NHS Trust on beh
253. side wall Exits must be free of all obstructions Doors must open outwards All doors must normally be locked to prevent unauthorised access but should be provided with means of entry and exit in an emergency for example by a Version 2 0 June 2001 Page 176 of 264 Borders General Hospital NHS Trust on behalf of NHSScotland Property and Environment Forum 14 10 14 11 14 12 14 13 14 14 14 15 14 16 SHTM 2022 Part 1 Medical gas pipeline systems combination of a key in a break glass box and a push bar arrangement on the inside The internal walls including any internal doors of the manifold room should be suitable non combustible 2 hour fire resistant material as defined in BS 476 4 Internal doors should be avoided where practicable Heat detectors should be provided Construction and layout of manifold rooms The manifold room will contain the manifolds as well as cylinder racks holding sufficient spare cylinders to replace one bank of each manifold and the emergency reserve manifold Further replacement cylinders should be supplied from the non flammable medical gas cylinder store The size of the manifold room should therefore be determined from the size of the equipment as advised by the manufacturer Adeagate space should also be allowed for cylinder handling A typical automatic manifold with two duty m long and 0 6 m deep One extra cylinder o approximately 0 5 m to the overall le a
254. sion of MEDAES Vacuum Vacuum Vacuum Gauge Gauge Gauge Vacuum Vacuum Vacuum Receiver Receiver Receiver 2 3 V2 V4 V6 V14 gt lt gt lt gt lt gt lt V1 Bacterial Lea Filter Drain Trap Drain Drain x Drain Valve V1 Valve V3 Valve V5 vie x Distribution Pipe Connection V19 lt Flexible Flexible Test Point hose hose V1 5X V17 V8 V12 Bacterial d X X X Filter Drain Trap gt lt Exhaust V Exhaust xhaust V V13 Drain Trap Electrical Power Supplies for Each Vacuum Pump Motor Control o vit X Drain Trap Vacuum Sensor Pump 1 Pilot Central Control Motor Control OE Z H c5 O U JE J s Version 2 0 June 2001 Page 120 of 264 Borders General Hospital NHS Trust on behalf of NHSScotland Property and Environment Forum 9 11 9 12 9 13 9 14 9 15 9 16 SHTM 2022 Part 1 Medical gas pipeline systems Pump noise The noise level produced by the pumps will increase with the capacity of the Supply system For larger systems this can result in an unacceptable noise level at the pump The maximum free field noise level at 1 m from the u
255. specific requireme Where this resul the operationas will d pend on the method of primary supply ic number of cylinders being kept on site Should be set out giving details of procedures to be cylinder emeNyency reserve supply The operational policy should set out the action to be taken in the event of loss of the primary source of supply In the event of loss or failure of the primary source of supply the emergency reserve system should be able to provide at least for a short time the total system flow since it will not always be possible to advise users immediately of an emergency situation The operational policy should provide details of further action to be taken location of emergency manifolds cylinders etc Version 2 0 June 2001 Page 56 of 264 Borders General Hospital NHS Trust on behalf of NHSScotland Property and Environment Forum 5 31 5 32 5 33 5 34 5 35 5 36 5 37 5 38 SHTM 2022 Part 1 Medical gas pipeline systems Emergency reserve supplies for manifold installations The supply should be brought into operation automatically via a non return valve A two cylinder emergency reserve supply would normally be considered adequate for a cylinder manifold supply system The cylinder valve of one should be permanently open so that gas is immediately available The cylinder valve of the second cylinder should be closed so that by alternative use a continuous supply can be maintained A
256. stant terminal unit on each terminal unit to be tested Dep should decide the numbegand tested eously where appropriate able 24 b tests may be carrie out si ised c thetests ares Results Record th Its aForm B14 if they are in accordance with the specificati graphs 15 88 15 105 Tests for gaS identity General All systems should preferably be tested at the same time The previous tests must have been satisfactorily completed Procedure The tests specified in paragraphs 15 106 15 110 should be carried out at all terminal units using the equipment described in Appendix 6 Version 2 0 June 2001 Page 216 of 264 Borders General Hospital NHS Trust on behalf of NHSScotland Property and Environment Forum SHTM 2022 Part 1 Medical gas pipeline systems Results 15 205 Record the results on Form B15 if they are in accordance with paragraphs 15 106 15 110 and Table 25 System taken into use 15 206 When all the tests have been satisfactorily completed the construction labels should be removed and the system may be taken into use Version 2 0 June 2001 Page 217 of 264 Borders General Hospital NHS Trust on behalf of NHSScotland Property and Environment Forum SHTM 2022 Part 1 Medical gas pipeline systems Appendix 1 Testing commission and filling for use forms to be completed during testing and commissioning of piped medical gases systems Form Summary of test
257. such as a remote liquid facility separated from the hospital by roadways etc then it may be advisable to consider an additional emergency supply facility This may be either a apermanent manifold system located with the gnain hospital complex b a portable manifold system for example x izegcylinders mounted on a trolley for immediate use to be con w7non interchangeable screw thread NIST connectors fo Where such a permanent manifol s i lled this may fulfil the standby requirements if appropriately sized For a permanent manifol be fully automatic and protected by non ngements as indicated in the Cylinder manifold instalati tion of Chapter 5 5 stock control procedures Specific attention oiry dates on the batch label fitted to each cylinder The following indication of manifold conditions should be provided Indication Legend a green normal normal b yellow VIE low lt 25 re fill liquid c yellow VIE empty standby in re fill liquid immediately use d red pressure in standby system reserve low lt 50 e red pipeline pressure fault pressure fault Version2 0 June2001 ss ti itsi 3OW S Page 73 of 264 Borders General Hospital NHS Trust on behalf of NHSScotland Property and Environment Forum 6 59 6 60 6 61 6 62 6 63 6 64 6 65 SHTM 2022 Part 1 Medical gas pipeline systems Conditions b to e should be transmitted to the central
258. supplier The driver should fill the VIE without disturbing the customer s Supply pressure or flow and without lifting safety valves or blowing bursting discs After filling the driver should report any defects to the gas supplier immediately Version 2 0 June 2001 Page 71 of 264 Borders General Hospital NHS Trust on behalf of NHSScotland Property and Environment Forum SHTM 2022 Part 1 Medical gas pipeline systems NOTE All users should check their own installations and ensure that they are aware of the operating instructions The advice of the gas supplier should also be sought in cases of doubt Maintenance 6 40 Maintenance is the responsibility of the gas supplier but there are customer checks which should be carried out daily and weekly In addition it will be necessary to test the alarm system 6 41 To test the alarm system each alarm condition is initiated by the operation of a pressure switch The control panel is supplied with three way ball valves on the oxygen supply lines to each pressure switch Rotation of these valve handles through 180 allows oxygen pressure to the pressure switches to be reduced which operates the pressure switches and the appropriate alarms NOTE The high line pressure alarm requires secia st test equipment and marry ag this test Standby oxygen facility 6 42 A standby oxygen facility must al 6 43 lt should be sized to provide bulk liquid liquid cylinde 6 44
259. supplying the medical oxygen system or it may be from a dedicated VIE It would normally be more cost effective for the oxygen to be taken from the main VIE Version 2 0 June 2001 Page 103 of 264 Borders General Hospital NHS Trust on behalf of NHSScotland Property and Environment Forum SHTM 2022 Part 1 Medical gas pipeline systems although this would obviously depend on the existing VIE capacity the demand space constraints etc The feasibility study should provide more detailed information on whether it is likely to be more cost effective to provide a totally separate VIE system or to use the existing medical oxygen VIE Page 104 of 264 Version 2 0 June 2001 Borders General Hospital NHS Trust on behalf of NHSScotland Property and Environment Forum SHTM 2022 Part 1 Medical gas pipeline systems Figure 11 Typical synthetic air layout oxygen VIE supply reproduced by kind permission of BOC _ a X G L X M Se z SH ONAL ARRA MAIN VAPOR MAIN VAP BACK UP VAP
260. systems to monitor cylinder contents is recommended See also telemetry systems for VIE systems in the Bulk liquid oxygen section of Chapter 6 Liquid cylinder design Medical oxygen liquid cylinders are double walled with vacuum and multi layer insulation They are suitable for transportation and storage of liquid oxygen and provide a complete self contained gas supply system for hospital use Version 2 0 June 2001 Page 74 of 264 Borders General Hospital NHS Trust on behalf of NHSScotland Property and Environment Forum 6 66 6 67 6 68 6 69 SHTM 2022 Part 1 Medical gas pipeline systems Cylinders are designed and supplied with gas specific liquid fill and gas use connections as follows a Liquid fill CGA 440 b Gas use ISO 5145 Liquid cylinder manifolds In practice to cater for normal supply requirements liquid cylinders will be required to be manifolded together with the attendant control panel alarm and standby supply systems The manifold is designed to allow a number of liquid cylinders to be manifolded together in such a way as to complement their particular operating characteristics giving a single gas outlet point to the control panel Control panel The control panel is designed to maintain a required flow rate of up to 30 m hr 500 I min re re of 4 2 bar g at a Version 2 0 June 2001 Page 75 of 264 Borders General Hospital NHS Trust on behalf of NH
261. t 1 Medical gas pipeline systems Panels and their housings should be of adequate strength for their purposes and be manufactured from corrosion resistant materials lf gas services are brought into the panel they should be housed in separate enclosed compartments which are vented to the outside There should be gas tight seals where electrical services pass through any gas compartment Remote audible sounder All panels should have provision for connection to a remote audible sounder Central indicator panel requirements Displays The central panel should display all signals PSawhich are generated by the warning and alarm system Normal The normal condition for all piped green visual signal The norrgal alarm conditions ould be displayed as a steady ould extinguish in warning and r Warnings Warning conditig flashing yello audible signal s to each MGPS should be displayed as a al which may be accompanied by a mutable Emergenc Emergency avarms are generated by loss of pipeline pressure or vacuum and are indicated by flashing red visual signals accompanied by mutable audible signals Alarm system fault The alarm system fault condition should be displayed as a flashing red visual signal accompanied by a mutable audible signal Mute functions The temporary mute should cancel the audible signal for about 15 minutes and change the visual indicators from flashing to
262. t Forum SHTM 2022 Part 1 Medical gas pipeline systems Medical Gas Pipeline Total System Tests Form B4 Sheet Sheets Hospital Scheme File Number Date Leakage into Total Vacuum System Test This is to certify that a LEAKAGE test in accordance with paragraph 15 49 was carried out on the piped vacuum system at a system pressure of mmHg The pressure increase after 1 hour was mmHg max 10 mmHg Contractor s RepresenN Wiive Status Signed Date Name Contract Supervising Officer Status Signed Date Name Witnessed on behalf of Version2 0 June2001 lt OW lt lt lt Page 223 Of 264 Borders General Hospital NHS Trust on behalf of NHSScotland Property and Environment Forum SHTM 2022 Part 1 Medical gas pipeline systems Medical Gas Pipeline Total System Tests Form B5 Sheet of Sheets Hospital Scheme File Number Date Area Valve Service Units Closure and Zoning Tests This is to certify that CLOSURE and ZONING of the AVSUs was tested in accordance with paragraphs 15 50 15 57 on the pipeline system as follows AVSU Number Test Downstream Terminal Terminal Pressure pressure Units Unit kPa change after Controlled Labelling 15 min kPa Total no Contractor s Repreg Status Date Status Date Witnessed on behalf of By Status Signed Date Version 2 0 June 2001 Page 224 of 264 Borders General Hospital NHS Trust on behalf of NH
263. tant terminal unit on each branch must be tested with a membrane filter at a flow not less than 150 I min for 30 seconds The filter must be free from visible particles when viewed in good light A suitable test device is described in Appendix 4 All other terminal units should be purged Version 2 0 June 2001 Page 199 of 264 Borders General Hospital NHS Trust on behalf of NHSScotland Property and Environment Forum Test Particulates Pipeline odour Water Oil CO COs 15 97 15 98 SHTM 2022 Part 1 Medical gas pipeline systems Table 24 Summary for quality tests for medical gases pipeline systems Gas Paragraph Specification Test result All 15 95 Practically free Practically free from from visible visible particles on particles in 75 membrane filter sample Oxygen and 15 105 None No odour medical air and Surgical air All 15 99 115 VPM 0 095 H2O detection tube mg l equivalent to satisfactory dewpoint 40 C at atmospheric pressure Medical air 15 97 Oil 400 kPa detection Surgical air tube 700 kPa satisfactory oxygen supplied from PSA plant Medical air 15 101 Gas 400 kPa detection Surgical air tube 700 kPa satisfactory Oxygen supplied from PSA plant Medical air lt 500 ppm v v Gas 400 kPa detection Surgical air tube satisfactory lt 300 ppm v v it of resolution of human eye ay be used instead of H2O detector tubes e is required to detect these
264. this SHTM Operational management Figure 1 systems for dental air and vacuum are cove 1 Dental compressed air and vacuum syste different However where anaesthetic departments the guidance given in thi M2022 Supplement requirements are istered in dental During the installation stage exten there is no cross connection Where medical air 400 medical equipment thi MGPS should n used to supply pathology departments general ical services The 400 kPa medical air system may surgical tool are serviced such as in sterile disinfection units SDUs electronic ant biomedical equipment EBME workshops etc In such cases only to facilitate the testing and checking of operation of equipment for the different medical gases all terminal units excluding vacuum may be connected to the medical air supply and be provided with simplified alarm facilities and labelled accordingly Separate installations should be provided for pathology and general laboratories and workshops although it is recommended that they are constructed to the same specification as MGPS They should not be provided with medical gas terminal units Piped medical vacuum systems are not recommended for infectious disease units Version 2 0 June 2001 Page 16 of 264 Borders General Hospital NHS Trust on behalf of NHSScotland Property and Environment Forum 2 8 2 9 2 10 2 12 SHTM 2022 Part 1 Medical gas pipeline systems Q
265. this case the guidance given in this SHTM should be followed ce with this SHTM A epand taking account of e with medical colleagues and take account of other ublished by the Department of Health in order to assess the syste al shortcomings Existing installations should be assessed for plan for upgrading the existing system shoult b This part of Scottish Health T chni randum SHTM 2022 looks at ISSUES of design installation nd validation It covers the user on the design installati ovimodation of plant and medical pipeline distribution systems In Vddition this part describes the procedures to be r 2 pipeline system MGPS can be taken into iad out at each stage of the installation programme This part is nded for use by designers installers manufacturers operational managers engineers quality controllers technicians finance officers and other professionals involved in the day to day running of an MGPS The primary objective of this part is to ensure the provision of safe and reliable MGPS and their efficient operation and use This objective will only be achieved if the medical and nursing users and estates staff participate in the introduction of an operational policy designed to minimise the hazards likely to arise from misuse of the system Version 2 0 June 2001 Page 2 of 264 Borders General Hospital NHS Trust on behalf of NHSScotland Property and Environment Forum SHTM 2022 Part 1 M
266. though this will be for a short duration Sources of pollution and pr n oMAGS systems 10 18 sources of pollution inci ade the ing a excess gas fr ry valve on the breathing system discharge the driving g iratory port of the ventilator which may include spillage frm receiving system of the AGSS 29 a2 9 diffusion through tubing this is thought to be negligible g discharge from gas monitoring equipment when used 10 19 An AGSS can remove only pollution which can be captured at source that is it can only remove pollution from the first two and the last sources It cannot remove pollution from any other source Local ventilation systems may remove pollution discharged into the environment although the effectiveness of such systems is being investigated 10 20 In practice this means that an AGSS can only be used to remove pollution from anaesthetic breathing systems incorporating an expiratory valve or port which complies with the requirements of BS EN 737 and BS EN 740 to which an AGSS can be connected Version 2 0 June 2001 Page 131 of 264 Borders General Hospital NHS Trust on behalf of NHSScotland Property and Environment Forum 10 21 10 22 10 23 10 24 10 25 10 26 10 27 10 28 10 29 SHTM 2022 Part 1 Medical gas pipeline systems Therefore AGSS should only be installed in areas where anaesthetic gases are administered as a general anaesthetic via a breathing syst
267. ting sy em e housed in separate units or may be installed ina anel and located on the plant or on the plantroom wall ion All functions should be have a design life of at least one The control Wait should have a separate power supply for each pump controlled by separate sub circuit It should be manufactured and installed in accordance with IEE regulations and the design should be such that no single component failure in the control unit will result in loss of plant output The unit should allow either manual selection of duty standby for each of the pumps or have an automatic sequence selection with a means for manual override The control unit should ensure that two or more pumps do not start simultaneously when power is applied A warning notice which complies with BS 5378 Part 3 1982 should be affixed which indicates the presence of low voltage For testing purposes each pump should have a selector switch which when turned to the on position allows the pump to run continuously Version 2 0 June 2001 Page 125 of 264 Borders General Hospital NHS Trust on behalf of NHSScotland Property and Environment Forum 9 53 9 54 9 55 SHTM 2022 Part 1 Medical gas pipeline systems Plant control indication There should be indicators for each compressor as follows a green mains supply on green pump operating which indicates that the pump motor is electrically energised b green pump
268. tings c when brazing ensure adequate protection of adjacent pipe runs to avoid oxidation Pipe preparation Pipe ends should be cut square with the pipe axis using sharp wheel cutters and cleaned of any cuttings or loose burrs Expanded joints should be made using the appropriate tools and dies Only where the cut pipe has either deformation or a burr which significantly restricts flow of gas will de burring be necessary Use of No internal inert gas shield Application the inside of the pre assembled egulator and flow controller or flow Oxygen free nitrogen should be su unbrazed pipework through regulating device lf necessary the purge yas shold be fed from two ends of a T joint Care should also be tak sto Wasure iat other pipelines in close proximity to the one being braze Foto due to heat transfer Pair This may be followed during the brazing operating termittent flow as necessary to prevent the ingress of may be capped if desired to direct the flow of N2 into sections ipes to be brazed Particular attention should be given to the gas shielding of T joint fittings Safety lf working for prolonged periods in very confined spaces precautions must be taken to avoid excessive build up of nitrogen by ventilating the space or by piping the shield gas safely out of the space NOTE If necessary the oxygen content of the ambient air should be monitored Version 2 0 June 2001 Page 165 of 264
269. ts connected to the plant should be fitted with flexible connectors where necessary to prevent the transmission of noise and vibration along the pipelines and Q Version 2 0 June 2001 Page 179 of 264 Borders General Hospital NHS Trust on behalf of NHSScotland Property and Environment Forum 15 1 15 2 15 3 15 4 15 5 15 6 15 7 SHTM 2022 Part 1 Medical gas pipeline systems 15 Validation and verification General This section covers the validation and verification and filling for use of MGPS The requirements for anaesthetic scavenging systems are also covered in paragraphs 15 118 15 139 The test procedures and methods are also included in this chapter The objective of testing and commissioning is to ensure that all the necessary safety and performance requirements of the MGPS will be met Testing and commissioning procedures will be reqgired for new installations additions to existing installations and modificatig is togxisting installations The scope of work will dictate the specific test required This is This chapter describes the tests require test methods Tests are listed in Appendix 1 and the assoc For extensions comprising fewer th brazed joints all the tests may be sure test being replaced by a leak test An extension com deemed to be a small i uiring all the appropriate tests to be carried out up to the fin tion and leak test For the purpose of S a straight
270. ts open and in use Ideally this would mean inserting a test device into every terminal unit on the system and checking at each terminal unit in turn that the required criteria are met In practice it is sufficient to connect a receiving system conforming to BS EN 737 and BS EN 740 to every terminal unit and to then check each terminal unit in turn The contractor should provide a certificate giving details of the performance of the system Receiving system The induced flow into the receiving system by th tested at every receiving system to ensure th exceed 0 5 I min isposal system should be duced flow does not The procedure and the test equipment gquiretyare described in BS EN 737 and BS EN 740 Performance efficiency ce is set out in BS EN 737 and BS EN comprising a mixture of oxygen and It should not be receiving detect any nitrous oxide in the vicinity of the n the system is challenged in this way This test is ult To carry out under site conditions since it is not easy to set up the covxect challenge flow and the ambient conditions will affect the results This t st should be carried out under laboratory conditions by the manufacturer of the receiving system and a certificate should be provided in accordance with BS EN 737 and BS EN 740 lt may be necessary to carry out an assessment of the performance of an existing scavenging system which does not comply with BS EN 737 and BS EN 740 In this case t
271. ts should be of a type Suitable for mounting within the specified fitting Pressure losses across terminal units should be in accordance with BS 5682 1998 The standard does not give pressure loss data for surgical air at 350 l min but see Table 4 Version 2 0 June 2001 Page 26 of 264 Borders General Hospital NHS Trust on behalf of NHSScotland Property and Environment Forum SHTM 2022 Part 1 Medical gas pipeline systems Table 2 Scale of provision of terminal units Department O2 N20 N20 O2 MA4 SA7 VAC AGSS Accident and emergency department Resuscitation room per trolley space 1 1 1 1 1 Major treatment room plaster room per trolley space 1 1 1p 1 1p 1 1 Post anaesthesia recovery per trolley space 1 1p 1 Treatment room cubicle 1 1 Operating department Anaesthesia room 1 1 1 1 1 Operating theatre Anaesthetist 1 1 1 1p 2 1 Surgeon 1 1 1 1p 2 1 Post anaesthesia recovery per bed space Equipment service room per work space Maternity department Delivery suite Normal delivery room Mother Baby Abnormal delivery room Mother Baby Operating suite ef work space Neonatal unit per cot space 2 2 2 i ent service room per work space 1 1 1 provision for 2 cots only irrespective of number of cot spaces Where the delivery suite and Neonatal unit are in close proximity one equipment service room can be shared In patient accommodation
272. typical system is shown in Figure 2 Emergency reserve supply for air compressors liquid oxygen oxygen concentrators PSA The supply should normally comprise a two bank manifold system A typical number of cylinders in each bank would be five ix depending on size and location See also the Chapter on bulk liquid pply systems for more details of the back up and emergency Quppwetacili Location th The emergency reserve manifold in the manifold rooms of the primar other systems should similarly ge 3 linder system should be located Reserve manifold rooms for in an appropriate manifold room Design Except as stated conform to the cy reserve manifold systems should en manifold supply systems in general Provision showld also be made for an emergency reserve inlet supply for either a replacement or alternative supply Emergency reserve supplies for liquid oxygen systems are covered in the Bulk liquid oxygen systems section of Chapter 6 It may be advisable to locate the emergency reserve supply or the emergency supply facility where provided in a location remote from the primary source of supply Version 2 0 June 2001 Page 57 of 264 Borders General Hospital NHS Trust on behalf of NHSScotland Property and Environment Forum SHTM 2022 Part 1 Medical gas pipeline systems Figure 2 Emergency supply manifiold reproduced by kind permission of MED ES Supply from Distribution main pane
273. uality requirements for medical gases and air Medical gases supplied from cylinder or liquid sources comply with the appropriate sections of the current edition of the European Pharmacopoeia Ph Eur There is currently no Ph Eur for site generated medical air and oxygen pressure swing adsorber PSA systems The quality specification for medical air is as given in Table 1 The introduction of the new Ph Eur for medical air was effective from 1998 and therefore medical air will need to comply with this new specification The Ph Eur also specifies validation protocols which will need to be adopted The quality of piped medical compressed air the particulate content dryness and concentration of impurities should comply with the requirements for maximum concentrations given ingl able 1 which is based on the specification for breathing air in BS EN 142 1991 Information on testing procedures is given in Chapter 15 V and verification Table 1 Quality specification for medical for the requirement for dental compre supplement ir efer to the relevant Parameter I Specification Oxygen xs 0 9 1 0 Nitrogen 78 by inference Practically free from visible particles in a 75l sample Particulate contamination 115 vpm 0 095 mg l equivalent to dewpoint 40 C at atmospheric pressure Water content CO 5ppm v v COz 500 ppm v v Oil content drof set or mist lt 0 5 mg m Odour see paragraph 2 11 non
274. uce the number of cylinders on site It is essential that any relaxation of the number of cylinders held should be Version 2 0 June 2001 Page 59 of 264 Borders General Hospital NHS Trust on behalf of NHSScotland Property and Environment Forum 6 7 6 8 6 9 6 10 6 11 SHTM 2022 Part 1 Medical gas pipeline systems validated and documented with the gas supplier clearly stating responsibilities and expectations for supply of cylinders Where additional outlet points are installed on a pipeline system fed from a VIE the hospital should notify the gas supplier to ensure that changes in consumption do not jeopardise the security of stock With the use of telemetry systems it is possible to monitor gas usage and thus optimise the delivery frequency whilst maintaining adequate stocks The gas supplier should advise on the most appropriate vessel size for a particular site geographic location and the standby requirements taking into account the demand peak consumption and site location Equipment description The system is designed to provide a liquid oxygen VIE at a pressure of at le b standby oxygen facility with a capacity o supply to protect against VIE supply failu c stand alone emergency supply f against failure from the VIE tobe Standby oxygen facility This may be provided b a standby liquid b manifold li c manifold co ssed gas cylinders System la The various Sxstems ar
275. uid petroleum gas ambient air torches Additional heating may be required for some fittings for example by means of a second torch Version 2 0 June 2001 Page 163 of 264 Borders General Hospital NHS Trust on behalf of NHSScotland Property and Environment Forum 13 23 13 24 13 25 13 26 13 27 13 28 SHTM 2022 Part 1 Medical gas pipeline systems In order to maintain the pipeline cleanliness and prevent formation of verdigris after completion it will be necessary to maintain the completed system charged with medical air until the installation is finally commissioned On larger projects completed sections of pipeline should be similarly protected The techniques recommended cover all copper to copper joints and all copper to brass gunmetal bronze joints in an MGPS and are explained in more detail below By agreement between the health facility management and the pipeline contractor the use of a purge gas may be waived on joints such as break ins to old pipeline systems where pipe joints will not have been made in accordance with this new technique This new technique should be used on all medical gas pipeline services The method is recommended for use in other non cli epartments in hospitals such as pathology laboratories Jointing methods Mechanical threaded or flanged joi connected to items such as valves trol equipment For vacuum pipelines of 76 mm diameter and ab wed or flanged compress
276. uld not give greater than 1 respt resence of 100 nitrous oxide 100 nitrogen or 100 carb 5 Nitrous oxide and nitric oxide could be present at up to 100 co NOTE A paramagnetic meter is the specified instrument for identity of oxygen ontrations if the system has been inadequately purged Nitrous oxide The nitrous oxide sensor should not give greater than 1 response in the presence of 100 oxygen 100 nitrogen or 100 carbon dioxide An infra red fuel cell meter is now commercially available Specification The equipment should be portable preferably battery powered with digital or analogue indication of 0 100 to one decimal place The battery should give at least eight hours continuous running between recharging or replacement Version 2 0 June 2001 Page 243 of 264 Borders General Hospital NHS Trust on behalf of NHSScotland Property and Environment Forum SHTM 2022 Part 1 Medical gas pipeline systems An accuracy better than 1 is required with a zero stability of 2 5 per day The response time must be not more than 15 seconds to 90 of the final reading Procedure This ts as follows a Calibrate the equipment to check zero and 100 response b regulate the flow of gas from the terminal unit to the equipment c allow the reading to stabilise d record the result for each terminal unit Version 2 0 June 2001 Page 244 of 264 Borders General Hospital NHS Trust on beha
277. um 0 22 5 23 5 24 5 25 5 26 5 2 7 5 28 5 29 5 30 SHTM 2022 Part 1 Medical gas pipeline systems The panel can be incorporated into the manifold control unit or be a separate unit within the plantroom If mounted separately the cabling should be monitored for open short circuit In the event of such a cable fault a red system fault lamp should be illuminated on the alarm signal status unit together with the appropriate alarm condition Emergency reserve supply General A permanently connected reserve supply system must be provided for all MGPS including nitric oxide systems excluding 700 kPa surgical air systems for emergency use or to permit servicing or repair The reserve supply should be designed when practicable to provide the same flow rate as the primary system and have sufficient connected Capacity to supply the pipeline for at least 4 hous When such provision would result in six cylinders or more on each additional cylinders should be held in the manifold rooms A non and isolating valve should be installed immediately upstream of t e manifold connection to the pipeline distribution system The requirements for the emergen out in the operational policy agd sh situation for cylinders liquid s system flow that would resvxve supply capacity should be set ak into account the local supply in th event of an emergency and the The gas supplier should be consulted The
278. um 4 82 4 83 SHTM 2022 Part 1 Medical gas pipeline systems Table 13 Vacuum design and diversified flow Department Design flow for each Diversified flow Q l min terminal unit l min In patient acute Ward units single and multi bedrooms 40 QW 40 40 Treatment rooms 40 QT 40 nB 1 rs Departments ward areas 40 QD 80 nB 1 1 Operating department Operating room 40 QT 80 Anaesthetic room 40 Operating suite 0 2 S 2 120 1 operating room 40 n 40 Recovery room 40 QR 40 nB 1 40 ITU and CCU QI 40 nB 1 Pi Intensive ther ry care unit and neonatal unit Each terminal un assumed minimum ould be capable of passing 40 l min but it may be o Of bed spaces will require vacuum simultaneously All other highlependency areas should be treated as ITU CCU Version 2 0 June 2001 Page 50 of 264 Borders General Hospital NHS Trust on behalf of NHSScotland Property and Environment Forum 5 1 5 2 5 3 5 4 SHTM 2022 Part 1 Medical gas pipeline systems 5 System design general Cylinder manifold installation General Manifolds should be connected to the pipeline via a control panel which provides two equal banks of gas cylinders The changeover from the duty to the standby bank of cylinders should be automatic All manifolds should be capable of passing the full pipeline flow The temperature of the gas may fall as lo
279. upply units as appropriate There is a third stage which applies to vacuum systems only The whole installation is tested with the vacuum plant in operation Purging and testing must be carried out with clean oil free dry air or nitrogen except for those tests where medical air or the specific working gas is prescribed All test gases must meet the particulate contamination requirements of paragraph 15 95 The shield gas may be used for the leakage test on the pipeline carcass described in paragraph 15 39 Medical air from the compressor plant may be used to test medical air and vacuum systems provided the quality tests including those for particulate contamination as discussed in paragraphs 15 88 15 105 have been carried out Cylinders must always be used as the source of test gas for oxygen nitrous oxide oxygen carbon dioxide and oxygen nitrous oxide Version 2 0 June 2001 Page 185 of 264 Borders General Hospital NHS Trust on behalf of NHSScotland Property and Environment Forum 15 21 15 22 15 23 15 24 15 25 15 26 15 27 15 28 SHTM 2022 Part 1 Medical gas pipeline systems systems in order to prevent the possibility of contamination with oil Argon should be used for testing nitric oxide systems Before the pipeline system tests are carried out every terminal unit in a system under test must be labelled to indicate that the system is under test and that it should not be used NOTE The terminal
280. us unit 8 20 Compressor supply system 8 21 Plant status monitoring 8 22 Plant indicator unit design surgical air 700 kPa page 112 Version 2 0 June 2001 Page 7 of 264 Borders General Hospital NHS Trust on behalf of NHSScotland Property and Environment Forum SHTM 2022 Part 1 Medical gas pipeline systems 8 25 Alarm signal status unit 8 30 Plant management 8 31 Operating considerations 8 32 Simplex plant 9 System design medical vacuum supplies page 118 9 1 Medical vacuum supplies 9 1 General 9 9 Siting 9 11 Pump noise 9 13 Vacuum plant exhaust 9 16 Efficiency 9 18 Vacuum pumps 9 35 Pressure control 9 37 Valves 9 39 Pressure regulation of vacu 9 42 Vacuum indicators 9 44 Electrical supply 9 45 Pump operating and 9 45 9 49 9 53 9 54 9 99 lant st jus monitoring t us indicator unit Alarm signal status unit 9 62 10 Sy ign anaesthetic gas scavenging systems page 129 10 1 AnaeSthetic gas scavenging systems 10 1 General 10 10 Background 10 18 Sources of pollution and provision of AGS systems 10 32 AGS system design 10 32 General 10 35 Active and passive systems 10 40 General design requirements 10 46 Safety criteria 10 48 Performance criteria 10 51 Flow diversity 10 52 Discharge outlet Version 2 0 June 2001 Page 8 of 264 Borders General Hospital NHS Trust on behalf of NHSScotland Property and Environment Forum 11 11 1 12 12 1 12 7 12 10 12 11 TaT Version 2 0
281. use of nitric oxide as a selective pulmonary vasodilator has had a major impact on the management of both neonates and adults suffering from respiratory distress syndrome The immediate impyevement in the patient s condition with nitric oxide has made its use routs ough the long term benefits have yet to be established by clinic inders located at the ver adds to the congestion n additional safety hazard to AV size cylinder is more acerwates the likelihood of running out vasoconstriction resulting in hypoxia either AV 10 litre or AK 40 litre al bedside The introduction of such in highly serviced ward spaces an both staff and patients Wher manageable its smaller c which could cause pati and pulmonary hyperte ribution system is intended to provide a safe delivery It also helps to reduce congestion in the Design con derations In the UK nitric oxide for medicinal use is currently supplied as a mixture of 1000 ppm in nitrogen This may change in the future The therapeutic concentration of nitric oxide required in the patient breathing system is normally between 5 and 20 ppm with a maximum flow at each terminal unit of about 200 ml min The gas is administered in conjunction with medical oxygen to maintain the appropriate oxygen concentration to the patient NOTE The breathing system should include nitric oxide and nitrogen dioxide monitoring systems In the presence of oxygen nitric oxide forms higher ox
282. ut ig7BS EN and BS EN 740 should be followed Where the AGSS issins d wi included in the nn Performance tesv 1g other medical gases systems it should be n tests as specified in paragraph 15 58 The dispos should be tested to ensure that it meets the following requirements lt regardless of the number of terminal units on the system Pressure drop Extraction flow 1 kPa maximum 130 l min 4kPa minimum 80 l min NOTE Developments in oxygen standards may result in reduced extract flows for systems in the future These criteria should be met regardless of the number of receiving systems connected to the disposal system The test should be carried out as described in BS EN 737 and BS EN 740 Where a disposal system is designed to operate with more than one terminal unit that is more than one receiving system in use simultaneously Version 2 0 June 2001 Page 205 of 264 Borders General Hospital NHS Trust on behalf of NHSScotland Property and Environment Forum 15 130 15 131 15 132 15 133 15 134 15 135 15 136 15 137 15 138 15 139 SHTM 2022 Part 1 Medical gas pipeline systems the test should demonstrate that the above criteria can be met under all conditions that is with one or all of the terminal units in use The test device should therefore first be inserted into each terminal unit in turn with all other terminal units closed The test should be repeated with all other terminal uni
283. ve in the event of failure of duty sieve low O2 concentration dryness or pressure iv check the operation and calibration of sensors for O2 concentration dryness and pressure and all pressure gauges and thermometers v check the operation of all pressure regulating valves and non return valves vi check the activation of appropriate fault indicator and associated volt free contacts and that the sub assembly remains in this mode of operation until the fault has been rectified vil check the operation of each dryer sub assembly function indicator vill check operation in the event of a power failure to ensure that all valves close in a fail safe mode and to ensure the operation of the emergency manifold ix carry out the same checks for each c res or as for compressed air plant x check the operation of all plant at its Maxi continuous rating and check that the design spec ionior flow pressure and quality is achieved xi check the operation of the ingaand alarm system and the plant indicator unit Pressure safety valve Check that the sp valves have bee essy safety valves line valves and non return Verify thatthe va specificati are certified to operate in accordance with the contract orm to BS 6759 Part 2 1984 Warning syy tems The operation of warning systems should be tested in all operating and emergency conditions for one function at a time and one system at a time Particular att
284. via multiplexed cable for example using pulse width modulation see Figure 18 The transmitter may be a separate unit or may be incorporated i in plant or manifold control panel ii in a separate unit iii in an indicator panel Cases ii and iii should include line fault monitagng devices b indicator panels which display the trans c interconnecting multiplex wiring which congect ransmitters to all indicator panels System layout Central system igure 16 which shows initiating devices at remote locations suc as the acuum insulated evaporator VIE m plantrooms nitrous oxide manifold room g devices Indicator panels are typically located oange the porters room and the engineer s office to provide in equiring action by engineering and other support staff Certain criti are areas such as theatres delivery suites special care baby units ar intensive care units should also have repeater indicator panels on the Central system to show emergency alarms which require action from the user Area warning and alarm systems A typical layout of an area system is shown in Figure 17 For each gas service there should be local pressure switches for high and low pressure These conditions should be indicated on a locally mounted indicator panel with facility to provide a common alarm condition for connection to other alarm panels The extent of the interconnecting wiring in an area alarm system is reduced
285. w as 30 C as the gas passes through the regulator at maximum Capacity and the equipment should be designed accordingly A schematic layout for a typical installation is giv is usually provided on the basis of one week s manifold should hold not less than two days u days should be held in cylinders in the store in Figure 1 Total storage The nominal and usable capacity of the Cy aedeis commonly used on manifolds are given in Table 14 tke figyres are ne equivalents at standard temperature and pressure Table 14 Capacities of medi al as Cylinders used on manifolds Gas Nomina apacity litres at Usable capacity litres 137 Wr g Oxygen J size 6a 0 6 540 Nitrous oxide Js 18 000 G si 9 000 8 900 Nitrous oxi 5 000 4 740 mixtures G si Medical air J s 6 400 6 220 5 550 Oxygen carbon dioxide 6 800 6 540 mixture 5 COs J size Nitric oxide AU size 1 500 Nitric oxide AK size 4 000 This may be subject to change The usable figures are for discharges down to a gauge pressure of 7 bar g Two sets of figures are provided for air for 400 kPa systems and 700 kPa systems the latter is for discharge down to 15 bar g An automatic manifold changeover from duty to standby should occur at a cylinder pressure which will ensure the greatest possible utilisation of the contents of the cylinders in the duty bank If the normal operation of the changeover control depend
286. which should then be tested to ascertain its performance The responsibility for the tests should be clearly identified at the contract stage for new installations in the same way as for the MGPS In general the contractor should carry out the tests which should be witnessed by the Version 2 0 June 2001 Page 204 of 264 Borders General Hospital NHS Trust on behalf of NHSScotland Property and Environment Forum 15 122 15 123 15 124 15 125 15 126 15 127 15 128 15 129 SHTM 2022 Part 1 Medical gas pipeline systems authorised person MGP S It is unlikely that each health authority or trust can justify the purchase of the specialist equipment required to carry out these tests unless there are a significant number of AGSS installed on the site The general requirements set out in this volume for validation and verification should be followed including tests for cross connection and mechanical function of terminal units Performance tests disposal systems Powered device All equipment should be tested to ensure that it performs satisfactorily during continuous operation under full load for one hour All electrically powered equipment should be tes zd as follows check for correct rotation b check the current through the powered device load th c check the insulation resistance iveness of the earthing of all electrical items Pipework ductwork install n The procedure set o
287. with extraneous metal work for example where the pipes are carried in metal partitions or where terminal units are mounted on metal bed head units the pipelines should be effectively bonded to the metal work in accordance with Regulations 525 10 of the IEE Regulations Where piped gases and electric wiring are enclosed in a boom gas control panel or other similar enclosure the wiring should be carried in separate conduit or trunking so that it cannot come into direct contact with the piped gas installation Where this is not possible the wiring should be secured in the most effective manner possible clear of the medical gas pipes The cables should comply with IEE Regulation 523 17 Electrical wiring in plantrooms All electrical wiring in these rooms should be carri cable of the type indicated in IEE Regulation 52 protection against mechanical damage out using MICS cable or ith adequate Fire resistant cable conforming to BS 6387 FYC red cables and single insulated cables in conduit ma be ised Each compressor vacuum pump separate sub circuit ifold should be supplied from a Metal clad sockets conn ts and switches should be used in uld provide segregation of low voltage functional extra low voltage LV electrical services by means of flexible partitions or conduit as appropriate Access to live components should be via panels which are removable by means of tools only Version 2 0 Jun
288. y one or more of the NIST connectors while the cover is locked The AVSU may include provision for pressure gauges pressure switches by means of separate bosses Version 2 0 June 2001 Page 172 of 264 Borders General Hospital NHS Trust on behalf of NHSScotland Property and Environment Forum 13 73 13 74 13 75 13 76 13 77 SHTM 2022 Part 1 Medical gas pipeline systems The enclosure should have adequate ventilation to prevent the accumulation of gas in the event of a leak Pipe entries and other penetrations should be sealed to prevent gas escape by routes other than the vents or openings into the user space The enclosure should be designed to facilitate sealing of these entries on site AVSUs should be clearly labelled to indicate their function and the areas beds etc served Emergency access should not compromise the labelling Provision of AVSUs General AVSUs should be provided as follows for general wards one valve near the entragcve to the ward b for intensive therapy units recovery sp valve at the entrance plus additional val between four and eight beds The latter s control more than c for operating departments o at the entrance to the department plus valves to control each suite operating room recovery room anaesthetic room and if plaster room d all other departmen e for vacuum service AVSUs Phould be provided to facilitate maintenance rtments as day care sur
289. y should not be liable to drop out due to shrinkage or subsequent movement of the pipe or timber Such precautions are not required where untreated timber is used or where the treated timber is effectively sealed with paint or varnish before the pipes are fixed to it Version 2 0 June 2001 Page 168 of 264 Borders General Hospital NHS Trust on behalf of NHSScotland Property and Environment Forum 13 52 13 53 13 54 13 55 13 56 SHTM 2022 Part 1 Medical gas pipeline systems Identification of pipelines Pipelines should be identified in accordance with BS 1710 and colour banding for the pipelines should be used outside of the plantroom Colour band identification see Figure 19 should be applied near to valves junctions walls etc Each gas should be identified in 6 mm letters Self adhesive plastic labels of approved manufacture may be used for this purpose A band 150 mm wide is usually adequate All colour coded tapes applied by the pipe manufacturers should be removed before the systems are identified in accordance with this paragraph Care should be taken to maintain pipeline identification when periodical re painting is undertaken The direction of flow should be indicated Pipeline fittings General Pipeline fittings which may be attached to a in terminal unit valves area valve service units components such as emergency inle e various types of Zand other V rpose type The
290. ype Oil free compressors may be beneficial in reducing filtration requirements Where water is used as the sealant it should be de mineralised and the compressor should be provided with suitable feed water pre treatment Such treatment must ensure that there is no risk of microbial contamination to the air supply In the event of failure of the water treatment system the compressor should automatically shut down to ent contamination There is a danger that PTFE rings and lubri high temperatures to form toxic products Thi temperature sensor to the cylinder he suitable controls to cut off the power temperatures are sensed decompose at ountered by fitting a e compressor with compressors if excessive On start up when oil is used pressure forms an emulsi Where oil from conde sompressors are used suitable means of separating oil e should be provided Once a compressor installation has been selected a the number required should be left to the supplier of the plant The plant should include at least two compressors but additional compressors may be included provided that in all cases the total capacity will provide 100 of system design flow with one compressor not running b the individual compressors should be arranged so that they will supply the system simultaneously if necessary c the relative magnitude of the capital and running costs should be evaluated at the time of purchase Too much emphasis has be

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