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BOTSWANA STANDARD BOTSWANA BUREAU OF

1. cccccccceeeeeseeececeeeeeseeeanaeceeeeeeedeeaaeaeceeeeeeeseaaeaeeeeeeeeaseqaeaeeeeeseeeeeesanaeess 27 9 2 Low pressure extinguishers ssessssssssssssssssssseseeeeenen nenne seen en nnne nemini insi ninh SEEE tiir s nn nnne nens nas 27 9 3 Carrying Bare SE AE 31 9 4 MOUNU MEER 31 9 5 Caps valves and cloSureS cied secte oret Parece e 31 9 6 Safely devic8s uper tete bete e rtr uic oat oce rte cie or dee is ic eub reme 32 9 7 Manufacturing tests 2a te bleed ee P Tee i reete 32 9 8 Requirements for plastics components esses eene ener ener enne nnns 32 9 9 Hose assemblles 2 itte ERE ERRAT EROR 34 910 Method of operation ut eee tee 35 9 11 Safety locking deviGes aceite o t ette d e dr 35 9 12 Requirements for pressure gauges and indicators for low pressure extinguishers 36 9 13 Dip tubes and filters water based extinguishers sssssseeeeene enne nens 38 9 14 Special requirements for CO extinguishers sssssssssssssssseseeen eene nnne nennen 38 9 15 Gasketand o riligs ide nega eed ette a cl 39 10 Marking and Colour cot et chs rn Pe t wens PR RE e 39 39 39 10 3 Inspection i erem 41 11 Manuals sieves x 41 11 1 Us
2. SNOILONHLSNI 38 WIYLSNONI 804 9v1 NOS3LYO 30uYH23H QNY 39NYN31NIVW 040934 04023H 385 930 AQ08 3 NO 034 15 sew TINA 64251 39 00 394234 A131v03AMI 39 33 35 ANY H313V ISN SUYAS AV3A3 SINN3YINOJY 2 100 01 183134 CILVASOWOAH 980 801 NYOH 03 2 S1uYd 039 ANY 30 1434 f P A 03323 5501 SSYN dI 300238 3308300 SI M3HSITONLLX3 JUNSNI OL SHINON 21 AUJA 43 9 3 3 32NYNLNINIM Nid ONIN T1Nd O3LONYLSBONN SI NHOH SUNS IMN 15 I 1139 ONY 30 139 8 2 SI USHSINONILX3 n 1VH1 493H2 ATHINOW 193dSNI NOILO3dSNI 1H9IHdf QOH 3 3 3uld FOIXOIO NOBHYD By Figure 5 Example of layout marking for an extinguisher 42 BOS 252 2007 B Key 1 Class A Ordinary solid material fires 4 Class D Combustible metal fires 2 Class B Flammable liquid fires 5 Fire involving energized electrical conductors 3 Class C Gas and vapour fires 6 Class F Combustible cooking media fires Figure 6 Use code symbols 43 BOS 252 2007 Key 1 Pan diameter 2 Nominal wall thickness 2 3 Skirt to suit burner type 4 Burner Figure 7 General Dimensions for Class F Test Apparatus Type A Apparatus for Class SF Only Key 1 Topedge 2 Tray to support gas burners alternatively electric heating may be used 3 Skirt
3. 8 5 5 4 General The fire consists of melted metal poured into the steel tray described in 8 5 4 1 positioned on a level surface with an obstruction formed from a 50 mm 5 mm length of steel I beam 100 mm deep and 100 mm wide positioned centrally in the tray on its side in the attitude of an arch as shown in Figure 3 24 BOS 252 2007 Dimensions in millimetres Key 1 Obstruction 2 Testpan 3 Molten fuel Figure 3 Obstructed magnesium spill fire configuration 8 5 5 2 Fuel Use 11 3 kg 0 1 kg of the magnesium alloy described in 8 5 2 2 8 5 5 3 Procedure Heat the magnesium alloy in the covered melting pan described in 8 5 4 1 until completely melted Carefully remove the cover and continue to heat until the temperature reaches 650 C 10 C above the melting point if the fuel does not ignite spontaneously use the gas torch see 8 5 2 1 to ignite it Pour the fuel into the tray but not directly over the obstruction As soon as the burning fuel has spread across the tray the fire can be attacked at the operator s discretion using the manufacturer s recommended extinguishing techniques After discharge is completed follow the procedure described in 8 5 2 3 8 6 Electrical conductivity of extinguisher discharge 8 6 1 Water based extinguishers Water based extinguishers that are marked as suitable for use on energized electrical equipment fires shall 25 BOS 252 2007 not pass a cu
4. bottom front or either side but not the back of the crib at will Maintain all devices for controlling the flow of the extinguishing media in the position for maximum discharge to ensure a continuous jet 8 4 Class B test fire 8 4 1 Location Carry out test fires up to and including 144B indoors Carry out test fires larger than 144B indoors or outdoors but with the wind speed not exceeding 3 m s Do not carry out tests outdoors when rain snow or hail is falling BOS 252 2007 ed DX bd Dd PX Dd DI Dd D x i Key 1 Ignition pan 2 Support frame 3 Weighing platform Figure 2 Crib fire Table 8 Wood crib ignition arrangement Class A rating Ignition pan size Heptane charge mm 1A 400 x 400 x 100 1 1 2A 635 x 635 x 100 2 0 3A 700 x 700 x 100 2 8 4A 825 x 825 x 100 3 4 6A 1 000 x 1 000 x 100 4 8 10A 1 090 x 1 090 x 100 7 0 15A 535 x 535 x 100 7 6 20A 1 170 x 1 170 x 100 8 2 a See 8 4 3 6 4 2 Construction Class B test fires utilize a range of welded sheet steel cylindrical trays dimensions given in Table 9 The sides are vertical The base of the trays are set horizontal and level with the surrounding ground NOTE Reinforcement of the base of the larger test fire trays will be necessary to minimize distortion In such cases it 20 BOS 252 2007 will be necessary to ensure that the underside of the trays are not exposed to the a
5. control valve shut so as to keep the extinguisher under pressure Conduct the impact test as follows Mount a steel cylindrical hammer of 75 mm diameter and total mass of 4 0 kg with flat faces vertically in loose guides so that it can drop freely through a height minimum height 300 mm given by h andhz0 3 20 h isthe height expressed in metres m isthe total mass of extinguisher expressed in kilograms The extinguisher shall be placed on a rigid flat surface in each of the following two positions in turn a in the normal upright position with the longitudinal axis of the hammer coincident with the longitudinal axis of the BOS 252 2007 valve b lying on its side so that the valve rests on a rigidly fixed steel block In each of the above positions submit the valve of the extinguisher to an impact by allowing the steel hammer to fall vertically onto it from the height h The point of impact is to be determined by the authority carrying out the test 7 5 2 Resistance to vibrations 7 5 2 1 Test principle An extinguisher shall be capable of withstanding exposure to the conditions of a vibration test without development of physical weakness which would impair its normal operation 7 5 2 2 Extinguisher mounting requirements Extinguishers supplied with a wall hook or bracket not intended for use in vehicles shall be subjected to the test specified in 7 5 2 5 2 Extinguishers supplied with a bracket for use in vehicles s
6. 1270 33 layers of 17 pieces of wood NOTE f necessary in the future it is intended that this table be extended to include larger test fires These will be constructed on the same principles as those now listed Each Class A rating is designated by a number in a series which is proportional to the mass of wood contained in a crib i e a 20A crib contains twice the mass of wood as in a 10A crib All cribs are cubic with the volume of the open space approximately equal to the volume of the wood 8 3 3 Procedure Place an ignition pan of appropriate size as specified in Table 8 on the floor under the crib Level the pan as far as is possible and then add sufficient water to cover the base Pour the appropriate volume of fuel as specified in Table 8 into the pan Ignite the fuel Remove the pan once the liquid has been consumed Allow the crib to burn until its mass is reduced to 55 2 96 of its original mass The mass loss may be determined directly or by other methods which can be demonstrated to provide equivalent correlation NOTE This will take 6 min to 10 min Either monitor the mass continuously or determine the time by a preliminary test or tests extinguishing the fire s and measuring the mass and core diameters making adjustments as necessary Apply the discharge of the extinguisher to the test fire initially to the front and from a distance of not less than 1 8 m Reduce the distance of attack and apply the discharge to the top
7. 16 clean agent electronically non conductive gaseous or vaporizing liquid fire extinguishant that does not leave a residue upon evaporation 3 17 lowest observable adverse effect level LOAEL lowest concentration at which an adverse physiological or toxicological effect has been observed 3 18 wet chemical wet chemicals include but are not limited to aqueous solutions of potassium acetate potassium carbonate potassium citrate or combinations of these materials 4 Classification of extinguishers Extinguishers shall be classified by the type of extinguishing medium that they contain At present the main classes of extinguishers are as follows a water based b powder c carbon dioxide and d clean agents BOS 252 2007 These classes of extinguishers may be further sub divided for example water based extinguishers may contain pure water or water with additives such as wetting agents viscosity increasing agents flame retardant foaming agents or wet chemical etc 5 Extinguishing media propellants and filling requirements 5 1 Extinguishing media 5 1 1 Carbon dioxide Carbon dioxide used in extinguishers shall comply with BOS ISO 5923 5 1 2 Clean agents Clean agents used in extinguishers shall comply with the appropriate part of ISO 14520 NOTE In some countries the manufacture and use of clean agents is regulated by the Montreal Protocol or by national regulations 5 1 3 Powders Powders used in extinguishers sh
8. 3 To verify the attachment of plastic parts following the air oven ageing ultraviolet light exposure and impact resistance tests attach the plastic part s to an extinguisher and then subject the assembly to the appropriate pressure test 9 8 2 Requirements for normally pressurized components 9 8 2 1 Burst strength 9 8 2 1 1 Conduct burst tests at three temperatures as described below 9 8 2 1 2 Subject at least three components to the burst test in accordance with 9 2 2 using an appropriate liquid at temperatures of 20 C 3 C the minimum recommended operation temperature marked on the extinguisher see 7 1 and 55 C 3 C Increase the pressure at a rate of 2 0 MPa min 0 2 MPa min 20 bar min 2 bar min 9 8 2 1 3 The bursting pressure before and after the ageing and ultraviolet light exposure test shall be at least equal to the minimum burst pressure Pp 9 8 2 2 Air oven ageing 9 8 2 2 1 Subject at least three components to accelerated ageing in an oven at 100 C 3 C for 180 days Fit the components with adapters to apply normal assembly stresses 9 8 2 2 2 Following the exposure condition the components for 5 h at 20 3 C and subsequently inspect them for cracking No cracking shall be permitted 9 8 2 2 3 Subject the components to the burst test in accordance with 9 2 2 at 20 3 C using a suitable liquid at a rate of pressure increase of 2 0 MPa min 0 2 MPa min 20 bar min 2 bar min The bursting pre
9. deformation test the test pressure shall be increased by 10 NOTE An acceptable test apparatus is the water jacket test as defined in CGA Compressed Gas Association pamphlet C 1 section 1 0 Other methods are also acceptable 9 2 5 Pressure cycling test A minimum of two cylinders shall be tested An extinguisher cylinder shall sustain without rupture 5 000 cycles from 0 to the test pressure P and back to 0 at the rate of 6 cycles min At the conclusion of testing the cylinder shall be subjected to and comply with the burst test 9 2 6 Welded low carbon steel cylinder 9 2 6 1 The cylinder material shall be capable of being welded and shall contain a maximum of 0 25 96 carbon 0 05 of sulfur and 0 05 of phosphorous 9 2 6 2 Filler material shall be compatible with the steel to give welds with properties equivalent to those specified for the base sheet 9 2 6 3 The cylinder shall have a measured thickness greater than the minimum thickness given by the 29 BOS 252 2007 following formula but in no case less than 0 70 mm where S is the minimum thickness expressed in millimetres D is the outside diameter of the cylinder or for non cylindrical bodies the greatest external diagonal of the extinguisher body expressed in millimetres k is the coefficient equal to 0 45 for Ds 80 0 50 for 80 lt D lt 100 0 70 for D 100 9 2 7 Stainless steel cylinders 9 2 7 1 Stainless steel domes and bottoms shall
10. medium There shall be no damage to polymeric siphon tubes which have been conditioned in accordance with 9 8 6 3 when installed in test extinguishers and subjected to the mechanical resistance test described in 7 5 Following conditioning in accordance with 9 8 6 3 ring samples cut from polymeric siphon tubes shall not exhibit degradation in excess of 40 of the original tensile or ring crushing strength value Place complete siphon tubes in contact with the media with which they are to be used Totally cover or immerse ring samples 12 7 mm wide cut from unaged siphon tubes in the media Ensure the samples do not touch each other or the container holding the media and samples Place the container of media with the samples in place in a preheated oven at 90 C 3 C for 210 days After the test exposure cool the samples in air at 23 C 2 C for at least 24 h before any tests or dimensional measurements are conducted Subject the ring samples to a crush test between two parallel flat plates using a testing machine capable of applying a compressive load at a uniform rate of 5 mm min and recording the load versus the deflection If the nature of the material is such that meaningful test results cannot be obtained other tests such as tensile tests may be conducted 9 9 Hose assemblies 9 9 1 Extinguishers with a charge greater than 3 kg or 3 litres shall be equipped with a hose assembly having a minimum length of 400 mm 9 9 2 The hose
11. melt during the firefighting process and may include a safety helmet with heat resistant face guard visor a long coat or overalls and gloves of aluminized insulated cloth 8 2 2 Requirements for extinguishment Test fires shall be regarded as extinguished if a For Class A all flames are extinguished There shall be no flames visible 10 min after complete discharge of the extinguisher The appearance of non persistent flames during the 10 min period shall be ignored Non persistent flames are defined as less than 50 mm in height and less than 1 min duration If the Class A crib collapses during the test it shall be considered void and a fresh test carried out b For Class B all flames are extinguished and there remains a minimum heptane depth of 5 mm at any point in the tray For Class all flames are completely extinguished There shall be no re ignition of the vegetable oil for 20 minutes after discharge or until the temperature decreases to at least 35 C below the auto ignition temperature whichever is longer 8 2 3 Test extinguishers and method of use Use extinguishers filled and charged according to the manufacturer s instructions Store the extinguishers for no less than 24 h at a temperature of 20 C 5 C and maintain this temperature until tested Use the extinguishers according to the manufacturer s operating instructions It is permitted at the operator s discretion to operate a gas cartridge extinguisher
12. so as to allow the operating pressure to increase in the body prior to discharge 6 2 4 Test schedule Test schedule the basic schedule of testing is a set of three fires A Class A Class B or Class F rating is achieved by extinguishing two out of three fires of the same size Class D suitability for a particular metal or form of metal is established by extinguishing either the first fire of the set or if this is not extinguished extinguishing the second and third test fires A set comprises fires consecutively carried out and the result of any particular test fire is not to be disregarded Each set is to be completed before another is started For Class A Class B and Class F fires a set is completed either when all three test fires are carried out or when the first two test fires are both BOS 252 2007 successful or both unsuccessful For Class D fires a set is complete when the first test is successful or when the first and second fires are both unsuccessful or when all three are carried out Water based models which may be produced with or without an antifreeze agent shall be treated as separate and distinct models for the fire rating test 8 3 Class A test fire 8 3 1 Location Conduct the tests in an essentially draught free room having adequate volume and ventilation to ensure the necessary supply of oxygen and reasonable visibility for the period of the test Air inlet openings at or near ground level as given in Table 6 wi
13. subject to national pressure vessel regulations 5 3 2 Filling tolerance The actual charge of an extinguisher shall be the nominal charge within the following limits BOS 252 2007 a water based extinguisher lt by volume b powder extinguishers 1 kg nominal charge 5 96 by mass 2 kg but 3 kg nominal charge 3 96 by mass 3 2 kg nominal charge 2 96 by mass NP 596 clean agent extinguishers 5 by mass Bee 296 d carbon dioxide extinguishers 5 by mass 5 3 3 Charges The following are the recommended charges for fire extinguishers a water based I 2 3 6 9 b powder kg 1 2 3 4 6 9 12 C C02 kg 2 5 d clean agent kg 1 2 4 6 6 Pressure requirements for low pressure extinguishers 6 1 Test pressure Pt The test pressure Pi for low pressure extinguishers shall be 1 43 x Pms but in no case less than 2 MPa 20 bar 6 2 Minimum burst pressure Pb The minimum burst pressure for low pressure extinguishers is 2 7 x Pms but in no case less than 5 5 MPa 55 bar 7 General operating performance requirements 7 1 Operating temperatures Extinguishers shall be capable of operating reliably within one of the following temperature ranges a 5 C to 55 C b 0 to 55 C C 10 C to 55 C d 20 C to 55 C e 30 C to 55 C f 40 C to 55 C i 1 bar 100 kPa 0 1 MPa 1 Pa 1 N m2 BOS 252 2007 9 55
14. the operable pressure range of the extinguisher The zero service and maximum indicated gauge pressures shall be shown in numerals and with marks The background of the gauge face above a horizontal line through the lowest required markings shall be red The arc of the dial from the zero pressure point to the lower end of the operable range shall read Recharge The arc of the dial from the higher end of the operable range to the maximum indicated pressure shall read Overcharged All numerals letters and characters in the recharge operable and overcharge portions of the dial shall be white Pointers shall be yellow and the tip of the pointer shall end in the arc of the pressure indicating dots and shall have a maximum tip radius of 0 25 mm The length of the pointer from the point of rotation of the pointer to the tip measured at the zero pressure point shall be at least 9 mm for extinguishers having a charge greater than 2 kg or at least 6 mm for extinguishers having a charge of 2 kg or less The length of the arc from zero pressure to the indicated service pressure shall be at least 12 mm for extinguishers having a charge greater than 2 kg or at least 9 mm for extinguishers filled with clean agents or having a charge of 2 kg or less 9 12 1 5 The mark used to indicate the service pressure at 20 C should be no less than 0 6 mm and no more than 1 0 mm wide 9 12 1 6 The pressure gauge face shall be marked to indicate the appropriate extin
15. the requirements of 9 3 2 and 9 3 3 9 3 2 A handle shall be no less than 90 mm long for an extinguisher of 7 0 kg or more total mass and no less than 75 mm long for an extinguisher of less than 7 0 kg total mass 9 3 3 There shall be no less than 25 mm clearance between extinguisher body and the carrying handle when the handle is in the carrying position 9 4 Mounting 9 4 1 Each extinguisher intended for wall mounting shall be provided with a means of mounting Carry out the testing on one extinguisher bracket only of each model or type supplied with the extinguisher 9 4 A wall mounting hook shall require both a horizontal and a minimum 6 mm vertical motion to remove the extinguisher from the wall EXCEPTION A minimum vertical motion of 3 mm is acceptable for an extinguisher having a gross mass of 5 4 kg or less 9 4 8 A mounting bracket shall be capable of withstanding a static load of five times the fully charged mass of the extinguisher but no less than 45 kg when tested in accordance with 9 4 4 9 4 4 Place an extinguisher charged to its rated capacity in the mounting bracket provided with the extinguisher after the mounting bracket has been secured to a wood board Secure the board in a vertical position and apply a static load of four times the full extinguisher mass or a total load of 45 kg minus the full extinguisher mass minimum to the top of the extinguisher Hold the load for 5 min 9 4 5 A mounting bracket equipped wi
16. to 13 mm wide and 0 05 mm thick The reagent grade magnesium shall contain no less than 99 5 96 magnesium and the nominal particle size shall be 6 mm to 9 mm long 3 mm wide and 0 25 mm thick For the tests without cutting oil use 18 0 kg 0 1 kg of metal for each fire For the tests with cutting oil use 16 2 kg 0 1 kg metal evenly coated with 1 8 kg 0 1 kg of a petroleum base cutting oil of relative density 0 86 0 01 having a Cleveland open cup flashpoint value of 146 C 5 C for each fire 8 5 2 3 Procedure For each test prepare the fuel bed in the removable metal or wood frame Level the surface of the fuel using a rake or straight edged board Remove the frame Apply the igniting torch to the centre of the fuel bed removing the torch after 25 s to 30 s Allow the fire to spread until it is estimated that either 25 of the fuel is burning or the fire covers 50 of the fuel bed surface whichever occurs sooner The extinguisher may then be discharged onto the fire at the operator s discretion continuously or intermittently according to the manufacturer s instructions Check that fuel is not scattered off the base plate during the attack After discharge is completed allow the fire bed to remain undisturbed for the period of time recommended by the extinguisher manufacturer or if no time is recommended for 60 min Examine the fuel bed and check that the fire is completely extinguished and that more than 10 of the origi
17. 0 bar whichever is greater 9 2 2 6 Furthermore the break shall not occur in any body permanent marking such as stamping or engraving 9 2 2 7 During the burst test no parts shall be ejected from the extinguisher 9 2 2 8 The burst test shall not cause the valve and fitting to fragment The break shall not originate in the valve or fitting marking area 9 2 3 Crushing test Crush a minimum of three extinguishers perpendicularly to their longitudinal axis and at their midpoint using two 25 mm thick mandrels with a radius at their apex of 12 5 mm and a width sufficient to extend beyond the sides of the extinguisher see Figure 4 Crush the cylinder over a period between 30 s and 60 s In the case of extinguishers with a longitudinal weld place the weld seam at 90 to the support lines For extinguishers with central transverse welds apply the mandrel at 45 to the weld seam After the crushing test fill the extinguishers with water and increase the pressure to test pressure P The extinguishers shall not exhibit any cracks or leaks 28 BOS 252 2007 R 12 5 mm where Dr is the distance after test D isthe outside diameter of cylinder Figure 4 Crushing test 9 2 4 Permanent volumetric expansion test There shall be no permanent expansion in excess of 10 of the total expansion of the cylinder when subjected to the test pressure P for 30 s For cylinders that have been proof pressure tested prior to the
18. 8 96 for clean agent extinguisher gauges At the zero pressure mark the error shall not exceed 12 96 nor fall below 0 96 of the service pressure Ps At the maximum indicated pressure the error shall not exceed 15 96 of the service pressure Ps 9 12 2 3 The pressure gauge or indicator is to be installed on a deadweight gauge tester or a piping apparatus with a master gauge having an accuracy of no less than 0 25 96 The pressurizing medium may be oil water nitrogen or air but all tests on a given type of gauge are to be conducted using the same medium The pressure is to be applied to the gauge under test in uniform increments until the upper limit of the gauge is reached The pressure then is to be reduced in the same increments until the zero point is reached The pressure applied the gauge or indicator reading and net error are to be recorded for each increment in both the increasing and decreasing pressure conditions 9 12 3 Burst strength test gauges and indicators 9 12 3 1 A pressure gauge or an indicator shall withstand for 1 min a pressure of six times the indicated Service pressure without rupture In addition if the Bourdon tube or pressure retaining assembly bursts at a pressure less than eight times the indicated service pressure no parts of the device shall be discarded 9 12 3 2 Attach the sample gauge or indicator to a hydraulic pressure pump after all air has been excluded from the test system Place the sample in a te
19. B or Class AB powder extinguishers only 8 1 4 Class D Extinguishers recommended as suitable for Class D fires shall extinguish the appropriate test fire or fires when tested as described in 8 5 NOTE Extinguishers suitable for Class D fires are usually not suitable for use on fires of other classes Specialized media and applicators are typically used BOS 252 2007 8 1 5 Class F Extinguishers recommended as suitable for class F fires shall extinguish the appropriate test fires as described in 8 7 and pass the splash test requirements as described in 8 8 In addition wet chemical type extinguishers shall meet the requirements of section 8 6 8 2 Test fires General 8 2 1 Operator s clothing To carry out these tests the operator shall wear suitable working clothing NOTE 1 Attention is drawn to the necessity for taking precautions to safeguard the health and safety of personnel conducting the tests against the risk of fire and inhalation of smoke and any toxic products of combustion and compliance with any national legislation which may apply concerning the health and safety of the extinguisher operator and other personnel NOTE 2 Respiratory protection may be worn to protect the operator from effects of the repeated testing over a period of time Such protection is not intended to permit an otherwise intolerable exposure to any fumes and or smoke from a single fire NOTE 3 Suitable working clothing should not be liable to ignite or
20. BOTSWANA STANDARD BOS 252 2007 Fire fighting Portable fire extinguishers Perfomance and construction BOS 252 2007 BOTSWANA BUREAU OF STANDARDS BOS 252 2007 Contents Page Foreword mU cnr E M RU n E ii 1 Som M X 1 2 Normative references RR e e re e e be ds 1 3 Terms and definitions ege eere ete c i deese tete ce 1 3 1 Classification ol TIF8S i i e uf ied epos diea EU e TE UT EXE Lee ee 1 4 Classification of extinguishers sess nennen nnne sn terret renis n nenne nenas 2 5 Extinguishing media propellants and filling requirements em 3 5 1 Extinguishing media a tdi eret dt DE deo d ened ata 3 5 2 Propellants reddit inaurata adii 3 5 3 Filling redg lreimients di act tin eee o a etin 3 6 Pressure requirements for low pressure extinguishers 0 0 00 cece eeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeseeeeeeseeeaeeeeeeeaeees 4 6 1 Test pressure Pt ecce iae cantet eu i Pope petu 4 6 2 Minimum burst pressure Pb asssieeessiieeeseseeeeeeseeenne eese PR CAAA REA AE nnns tenens entr n sene teneis n tenen nn nnns 4 7 General operating performance requirements ssssssssssssseeee eene nnne 4 7 1 Operating temperat fes a creer or oie etii do cet nt etes de it i p ata Ds 4 7 2 Minimum effective dis
21. C C 24 t 1 Store at minimum stated Store at 55 C 2 C temperature 2 C 24 t 1 Store at 20 C 5 C Store at 20 C 5 C 24 t 1 Store at 55 C 2 C Store at minimum stated temperature 2 C NOTE The storage temperatures refer to the ambient temperature within the conditioning chamber Do not use a liquid bath a See 7 1 Operate the extinguisher within 2 min after its removal from the conditioning chamber The extinguisher shall be held in its normal working position and shall remain immobile for the duration of the test The extinguisher shall be operated in accordance with 7 2 2 2 Measure and record the time between the opening of the final control valve and the commencement of discharge Reweigh the extinguisher and calculate and record the residual charge BOS 252 2007 7 4 Retention of charge 7 4 4 Routine checks 7 4 1 1 Extinguishers shall be designed so as to permit their charge to be checked at regular intervals when they are installed 7 4 1 2 The charge of the following shall be measured by weighing a carbon dioxide extinguishers b stored pressure extinguishers of various types including some clean agents in which a mass loss of 1 96 of total mass is accompanied by a pressure loss of not more than 10 of the service pressure at 20 C 2 7 4 1 3 The charge of stored pressure extinguishers of types not covered in 7 4 1 2 b and c shall be checked by direct measurement of inte
22. C to 55 C The temperature range selected from the above ranges shall be marked on the fire extinguisher see 10 2 1 5 For water based extinguishers without any protection against freezing the minimum operating temperature shall be 5 7 2 Minimum effective discharge time and bulk range of discharge 7 2 41 Class A rated extinguishers rating 7 2 1 1 Effective discharge The minimum effective discharge time of extinguishers with a 1 A rating shall be no less than 8 s Extinguishers with ratings of 2 A or higher shall have a minimum discharge time of 13 s 7 2 1 2 Requirements When three portable fire extinguishers are tested following 7 2 1 3 the duration of operation of each extinguisher shall be within 3 s of the average value for powder extinguishers and within 15 of the average value for other extinguishers but the duration value shall not be less than the minimum specified 7 2 1 3 Test method Testing of portable extinguishers shall be carried out within 2 min of removal of the extinguisher from the conditioning temperature Portable fire extinguishers for testing shall be stored in a vertical position for at least 18 h at a temperature of 20 C 5 C before the tests are carried out and shall be maintained within this temperature range until tested Weigh the extinguisher Hold the extinguisher in its normal working position Left hand held and keep it immobile for the duration of the test For extinguishers which a
23. Record the bulk range of the extinguisher as the range at the time corresponding to 50 96 of the effective discharge time NOTE Where the range of effective discharge is difficult to determine visually supplementary means such as collection boxes for powders and condensing plates for liquefied gases may also be used 7 3 Resistance to temperature changes 7 9 4 Requirements Portable extinguishers shall be able to operate at temperatures within one of the temperature ranges given in 7 1 as indicated by the manufacturer and comply with the following requirements after being subjected to the conditions given in 7 3 2 a shall operate as intended b commence discharge within 5 s of the opening the control valve 0 not retain more than 10 of initial charge within the extinguisher following complete discharge 7 3 2 Test method Carry out testing on four extinguishers Before testing weigh each extinguisher then subject two extinguishers to temperature cycle 1 as given in Table 2 and subject the other two extinguishers to temperature cycle 2 as given in Table 2 Storage at the temperatures given in Table 2 shall be carried out in conditioning chambers liquid baths shall not be used and the extinguishers shall remain upright during temperature cycling The tolerances given in Table 2 shall be considered as nominal tolerances with the climatic chamber empty Table 2 Temperature cycles Duration Cycle 1 Cycle 2 h
24. Subject the extinguisher to the variable frequency and amplitude specified below in each orientation specified in 7 5 2 5 1 Frequency Hz Amplitude mm 10 to 19 0 75 0 08 20 to 39 0 50 0 05 40 to 60 0 25 0 03 Vibrate the extinguisher for 5 min at each frequency and increase the frequency at discrete intervals of 2 Hz b Vibrate the extinguisher for 2 h at the frequency which produced the maximum resonance as determined in a above or if no resonance is observed subjected to the test specified in 7 5 2 5 2 7 6 Resistance to corrosion 7 6 1 External corrosion test Subject complete and fully charged extinguishers including their mounting bracket and wall hook to a salt spray test as defined in ISO 9227 type NSS only NSS Neutral Salt Spray Test for a period of 480 h Following a drying period of at least 24 h at room temperature carefully wash the extinguisher to remove any salt deposits Test two samples i e either two of the same size or one sample each of two different sizes from the same family At the conclusion of the test the following requirements shall be satisfied a the mechanical operation of all working parts shall be unimpaired the force required to release the safety device shall be as specified in 9 11 1 b the minimum effective discharge time and method of operation shall comply with requirements specified in 7 2 and 9 10 the pressure gauge if one is fitted shall remain functional and waterti
25. all comply with BOS ISO 7202 EXCEPTION Powders for use on Class D fires 5 1 4 Foam concentrates Foam concentrates used in extinguishers shall comply with the appropriate part of BOS ISO 7203 NOTE There is no ISO Standard covering non foaming additives sometimes added to water to produce antifreeze wetting or other special characteristics However such extinguishers are included in the category of water base extinguishers Water based agents When the extinguishing agent has a pH exceeding 9 5 a warning statement shall be required for the extinguisher nameplate see paragraph 10 2 1 1 5 2 Propellants The propellants for stored pressure and cartridge operated extinguishers shall be air argon carbon dioxide helium or nitrogen or mixtures of these gases having a maximum dew point of 55 C EXCEPTION Propellant for stored pressure water based extinguishers need not meet the above dew point Tracers may be added to the propellant to facilitate leakage detection but the content shall not exceed a mass fraction of 3 96 of the propellant content Tracer percentage shall be indicated by the manufacturer and verified by the test laboratory 5 3 Filling requirements 5 3 1 Fill density The maximum fill density for carbon dioxide extinguishers shall not exceed 0 75 kg t The fill density for clean agent fire extinguishers shall not exceed the values given in the appropriate part of ISO 14520 NOTE 1 The above fill densities may be
26. and coupling system shall function throughout the operating temperature range and coupling systems shall be designed and fitted in such a way that they cannot damage the hose 9 9 3 The burst pressure of a hose assembly fitted with a shut off nozzle shall be equal to or greater than the appropriate value below The test pressure shall be established by increasing the pressure to the minimum allowable burst pressure in a time no less than 30 s maintaining that pressure for 30 s during which failure shall not occur and then increasing the pressure until failure 9 9 4 For all types except CO and clean agent extinguishers a 2 0 times the maximum service pressure Pms the test being carried out at 20 C 5 C b 1 5 times the maximum service pressure Pms the test being carried out at 55 C 2 9 9 6 For CO2 and clean agent extinguishers a 1 5 times the maximum service pressure Pms the test being carried out at 20 C 5 C 34 BOS 252 2007 b 1 25 times the maximum service pressure Pms the test being carried out at 55 C 2 C 9 9 7 Where testing is to be carried out at 55 C 2 C condition the hose and attached components at the relevant temperature for a period of not less than 12 h 9 9 8 The hose shall be fitted to a means of providing the required pressure and the open end blanked off by suitable means The hydraulic test fluid shall not cause the hose assembly to decrease in temperature 9 9 9 Rec
27. anism and shall require a force of no less than 20 N but not exceeding 100 N It shall be possible to determine whether the apparatus may have been operated 9 11 2 The safety device shall be so constructed that any unaided manual attempt using a force or impact equal to twice the relevant value given in Table 10 to initiate discharge without first operating this device does not deform or break any part of the mechanism in such a way as to prevent the subsequent discharge of the extinguisher 9 11 3 The safety locking device shall be made of a corrosion resistant material 9 11 4 The safety locking pin or other device shall be visible from the front of the extinguisher when the extinguisher is mounted in its mounting bracket EXCEPTION The safety locking pin may be on the reverse side of the extinguisher if pictographic operating instructions on the front illustrate the intended method of operation 9 11 5 If the safety locking device is attached to the extinguisher by a chain or similar device the chain shall be attached so as to not interfere with the discharge stream 35 BOS 252 2007 9 11 6 A tamper indicator such as a seal shall be provided to retain the safety locking device in place and to indicate tampering with or use of the extinguisher 9 11 7 The tamper indicator shall be constructed so that it must be broken to operate the extinguisher The force required to break the tamper indicator shall not exceed 70 N EXCEPTION If
28. ay be added to the word INSTRUCTIONS b the operating instructions shall be in the form of numerically sequenced pictographs A single pictograph may include two instructions the sequence of pictographs shall illustrate with pictures the recommended actions necessary for intended operation of the extinguisher Words may be added The sequence shall be as follows 1 making ready the extinguisher by disengaging the safety locking device 2 aiming the extinguisher at the base of the fire including the recommended distance from the fire at which to begin discharge and indicating the intended operating attitude of the extinguisher 3 taking whatever action necessary to initiate operation of the extinguisher 4 describing the intended method of applying the extinguishing media on the fire 10 2 2 5 The height of the words when used in the pictographs shall be least 3 0 mm high 40 BOS 252 2007 10 2 3 Use code symbols 10 2 3 1 Use code symbols see Figure 6 shall be positioned directly below the operating instructions A written description for each use code symbol may be included as part of the code in letters having a minimum height of 1 0 mm 10 2 3 2 The use code symbols shall have dimensions no less than 16 mm x 16 mm and no more than 32 mm x 32 mm excluding the borders 10 2 3 3 Use code symbols shall be placed on the extinguisher for those types of fires for which the extinguisher is classified For those classes of
29. be drawn from fully annealed stock 9 2 7 2 Only austenitic stainless steel having a maximum carbon content of 0 03 96 shall be used NOTE An example of such steel is AISI type 304L 9 2 7 3 The cylinder shall have a minimum measured wall thickness greater than the minimum wall thickness given by the following formula but in no case less than 0 64 mm sa L ek 600 where S is the minimum wall thickness expressed in millimetres D is the outside diameter of the cylinder or for non cylindrical bodies the greatest external diagonal of the extinguisher body expressed in millimetres k is equal to 0 3 9 2 8 Aluminium cylinders 9 8 3 1 Aluminium cylinders shall be of a seamless construction 9 8 3 2 Aluminium cylinders shall have a measured wall thickness greater than or equal to the minimum thickness given by the following formula but in no case less than 0 71 mm SP ok 300 Where S is the minimum thickness expressed in millimetres D is the outside diameter of the cylinder or for non cylindrical bodies the greatest external diagonal of the extinguisher body expressed in millimetres 30 BOS 252 2007 K is the coefficient equal to 0 2 for D lt 100 mm 0 3 for D gt 100 mm 9 3 Carrying handle 9 3 1 An extinguisher having a total mass of 1 5 kg or more and having a cylinder diameter of 75 mm or more shall have a carrying handle NOTE The valve assembly head itself may be considered a handle provided it meets
30. ce of the extinguisher and particularly that of the head and fittings to damage from falling objects or from impact with fixed surfaces 7 5 1 1 Requirements The extinguisher shall not release pressure in a potentially dangerous manner when tested in accordance with 7 5 1 2 The portable extinguishers shall be judged fit and proper if during the course of the impact tests there is no evidence of bursting breakage or ejection of components which would put the safety of the user at risk 7 5 1 2 Test method The test shall be carried out on two charged portable fire extinguishers One extinguisher shall be tested horizontally and the other vertically Condition the extinguishers correctly charged and equipped with all the fittings which are subject to internal pressure in normal operation for 18 h to the minimum working temperature 2 C see 7 1 Within 2 min after the removal of the extinguisher from the conditioning chamber it shall be subjected to the impact test described below For the purpose of this test an antifreeze agent may be added to prevent freezing of the contents of water based extinguishers Carbon dioxide extinguishers shall be filled to 95 of volume with water or water plus antifreeze agent and pressurized with nitrogen to the working pressure they would reach at the test temperature if charged with CO If the extinguisher is of the gas cartridge type fit the charged cartridge and activate the extinguisher with the
31. charge time and bulk range of discharge sse 5 7 3 Resistance to temperature changes eessseseeeseseeenee ee R TEA NEERA ANAE enses nnne enne nnne 7 7 4 Retention OF Charge cic 3c wake er etre ated rae dre tiet ca etd eser bandas 8 7 5 Mechanical resistance ete rc e trece ER 9 7 6 ReSISTANGE TO COMOSIONs reete ert exte od de ar ct ete epe 11 7 7 Tappirig test sooo ete ite tee t ce ie e tet rer eer ocr 12 7 8 Intermittent discharge testes pete et tee fede td edite ri eta eee Rente 13 8 Performance requirements for test fires 0 0 2 cece eeeeceeeeeeeceeeeeeeeeeeeeaeeeeeesaeceeeeeeeeeeeseeeeeeneeaeseeseeeeeeenenees 15 8 1 Rating suitability for the various classes of fire sssssssssseeeeenm ene 15 8 2 Testitos Gerleral eta a 17 8 3 Class A Test TITO eee imr Ee rire ie o rhe UY ERE der RR REY PER Te 18 8 4 Class BITES HE ronen E Podere IE i Dr Y EE Oda EE ERE a NER EL EE E PORT eV EE Y PES a ere Y IET ES aln 19 8 5 Glass D test fi 6 gn Tes ERR 22 8 6 Electrical conductivity of extinguisher discharge ssssseeeneeeene nennen 25 8 7 Class F Test fs kg Ue E ERR aD 26 8 8 ie erre e ne ege E etae aa EE P Eee e rer e inda te dog dens 27 9 Construction feQuireMentS dee eee eu E 27 9 1 High pressure extinguishers
32. crushing when 25 kg is applied to its extremity for 5 min immediately after having completely discharged the extinguisher through the horn Subject the horn to the following test a condition the horn at 55 C for 18 h b attach the horn to a fully charged extinguisher discharge the extinguisher with the valve fully open d subject the horn to a static load of 25 kg using a circular contact surface of 50 mm diameter for 5 min applied at the end of the horn 38 BOS 252 2007 e check that the horn does not show any evidence of cracking or breakage 9 15 Gasket and o rings 9 15 1 Tensile strength elongation maximum set and hardness Any elastomer rubber facing o ring or vulcanized in place seat used to provide a seating surface shall have the following properties a as received 1 minimum tensile strength 3 4 MPa for silicone rubber having polyorgano siloxane as its characteristic constituent or fluorocarbons 8 3 MPa for other elastomers minimum ultimate elongation 100 for silicone rubber and 150 for other elastomers 2 maximum set of 5 0 mm when 25 mm marks are stretched to 50 mm for silicone rubber and 62 5 mm for other elastomers held for 2 min and measured 2 min after release b after 96 h in oxygen at 70 C and at 2 1 MPa 1 minimum percent of original tensile strength 70 2 minimum percent of original elongation 70 The size and shape of a rubber part will determine which of the tes
33. ct gross mass or minimum and maximum gross mass which may be expressed by a tolerance The gross mass shall include the mass of the charged extinguisher and discharge assembly 10 2 2 Operating instructions 10 2 2 1 For the purpose of applying the requirements of this section the operating instructions are defined as those necessary to accomplish intended discharge of the extinguishing media including any warnings An example of the layout marking is given in Figure 6 10 2 2 2 Water based extinguishers with a pH exceeding 9 5 shall contain the following warning or equivalent as part of the operating instructions WARNING Contact of extinguishing agent with eyes or skin may cause permanent damage Immediately flush eyes or skin with clean water 10 2 2 3 The operating instructions shall face outward and cover no more than a 120 arc on the extinguisher body The marking required in 10 2 2 4 and 10 2 3 shall together occupy a minimum surface area of 75 0 cm for an extinguisher having a diameter greater than 80 0 mm and 50 0 cm for and extinguisher having a diameter of 80 0 mm or less 10 2 2 The operating instructions shall be arranged as follows a the word INSTRUCTIONS shall be at the top of the nameplate The minimum letter height shall be 6 0 mm for an extinguisher having a diameter greater than 80 0 mm and 5 0 mm for an extinguisher having a diameter of 80 0 mm or less As an option the words FIRE EXTINGUISHER or EXTINGUISHER m
34. e discharge b If a single action pressurizes the extinguisher and releases the first emission of gas pressurize the extinguisher initially and 3 min later open the control valve again to permit discharge of the extinguishing medium Then close the valve by the action intended to interrupt the emission of the extinguishing medium Measure the internal pressure or in the case of Carbon dioxide CO2 the mass of the extinguisher within 10 s after the control valve has been closed and again after 5 min the control valve having remained closed for the duration of this period 7 4 3 Long term leakage test 7 4 3 1 Requirements for stored pressure extinguishers Stored pressure extinguishers covered by 7 4 1 3 shall not leak at a rate exceeding 5 96 per annum of service pressure BOS 252 2007 7 4 8 2 Requirements for extinguishers checked by mass Long term leakage requirements are as follows a stored pressure extinguishers without a pressure gauge shall not leak at a rate exceeding 5 of its contents per annum or 50 g per annum whichever is less see 7 4 1 2 c b carbon dioxide extinguishers shall not leak at a rate exceeding 5 of its contents per annum 7 4 8 3 Test method Check six samples for leakage after 30 d 90 d and 120 d Any loss in pressure or contents at constant ambient temperature is an indication of a leak 7 5 Mechanical resistance 7 5 1 Resistance to impact NOTE This test is intended to prove the resistan
35. elted fuel depth of 25 mm 1 mm 8 5 4 3 Procedure 8 5 2 5 1 Spill fire Position the square tray on a flat level surface Heat the metal in the covered melting pan until the temperature is 520 C 10 C Carefully remove the cover allowing the liquid metal to ignite as air enters Stop heating when the temperature reaches 550 C 10 C and pour the burning liquid fuel into the square tray As soon as the burning fuel has spread across the tray the fire can be attacked at the operator s discretion using the manufacturer s recommended extinguishing techniques After the discharge is completed allow the fire tray to remain undisturbed for the period of time recommended by the manufacturer or if no time is recommended for 4 h 0 5 h Then using a suitable temperature measuring device check that the fuel extinguishing medium mixture in the tray is at a temperature no more than 20 C above the ambient air temperature and that more than 10 of the original fuel remains 8 5 2 5 2 Pan fire This test is carried out entirely in the melting pan Melt the fuel and allow it to ignite generally as described in 8 5 4 3 1 When the temperature reaches 550 C 10 C move the pan from the heat source and place it on a level floor where it may be attacked at the operator s discretion using the manufacturer s recommended extinguishing techniques After discharge is completed follow the procedure described in 8 5 4 3 1 8 5 5 Simulated casting fire
36. er and the earth when the plate is live and the extinguisher discharging 8 7 Class F test fire 8 7 1 Location Carry out test fires indoors in a draft free room having dimensions of at least 6 m x 6 m 4 m high and at an ambient temperature of not less than 10 C 8 7 2 Construction Class F test fires utilize a range of welded sheet metal trays dimensions are given in Table 11 and Figures 7 and Figure 8 The sides are vertical The base of the trays are set horizontal and level with the surrounding ground or floor Details of Class F fires are given in Table 11 Figure 7 and Figure 8 Each test fire is designated by a number followed by the letter F 8 7 3 Fuel Class F fires shall be conducted using a vegetable oil having an auto ignition temperature of not less than 360 8 7 4 Procedure Fire tests shall be carried out indoors Heat the oil in the test pan using a suitable heating arrangement The oil temperature is to be measured with a thermocouple located 25 mm below the fuel surface and not closer than 75 mm from the walls of the tray The tray shall be heated uncovered at the heating source s maximum input rate The heating arrangement shall demonstrate an average heating rate of not less than 7 C per minute and shall be recorded during the test between the temperature of 260 C and 316 C The oil is to be heated until auto ignition occurs At auto ignition or when the temperature reaches 360 C whichever occurs
37. er mantal meins 41 EE MEET VIS T EP 41 Foreword BOS 252 2007 This Botswana standard was approved by the Technical Advisory Committee of the Standards Council on 2007 05 31 The Botswana Bureau of Standards BOBS was established under the Standards Act No 16 of 1995 with a primary responsibility of preparing Botswana Standards During the preparation of this standard assistance was derived from an International Standard ISO 7165 1999 Fire fighting Portable fire extinguishers Performance and construction During the preparation of this standard the following organizations were directly represented in the Technical Committee MED 6 Fire Safety Ministry of Works Transport and Communications Department of Civil Aviation Botswana Bureau of Standards Afrox Botswana Botsfire Botswana Bureau of Standards Firefighting Products amp Services Ministry of Local Government Gaborone City Council Ministry of Works Transport and Communications Department of Civil Aviation Okavango Electronics ZMCK Consulting Engineers Published by Botswana Bureau of Standards Private Bag BO 48 Gaborone Botswana Telephone 267 3903200 Fax 267 3903120 Email infoc hq bobstandards bw Website www bobstandards bw ICS 13 220 10 Botswana Bureau of Standards 2007 Mr SB Mr Mr T Mr M Mr T Mrs J SJ Mr WT Mr GS Mr S Kgokong Tlhomelang B
38. eveloped in a normally charged and pressurized extinguisher conditioned at 20 C for at least 18 h 3 6 maximum service pressure Pms equilibrium pressure developed in a normally charged and pressurized extinguisher which is conditioned at 55 C for at least 18 h 3 7 complete discharge point in the discharge of an extinguisher when the internal pressure has equalized with the external pressure with the valve control being kept fully open 3 8 effective discharge time time from the commencement of discharge of the extinguishing medium at the nozzle to the gas point of the discharge stream with the control valve fully open 3 9 rechargeable extinguisher extinguisher designed to be recharged after use 3 10 disposable extinguisher non rechargeable extinguisher extinguisher designed not to be recharged in the field or at the factory but intended to be discarded after use 3 11 fill density mass in kilograms of extinguishing medium per litre of container volume as fitted for use complete with valve and internal fittings 3 12 bulk range range of the extinguisher when 50 of its media has been expelled 3 13 batch group of the same products made on the same production line using the same lot of materials during one production shift 3 14 gas point point where the medium discharge changes from predominately liquid medium to predominately expellant gas 3 15 propellant non flammable compressed gas used to expel the extinguishing medium 3
39. fires 708 1138 1838 represent the product of the preceding term and 41 62 a 1 3 water and 2 3 heptane b Measured at rim This fire size is for a low temperature fire test only 8 4 4 Procedure Add the appropriate volume of water and heptane specified in Table 9 Add additional water to compensate for distortion of the base so that all points are covered subject to a maximum liquid depth of 50 mm anda minimum heptane depth of 15 mm at any point For water based and clean agent extinguishers fresh fuel and water shall be used for each test For CO type extinguishers and powder type extinguishers when a fire test filled with fresh fuel and water 21 BOS 252 2007 has been successfully extinguished with the tested extinguisher then fuel shall be added once for the next test When testing powder extinguishers it shall be demonstrable that the rating can be achieved using fresh fuel Ignite the fuel Permit the fuel to burn freely for a minimum of 60 s before operating the extinguisher The operator shall then bring the extinguisher into use within no more than 10 s after the 60 s pre burn period and direct the jet onto the test fire NOTE 1 The extinguisher may be discharged continuously or in intermittent bursts at the discretion of the operator The operator may move round the fire in order to obtain the best results NOTE 2 For reasons of safety the operator shall not reach over the edge of the tray and at no time shal
40. fires for which the extinguisher is not intended for use because of potential injury to the operator the use code symbols with a red slash shall also be placed on the extinguisher The red slash shall be from the top left corner of the symbol to the bottom right corner 10 2 3 4 The manufacturer s name or trade name may be placed below the use code symbols but shall not contain any other information that would distract attention from the operating instructions such as an address or telephone number 10 2 4 Recharging instructions The recharging instructions on the marking of a rechargeable extinguisher shall state the intended mass and agent that shall be used in recharging and the intended expellant gas pressure Reference shall be made to use only the manufacturer s replacement parts in recharging the extinguisher However in lieu of detailed recharge instructions these instructions may simply instruct the user to return the extinguisher to the dealer or manufacturer for recharging using the following words or the equivalent Return to an authorized recharger for recharging in accordance with Service Manual No 10 3 Inspection instructions The inspection instructions shall state that the extinguisher is to be checked to ensure that a the seals and tamper indicators are not broken or missing b itis full by weighing or lifting C itis not obviously damaged corroded leaking or has a clogged nozzle d its pressure gauge readi
41. gauge shall have a pressure relief that will vent in the event of a Bourdon tube leak This pressure relief shall function at a pressure of 345 kPa or less within 24 h The minimum flow capacity of the pressure relief shall be 1 l h Conduct this test on pressure gauges with the Bourdon tube cut completely through Immerse the gauge in water with the gauge inlet connected to a regulated source of air or nitrogen Maintain the supply pressure at 345 kPa until the pressure relief functions or for 24 h whichever is shorter Measure the flow rate with an inverted water column or other equivalent means 9 12 7 Water resistance test gauges and indicators A gauge or indicator for use on an extinguisher shall remain watertight after being immersed at a depth of 0 3 m in water for 2 h and after being subjected to the salt spray corrosion test see 7 6 1 9 12 8 Leakage test gauges and indicators 9 12 8 1 A pressure gauge or indicator shall not leak at a rate in excess of 1 x 10 cm s when the gauge or indicator including a pin type indicator is exposed to a pressure equivalent to the intended service pressure of the extinguisher at 20 C 9 12 8 2 A leak detection apparatus and leak standard are to be used to verify compliance with the requirements specified in 9 12 8 1 The leak detection apparatus is to be capable of signaling and the leak standard capable of generating a leakage rate of 1 x 105 cm3 s 9 12 8 3 Apply a pressure equivalent to t
42. ght it shall conform to 9 12 2 and 9 12 7 d there shall be no corrosion of the metal of the extinguisher body discoloration or superficial corrosion of non ferrous metals is acceptable but galvanic corrosion between dissimilar metals shall not be permitted e when tested in accordance with 9 9 3 the burst pressure of the hose shall be as specified 7 6 2 Internal corrosion test for extinguishers using water based media Subject two extinguishers charged in accordance with the manufacturer s filling instructions eight times to the temperature cycle defined in Table 3 Table 3 Temperature cycle BOS 252 2007 Stage Duration Temperature h C 1 24 1 2 24 2045 3 24 t 1 55 2 4 24 20 5 NoteThe temperature refers to the ambient temperature of the conditioning chamber A liquid bath shall not be used The duration of anyone complete cycle shall not exceed 120 h a The lowest temperature marked on the extinguisher 2 C See 7 1 On completion of the eight temperature cycles cut each body into two sections in a manner sufficient to permit internal examination Disregard detachment of any protective coating local to the plane of section There shall be no visible signs of corrosion of the metal nor detachment cracking or bubbling of any protective coating There shall be no visible change in the colour of the extinguishing media other than that resulting from the thermal cycling Allowance sho
43. guish the fire of maximum size under the conditions of the test This amount shall be no less than the appropriate minimum value given in Table 4 BOS 252 2007 Table 4 Amount of extinguishing medium used to obtain a minimum Class A rating of extinguishers Extinguishing medium content charge Minimum Class A rating Powder Water foam Clean agent kg Water with additives kg Is2 Is6 Is6 1A 2 ls4 6 1s10 6 1s8 2A 4 1Is6 I Is 10 1 gt 8 3A 6 lt Is9 4A 1 gt 9 6A 8 1 2 Class B The rating of extinguishers recommended as suitable for Class B fires shall be determined using the method given in 8 4 The rating shall be based on the amount of extinguishing medium used to extinguish the fire of maximum size under the conditions of the test This amount shall be no less than the appropriate minimum value given in Table 5 Table 5 Amount of extinguishing medium used to obtain minimum Class B rating of extinguishers Extinguishing medium content charge Minimum Class B rating Powder Carbon dioxide Clean agent Foam or water with additives kg kg kg Is2 Is2 Is2 21B 2 lt 1 lt 3 2 lt ls5 2 s4 34B 3 Is4 55 4 Is6 Is6 55B 4 Is6 1 gt 6 6 1Is9 89B 1 gt 6 1 gt 9 144B 8 1 5 Class C There are no test requirements for the performance of extinguishers against Class C fires included in this standard Suitability for use against Class C may be claimed for Class
44. guishing medium with which it can be used Pressure gauge markings shall be subjected to UV testing as specified in 9 8 3 There shall be no significant deterioration of the legibility such as darkening fogging or fading upon completion of the UV testing 9 12 1 7 The pressure gauge shall be marked with the gauge manufacturer s identifying mark The pressure gauge shall also be marked according to the following if applicable using a line extending as wide as and of the same stroke thickness as the manufacturer s identifying mark a to indicate galvanic compatibility with aluminium valve bodies a horizontal line above the manufacturer s identifying mark b to indicate galvanic compatibility with brass valve bodies a horizontal line below the manufacturer s 36 BOS 252 2007 identifying mark to indicate galvanic compatibility with aluminium and brass valve bodies a line above and a line below the manufacturer s identifying mark 9 12 2 Calibration test gauges and indicators 9 12 2 1 An indicator shall be accurate to within 4 of the service pressure Ps at the lower limit of the operable range 9 12 2 2 The error of a pressure gauge at the indicated service pressure Ps shall not exceed 4 of the service pressure The error at the upper and lower limits of the operable range shall not exceed the following percentages of the service pressure a t 4 96 for powder and water based extinguisher gauges and b t
45. hall be subjected to the test specified in 7 5 2 5 3 Extinguishers supplied with a bracket suitable for both general and vehicle use shall be subjected to the test specified in 7 5 2 5 3 Complete the tests specified in a and b above in one plane before making tests in the next plane 7 5 2 3 Test criteria The test criteria are as follows a following exposure to the vibration test the extinguisher shall comply with the discharge requirements specified in 7 2 b physical failure of components which would require repair or replacement of the extinguisher and or components before it can be returned to normal service shall be cause for rejection 7 5 2 4 Mounting of the test specimen Mount a fully charged extinguisher in an upright position Mount extinguishers intended for use in vehicles in their intended bracket Extinguishers not intended for use in vehicles may be tested without a bracket 7 5 2 5 Test orientation 7 5 2 5 4 Axes of orientation Subject the extinguisher to the vibration test specified in 7 5 2 5 2 or 7 5 2 5 3 in each of the three rectilinear axes in the following order horizontal lateral and vertical 7 5 2 5 2 General extinguishers The vibration applied shall have the following parameters Frequency 40 Amplitude 0 25 mm 0 03 mm Duration 2 h in each orientation specified in 7 5 2 5 1 7 5 2 5 8 Vehicle extinguishers Subject the vehicle extinguishers to the following tests BOS 252 2007 a
46. he intended working pressure of the extinguisher at 20 C to each of twelve sample gauges or indicators Subject each sample gauge or indicator other than a pin type indicator to a leak test by checking all pressurized components for leakage in order to verify compliance with the requirements in 9 12 8 1 Test each pin type indicator for leakage by checking the opening sealed by the indicator for leakage None of the samples shall exhibit leakage at a rate in excess of 1 x 10 6 cm3 s 9 12 9 Plastics components gauges and indicators Plastic components of gauges and indicators shall meet the requirements given in 9 8 9 13 Dip tubes and filters water based extinguishers 9 13 1 The dip tube and filter of water based extinguishers shall be constructed of materials resistant to the extinguishing medium See 9 8 6 9 13 2 The extinguishing medium from water based extinguishers shall be discharged through a filter The filter shall be placed upstream of the smallest section of the discharge passage Each orifice of the filter shall have an area less than that of the smallest cross section of the discharge passage The total area of the combined filter orifices shall be at least equal to five times the smallest section of the discharge passage The filter shall be accessible to facilitate maintenance operations on the portable fire extinguisher 9 14 Special requirements for CO2 extinguishers The extinguisher horn shall be constructed to withstand
47. hout leakage failure or visible deformation 9 7 2 Leakage tests Each stored pressure and carbon dioxide extinguisher shall be subjected to a leakage test and comply with the following requirements a for stored pressure extinguishers fitted with a gauge as specified in 7 4 1 3 the leakage rate shall not exceed a rate of loss of pressurizing content equivalent to 5 per annum of service pressure b for stored pressure extinguishers without gauges as specified in 7 4 1 2 the maximum loss of contents per annum shall not exceed the following 1 for extinguishers 5 or 50 g whichever is less 2 for gas cartridges 5 or 7 g whichever is less for carbon dioxide extinguishers the maximum loss of contents shall not exceed 5 per annum 9 8 Requirements for plastics components 9 81 General requirements 9 8 1 1 Plastics components of portable fire extinguishers shall comply with the following requirements The test and conformity checks shall be carried out on components which correspond to the mass produced components in respect of the material used the form and the method of manufacture 9 8 1 2 It is recommended that the plastic used be identifiable at all times Any change in the material the form or the method of manufacture requires a new test 32 BOS 252 2007 9 8 1 2 It is necessary to have access to data supplied by the manufacturer relating both to the material itself and the manufacturing procedures 9 8 1
48. hundred times from a height of 15 mm at a frequency of 1 Hz onto a rigid horizontal steel plate The extinguisher is to be removed from the test apparatus with a minimum amount of agitation held in its normal working position and operated Unless otherwise specified for this particular test testing shall be carried out at a temperature of 20 C 5 Portable fire extinguishers for testing shall be stored for at least 18 h at a temperature of 20 C 5 C before the tests are carried out and shall be maintained within this temperature range until tested 7 8 Intermittent discharge test An extinguisher conditioned at its minimum operating temperature 2 C and at 55 C 2 shall operate in such a manner that for the first discharge not more than 5 s elapses from the time the control valve is opened until the extinguishing media starts to discharge and 1 s for the other discharges Additionally at the end of discharge the extinguisher shall not retain more than the following percentages of its original charge powder 15 all others 10 Carry out testing on four extinguishers Before testing weigh each extinguisher then subject two extinguishers to the minimum operating temperature and subject the other two extinguishers to 55 C 2 C Storage at the temperatures specified shall be carried out in conditioning chambers Liquid baths shall not be used Extinguishers shall remain upright during the temperature condition
49. indrical part of the body 9 2 1 8 Determination of maximum service pressure Pms 9 2 1 8 1 Conduct the test on a minimum of three extinguishers conditioned at 55 C for 18 h 9 2 1 8 2 For stored pressure type extinguishers determine the pressure immediately after taking each extinguisher out of the oven For cartridge operated type extinguishers remove each extinguisher from the oven and activate the cartridge immediately 9 2 1 8 3 For each type of extinguisher the highest pressure observed during 9 2 1 8 2 is recorded as the maximum service pressure Pm 9 2 2 Burst test 9 2 2 1 Fill the extinguisher with a suitable liquid and increase the pressure at a rate not exceeding 2 0 MPa min 0 2 MPa min 20 bar min 2 bar min until the minimum burst pressure Pb is achieved Maintain this pressure for 1 min without the cylinder rupturing Increase the pressure until rupture occurs The minimum burst pressure Pp shall be 2 7 x Pms but in no case less than 5 5 MPa 55 bar 9 2 2 2 The bursting test shall not cause the cylinder to fragment 9 2 2 3 The break shall not show any sign of brittleness that is the edges of the break shall not be radial but shall be slanting in respect of a diametrical plane and shall exhibit a reduction in area over their entire thickness 9 2 2 4 The break shall not show any characterized defect in the metal 9 2 2 5 The break shall not occur in the weld at a pressure less than 5 4 x Pms or 8 0 MPa 8
50. ing The tolerances given shall be considered nominal tolerances with the climatic chamber empty Operate the extinguisher within 2 min of its removal from the conditioning chamber The extinguisher shall be operated in accordance with 7 8 2 Measure and record the time between the opening of the final control valve and the commencement of discharge Reweigh the extinguisher and record the residual charge All four extinguishers shall pass the test BOS 252 2007 Key NO WD A HA j i MEVS s MER HN Nd 6 PE wiih TH HF VA HH UE D Al 10 Castor support axis 8 Castor Castors 9 Cam Cl C M12 190 screw 10 Inductive pick up Push nut extinguisher 11 Rotation guidance H M16 90 screw 12 Axes Plates 13 Castor nut Piston 14 Support plate 15 16 17 18 19 Adjusting block Support axes Plate support axis Flender Himmel geared motor System support plate Figure 1 a Tapping machine General diagram BOS 252 2007 Figure 1 c Tapping machine Details of item 9 in Figure 1 8 Performance requirements for test fires 8 1 Rating suitability for the various classes of fire 8 11 Class A The rating of extinguishers recommended as suitable for Class A fires shall be determined using the method described in 8 3 The rating shall be based on the amount of extinguishing medium used to extin
51. l the operator step onto or into the tray 8 4 5 Low temperature extinguishment test An extinguisher charged with its rated capacity of extinguishing agent and expellant gas and conditioned at the minimum storage temperature for 18 h shall extinguish a Class B test fire two classification sizes smaller than the rating of the extinguisher given in Table 9 Before testing weigh the extinguisher then subject the extinguisher to the minimum operating temperature 2 for a period of 18 h Storage at the specified temperature shall be carried out in conditioning chambers Liquid baths shall not be used The extinguisher shall remain upright during temperature conditioning The tolerances 2 C shall be considered nominal tolerances with the climatic chamber empty The test shall be conducted within 5 min of removal of the extinguisher from the conditioning chamber 8 5 Class D test fire 8 5 1 General The extinguishment of these test fires is based on the use of a portable extinguisher having a nominal charge of 13 6 kg of media Extinguishers having a lesser charge shall be tested using a proportionally reduced quantity and surface area of fuels Extinguishers with a charge of less than 8 kg shall not be allowed WARNING Some extinguishing media used for Class D fires are toxic for example barium chloride 2 and or may react with the burning metal to produce materials which are toxic or otherwise hazardous for example pho
52. last the fire is to burn freely with the energy source remaining on for 1 minute After 1 minute freeburn the extinguisher is to be discharged onto the tray continuously or intermittently until the extinguisher is fully discharged The heat source to the 26 BOS 252 2007 tray is to remain on during discharge The initial discharge of the extinguisher onto the fryer shall be at the distance specified in the instructions and the extinguisher nozzle shall not extend over the front edge of the tray during discharge Turn off the heat source at the end of the extinguisher discharge Use fresh fuel for each test 8 8 Class F splash test 8 8 1 General An extinguisher shall not splash grease droplets in excess of 5 mm diameter when tested as described in 8 8 5 8 8 5 8 8 2 Procedure Use the same fire test tray as specified in Table 11 The test tray is to be constructed as shown in Figure 7 or Figure 8 The test tray is to be filled with liquid vegetable oil until it is 75b mm below the top edge of the tray The oil level is to be measured when the oil temperature is between 175 C 190 C The oil temperature during the test is to be measured with a thermocouple as described in 8 7 4 Use two extinguishers for the test Each extinguisher is to be charged to its rated capacity of extinguishing agent and expellant gas One extinguisher shall be conditioned to its maximum storage temperature for 18 hrs The second extinguisher shall be condi
53. nal metal fuel remains 8 5 8 Metal powder or dust fires 8 5 3 1 Construction Construct the fires in the same manner as the metal chip fires see 8 5 2 1 8 5 3 2 Fuel Use magnesium powder containing not less than 99 5 magnesium All the particles shall pass a 387 um sieve and no less than 80 96 of the powder shall be retained on a 150 um sieve Carry out two series of tests one series using 11 0 kg 0 1 kg of dry metal and one series using 9 9 kg 0 1 kg of the metal plus 1 1 kg 0 1 kg of the oil specified in 8 5 2 2 for each fire 23 BOS 252 2007 8 5 3 3 Procedure Carry out the tests using the same procedure as the metal chip fires in 8 5 2 3 8 5 4 Shallow liquid metal fires 8 5 4 1 Construction Two series of tests are carried out One series will be carried out in a circular steel pan approximately 540 mm in diameter and 150 mm 10 mm deep fitted with a tight fitting cover and with suitable means of handling moving and tipping and with a horizontal thermocouple to be positioned in the approximate centre of the pan This pan is also used to melt the metal fuel using a heat source which does not allow any flames to extend beyond the base of the pan In the second series melted burning fuel is poured on a tray approximately 600 mm x 600 mm square and having a depth of 155 mm 5 mm 8 5 4 2 Fuel Use commercial sodium Use 1 36 kg 0 04 kg of sodium for the spill fire and for the pan fire sufficient sodium to give a m
54. nd of square cross section with sides of 39 mm 1 mm a moisture content of 10 to 14 by mass dry basis NOTE 1 Wood is considered to be equivalent if the rating achieved using wood that is not more than that achieved when Pin us Sylvestris is used In North America mixed spruce pine fir lumber which may include Picea Glauca Picea Engelmannii Pinus Contorta and Abies Lasioscapa or Pinus Banksiana Picea Rubens Picea Maraina and Abies Balsamea depending on geographical location may be used Cryptomeria Japonica may be preferred in parts of Asia NOTE 2 Determine the moisture content of the pieces of wood using commercially available instruments which measure electrical conductivity between needle probes pushed into the sticks or other suitable method Some variation in BOS 252 2007 reading may be obtained due to structural variation of the timber and the direction of the grain Calibrate the instrument by determination of moisture content in accordance with ISO 3130 Table 7 Wood crib construction Class A rating Number of Length of pieces Arrangement of pieces of wood pieces of wood of wood mm 1A 72 500 12 layers of 6 pieces of wood 2A 112 635 16 layers of 7 pieces of wood 3A 144 735 18 layers of 8 pieces of wood 4A 180 800 20 layers of 9 pieces of wood 6A 230 925 23 layers of 10 pieces of wood 10A 324 1100 27 layers of 12 pieces of wood 15A 450 1190 30 layers of 15 pieces of wood 20A 561
55. ng or indicator is in the operable range or position 11 Manuals 11 14 User manual A user manual shall be provided with each extinguisher This manual shall contain the necessary instructions warnings and cautions for the intended installation operation and inspection of the extinguisher The manual shall also reference the manufacturer s service manual for maintenance and recharging of the extinguisher 11 2 Service manual The manufacturer shall prepare a service manual for each model fire extinguisher It shall be made available upon request and shall 8 contain necessary instruction warnings and cautions a description of servicing equipment and a description of recommended operations for intended servicing b provide a list of part numbers of all replaceable parts c indicate that the pressure gauge attached to the extinguisher shall not be used to determine when the intended service pressure has been reached and a pressure regulator shall be used if the pressure service is a tank of high pressure gas 41 2007 BOS 252 993 00 93N AWVN 93A ut 1300W ta 02 01 031531 345534 3 906 dy OF 9 60 OL 2 087 WOH4 3001vd34A31 LY ISN 803 311 6 W3HSInONILX3 394 IOIKOIONOGHYD 5y 2 QUVONY LS OS S133 YXOO0CXX 8 12 NOILVOI3ISSY1O 3 3 3814 30IXOIQ NOGHYO Bv WAQHdd 301S 01 3018 4335 38 40 3SVB LV NIY 43A31 3733 05 We WOVE LUVLS 6
56. nguisher and its mounting bracket shall not be sufficiently sharp to constitute a risk of injury to persons during intended use or while performing maintenance NOTE One method of evaluating sharpness of edges is described in ANSI UL 1439 other methods are acceptable 9 6 Safety devices 9 6 1 High pressure cylinders and cartridges shall be provided with a safety device in accordance with national regulations 9 6 2 There are no compulsory safety systems required for low pressure extinguishers However if such a system is used it must be appropriately sized and positioned The operating pressure of the device shall not exceed the test pressure Pt nor be less than the maximum service pressure Pms 9 7 Manufacturing tests 9 7 1 Low pressure cylinders 9 7 1 1 At least one cylinder from each batch of 500 or less shall be subjected to the crush and burst tests If the test results are not acceptable randomly select five additional cylinders from the same batch and repeat the tests If one of the cylinders does not pass the test the batch is rejected and made unserviceable At the option of the manufacturer the burst and crushing test may be conducted on the same cylinder If a cylinder that has successfully passed the crushing test fails the burst test it shall not be considered as a failure and another one from the same batch can be utilized for the burst test 9 7 1 2 Each cylinder shall be subjected to the test pressure P for 30 s wit
57. ning of paint directly on the extinguisher body The marking shall identify the extinguisher as to type of media and shall include the manufacturer s name and model number and the rating and classification of the fire extinguisher 10 2 1 2 The marking shall include a sequential serial number 10 2 4 3 The year of manufacture or the last two digits of the calendar year and the factory test pressure shall be permanently marked into the extinguisher body or non transferable nameplate Extinguishers 39 BOS 252 2007 manufactured in the last three months of a calendar year may be marked with the following year as the date of manufacture and extinguishers manufactured in the first three months of a calendar year may be marked with the previous year as the date of manufacture 10 2 1 4 lf a manufacturer produces extinguishers at more than one factory each extinguisher shall have a distinctive marking to identify it as the product of a particular factory 10 2 4 5 The marking shall include a reference to the range of temperatures at which the extinguisher is usable such as Acceptable to use at temperature from to or the equivalent 10 2 1 6 The following applicable statement or the equivalent shall be included in the marking for rechargeable extinguishers Recharge immediately after any use for disposable extinguishers Discard immediately after any use 10 2 1 7 The marking on each extinguisher shall include its exa
58. ontinuous penetration with no deviation in the weld Welds and brazed joints shall be free from defects which are prejudicial to the safe use of the cylinder All welders weld operators and weld procedures shall be qualified and certified by an independent third party recognized by national authorities All welders weld operators and weld procedures shall be qualified and certified by an independent third party recognized by national authorities 9 2 1 4 Parts attached to the body of the extinguisher shall be manufactured and fitted in a way that minimize concentrations of stress and corrosion risks In the case of welded and brazed parts the metal shall be 27 BOS 252 2007 compatible with the cylinder material 9 2 1 5 The cylinder manufacturer shall obtain the works certificate for the cast analysis of material supplied and shall keep this available for inspection 9 2 1 6 Where plastic components are threaded into metallic parts they shall be designed to minimize the possibility of cross threading This shall be accomplished by the use of coarse threads of less than five threads per centimetre or by the use of square cut threads 9 2 1 7 Extinguishers which are free standing shall either be fitted with a means to raise the pressure retaining part of the body at least 5 mm above the floor or the thickness of metal in the lowest pressure retaining part or parts of the body shall not be less than 1 5 times the minimum thickness of the cyl
59. ord the pressure at which the hose bursts 9 9 10 A hose assembly without a shutoff nozzle shall be capable of withstanding without leakage a hydrostatic pressure equal to the extinguisher test pressure P held for at least 30 s 9 10 Method of operation The extinguisher shall be operated by piercing opening and or breaking a sealing device thus releasing its contents Extinguishers shall operate without inversion It shall not be necessary for any movement of the actuating mechanism to be repeated in order to initiate discharge of the extinguisher The forces or the energy necessary to operate the extinguisher shall not exceed the values in Table 10 for temperatures up to 55 C The energy of 2 J is obtained by allowing the 4 kg mass used in the mechanical resistance impact test described in 7 5 to fall from a height of 50 mm The impact shall be applied in the direction of the operating mode Table 10 Force or energy required to operate the extinguisher Type of operation Maximum force required Energy N With one finger 100 With full hand 2003 With impact strike knob 2 a For carbon dioxide extinguishers this maximum force may be increased to 300 N 9 11 Safety locking devices 9 11 1 The operating mechanism shall be provided with a safety device to prevent inadvertent operation The release of the safety device with tamper indicator shall involve an operation distinct from that of the operation mech
60. oshoff Bishop Phirinyane Fraser Chinoganhira Ntshimane Clarke Kentshitswe Chairperson Technical Secretary BOS 252 2007 Fire fighting Portable fire extinguishers Performance and construction 1 Scope This Standard specifies the principal requirements intended to ensure the safety reliability and performance of portable fire extinguishers It is applicable to a fully charged extinguisher having a maximum mass of 20 kg NOTE 1 In some cases extinguishers having a total mass of up to 25 kg when fully charged may be approved subject to local acceptance NOTE 2 Cartridge type fire extinguishers are not recommended for use hence not covered in the standard 2 Normative references The following normative documents are indispensable for the application of this standard For dated references only the edition cited applies For undated references the latest edition of the referenced document including any amendments applies Botswana Bureau of Standards BOBS maintains registers of currently valid standards ANSI UL 1439 Safety Standard for the Determination of Edges on Equipment BOS ISO 3941 Classification of fires BOS ISO 5923 Fire protection Fire extinguishing media Carbon dioxide BOS ISO 7202 Fire protection Fire extinguishing media Powder BOS ISO 7203 all parts Fire extinguishing media Foam concentrates ISO 3130 Wood Determination of moisture content for physical and mechanical
61. r at least 18 h at a temperature of 20 C 5 C before the tests are carried out and shall be maintained within this temperature range until tested Weigh the extinguisher Hold the extinguisher in its normal working position i e hand held and keep it immobile for the duration of the test For extinguishers which are activated by a single operation of the control valve open the control valve and leave open for the duration of the test Measure and record the time between the opening of the final control valve and the commencement of discharge Measure and record the effective discharge time Reweigh the extinguisher calculate and record the residual charge All portable fire extinguishers shall operate within 5 s of the final control valve being opened 7 2 8 Bulk range 7 2 3 1 Requirements The minimum bulk range of extinguishers with a Class A rating shall be no less than 3 m when determined in accordance with 7 2 3 2 BOS 252 2007 7 2 3 2 Test method Carry out the test indoors using lighting which gives the best possible illumination of the extinguisher media during discharge Use a black background marked to indicate the horizontal distance Condition the extinguisher for no less than 18 h at a temperature of 20 C 5 C and place it in normal operating position with the discharge nozzle held horizontally 1 m above the floor Fully discharge the extinguisher with the control valve fully open within 2 min of conditioning
62. re activated by a single operation of the control valve open the control valve and leave open for the duration of the test Measure and record the time between the opening of the final control valve and the commencement of discharge then measure and record the effective discharge time Reweigh the extinguisher calculate and record the residual charge All portable fire extinguishers shall operate within 5 s of the final control valve being opened 7 2 2 Class B rated extinguishers 7 2 2 1 Effective discharge The minimum effective discharge time of extinguishers with a Class B rating shall be no less than the appropriate value given in Table 1 BOS 252 2007 Table 1 Minimum effective discharge time of Class B rated extinguishers Classification Minimum discharge time S 8B 1988 218 8 34B 8 55B 9 70B 9 89B 9 113B 12 144B 15 183B 15 233B 15 7 2 2 2 Requirements When three portable fire extinguishers are tested as follows the duration of operation of each extinguisher shall be within 3 s of the average value for powder extinguishers and within 15 of the average value for other extinguishers but the duration value shall not be less than the minimum specified 7 2 2 3 Test method Testing of portable extinguishers shall be carried out within 2 min of removal of the extinguisher from the conditioning temperature Portable fire extinguishers for testing shall be stored in a vertical position fo
63. rnal pressure at 20 C 2 C For this purpose the extinguisher shall be fitted with a built in pressure indicating device which can be checked for satisfactory operation A connection to which an independent pressure measuring appliance can be attached may be used as the means for checking the built in pressure indicating device in this case a connection of this type shall be equipped with a pressure retaining cap 7 4 2 Retention of charge following partial discharge 7 4 2 1 Requirements Fire extinguishers shall be fitted with a control valve allowing the discharge of the extinguishing medium to be interrupted at any time The extinguisher shall be adequately resistant to leakage and the second pressure or weight of contents as appropriate shall be no less than 75 of the first after interruption of the discharge as determined in 7 4 2 2 7 4 2 2 Test method This test shall be carried out with three extinguishers conditioned for 18 h at 20 C 5 C All three extinguishers shall pass the test Operate the extinguishers and allow the medium to discharge for one half of the measured discharge duration For extinguishers with a propellant gas cartridge open the control valve in accordance with a or b below as applicable a8 If the extinguisher is fitted with a pressurization device independent of the device which opens the control valve operate the pressurization device and 3 min later open the control valve to initiat
64. rrent of more than 0 5 mA when tested as described in 8 6 3 Water based models which may be produced with or without an antifreeze agent shall be treated as separate and distinct models for the electrical conductivity test 8 6 20 Requirements Test the extinguisher in accordance with 8 6 3 When the extinguisher is in operation and the metallic plate is live the current between the handle or the nozzle and earth and between earth and the extinguisher shall be no more than 0 5 mA at any time during the complete discharge duration of the extinguisher 8 6 8 Test for electrical conductivity Hang a metal plate of dimensions 1 m 25 mm by 1 m 25 mm vertically from insulating supports Connect the plate to a transformer so that an alternating voltage of 36 kV 3 6 kV is established between the plate and earth The impedance of the circuit should be such that when a voltage equal to 10 of the normal primary voltage is applied to the primary and the secondary is short circuited the current in the secondary is not less than 0 1 mA Mount the extinguisher on an insulating support with the nozzle fixed 1 m from the centre of the plate at right angles to it and directed towards it Connect the extinguisher to the earth In the case of an extinguisher with a hose connect it to the earth by connection at the nozzle or in the case of an extinguisher not fitted with a hose by connection at the handle Measure any current flowing between the extinguish
65. sphates which react to form metal phosphides which are decomposed by water to produce phosphine PHs a spontaneously flammable gas Before carrying out these tests establish procedures to protect personnel and to safely dispose of residues from test fires Conduct the tests in an essentially draught free room having adequate volume and ventilation to ensure the necessary visibility for the period of the test There are no numerical components for Class D ratings The type of combustible metal for which the extinguisher is applicable and the area depth and other characteristics of the fires which may be controlled and extinguished are to be summarized on the extinguisher nameplate and described in the manufacturer s installation instructions 22 BOS 252 2007 8 5 2 Metal chip or turning fires 8 5 2 1 Construction The fires consist of a bed of the metal fuel 600 mm x 600 mm square positioned centrally on a steel baseplate 1mx 1m square and 5 mm thick Use a removable metal or wood frame to build the bed For ignition use a device such as a gas oxygen torch which will ignite the metal within 30 s 8 5 2 2 Fuel Carry out four series of tests using a magnesium alloy b magnesium alloy with cutting oil reagent grade magnesium d reagent grade magnesium with cutting oil The magnesium alloy shall contain 8 5 96 1 96 of aluminium and at maximum 2 5 96 zinc and the nominal particle size shall be 10 mm to 25 mm long 6 mm
66. ssure Pp shall be at least equal to that specified for the cylinder 9 8 8 Ultraviolet light exposure 9 8 3 1 Subject at least six components to an artificial weathering test in accordance with 9 8 3 4 for 500 h and then condition them for 5 h at 20 5 C 9 8 3 2 Following the exposure inspect the samples for cracking No cracking shall be permitted 9 8 3 3 Subject the components to the burst test in accordance with 9 2 2 at 20 C 5 C using a suitable liquid at a rate of pressure increase of 2 0 MPa min 0 2 MPa min 20 bar min 2 bar min The bursting pressure Pp shall be at least equal to that specified for the cylinder 9 8 3 4 Use two stationary enclosed carbon arc lamps to obtain the ultraviolet light The arc of each lamp is to be formed between two vertical carbon electrodes 12 7 mm in diameter located at the centre of a removable vertical metal cylinder 787 mm in diameter and 450 mm in height Enclose each arc in a clear borosilicate glass globe Mount the samples vertically on the inside of the revolvable cylinder facing the lamps and revolve the cylinder continuously around the stationary lamps at 1 rev min Provide a system of nozzles so as to spray each sample in turn with water as the cylinder revolves During each operating cycle total of 20 min expose each sample to the light and water spray for 3 min and to the light only for 17 min Maintain the air temperature within the revolving cylinder of the apparat
67. st cage and apply pressure at a rate of approximately 2 0 MPa min until the required test pressure is reached Hold the pressure is to be held at this point for 1 min then increase the pressure until rupture occurs or eight times the indicated service pressure is reached whichever occurs first 9 12 4 Overpressure test gauges The difference in readings of indicated service pressure before and after a pressure gauge has been subjected for 3 h to a pressure of 110 of the indicated gauge capacity shall not exceed 4 of the indicated service pressure Subject sample pressure gauges to the required test pressure for 3 h Then release the pressure and allow the gauges to stand at zero pressure for 1 h Subject the gauges to the calibration test described in 9 12 2 9 12 5 Impulse test gauges 9 12 5 1 The difference in readings of indicated service pressure before and after a pressure gauge is subjected to 1 000 cycles of pressure impulse shall not exceed 4 of the indicated service pressure 9 12 5 2 Attach sample pressure gauges to a regulated source of pressure either air nitrogen or water Vary the pressure from 0 96 to 125 96 of the indicated service pressure or 0 to 60 96 of the gauge capacity whichever is higher and then back to 0 at a rate of six complete cycles each minute The samples then are to be subjected to the calibration test described in 9 12 2 37 BOS 252 2007 9 12 6 Pressure gauge relief test A pressure
68. tests ISO 4892 2 Plastics Methods of exposure to laboratory light sources Part 2 Xenon arc sources ISO 9227 Corrosion tests in artificial atmospheres Salt spray tests ISO 14520 all parts Gaseous fire extinguishing systems Physical properties and system design 3 Terms and definitions For the purposes of this standard the following terms and definitions apply 3 1 Classification of fires 3 4 1 Class A fires involving solid materials usually of an organic nature in which combustion normally takes place with the formation of glowing embers 3 1 2 Class B fires involving liquids or liquefiable solids 3 1 3 Class C fires involving gases 3 1 4 Class D fires involving metals 3 1 5 Class F fires in cooking appliances that involve combustible cooking media vegetable or animal oils and fats BOS 252 2007 3 2 portable extinguisher portable appliance containing an extinguishing medium which may be discharged and directed onto a fire by the action of internal pressure The discharge is achieved by stored pressure constant pressurization of the extinguishing media container 3 3 extinguishing medium substance contained in the extinguisher that causes extinguishment 3 4 charge of extinguisher mass or volume of the extinguishing medium contained in the extinguisher expressed in volume litres for water based extinguishers and in mass kilograms for other extinguishers 3 5 service pressure Ps equilibrium pressure d
69. th a flue area of 4 5 m have been found to provide adequate ventilation NOTE For example it has been established that a room having a ceiling height of approximately 7 5 m and a volume of at least 1 700 m with adjustable inlet openings near the four corners is suitable for these purposes The room should have a smoothly finished concrete floor Table 6 Example of typical air inlet sizes for ventilation of Class A test fires Classification and Air inlet opening surface area rating m 1A 0 10 2A 0 10 3A 0 15 4A 0 20 6A 0 30 10A 0 50 15A 0 75 20A 1 00 8 3 2 Construction The test fire consists of a crib made of pieces of wood The pieces of wood forming the outside edges of the crib may be stapled or nailed together to provide strength Construct the crib on two 63 mm x 38 mm angle irons or other similar and appropriate supports placed on concrete blocks or support frame so as the height of the supports above the floor is 400 mm 10 mm Stack the pieces of wood in the appropriate arrangement specified in Table 7 Stack each layer of the pieces of wood at right angles to the layer below Stack individual pieces of wood on each layer with even spacing and in the form of a square with sides equal to the length of the piece of wood see Figure 2 Use pieces of wood of Pinus Sylvestris or of other wood which can be shown to be equivalent of appropriate length as specified in Table 7 a
70. th a strap shall not permit the extinguisher to drop to the floor when the strap clamp is opened The clamp releasing device shall be of a colour contrasting with that of the immediate extinguisher background and shall be visible The method of release shall be obvious when viewing the front of the extinguisher 9 4 6 A hanger loop shall be located so that the operating instructions face outward when the extinguisher is supported by the mounting means 9 5 Caps valves and closures 9 5 1 Cylinder caps valves and closures shall be designed to provide release of pressure before complete disengagement 9 5 2 Threaded connections on cylinder shall have at least four full threads of engagement and be required to relieve pressure with at least two full threads of engagement Other types of valves caps and closures are permissible if they can satisfy the same requirements particularly with regard to recurrent tests and filling 9 5 3 The inside diameter of a filling opening for a rechargeable type extinguisher shall be no less than 19 mm 9 5 4 An extinguisher collar with external threads shall have sufficient height so that the cap or valve does no contact the dome or bottom with the gasket removed 31 BOS 252 2007 9 5 5 Acap valves or closure shall withstand the burst test pressure specified for the cylinder for 1 min without rupture For this test remove or plug pressure relief devices 9 5 6 The edges and surfaces of a fire exti
71. the tamper indicator is broken by the action needed to start discharge of the extinguisher or if an internal load is continuously applied to the release mechanism the force required to accomplish discharge or release of the internal load may exceed 70 N but shall not exceed 140 N 9 12 Requirements for pressure gauges and indicators for low pressure extinguishers 9 12 1 General 9 12 1 1 A rechargeable extinguisher of the stored pressure type except carbon dioxide employing a single chamber for both the extinguishing medium and the expellant gas shall be equipped with a pressure gauge to show the amount of pressure in the chamber regardless if the valve is opened or closed EXCEPTION The pressure gauge may be omitted on an extinguisher having a disposable non refillable sealed chamber if a device such as an indicator is used to verify that the extinguisher is charged with the correct quantity of expellant gas 9 12 1 2 The operable pressure range of the gauge shall reflect the operating temperature pressure relationship of the extinguisher See 7 1 9 12 1 9 The pressure gauge face shall indicate the appropriate units for which the gauge is calibrated such as kPa or bar or any combination of pressure units 9 12 1 4 The maximum indicated gauge pressure shall be between 150 and 250 of the indicated service pressure Ps at 20 C but no less than 120 of the maximum service pressure Pms The gauge dial shall indicate in green
72. tioned to its minimum storage temperature for 18 hours A flat metallic surface at least 750 mm wide having not more than a 2 mm deep layer of sodium bicarbonate powder placed on top of the surface is to be placed around the front and sides of the rectangular fire tray and completely around the round fire tray The liquid oil in the fire tray is to be heated by its heat source until a temperature of 175 C to 190 C is achieved Each conditioned extinguisher shall be discharged toward the fire tray within 5 minutes of it s conditioning with the nozzle held at the distance specified by the manufacturer and shown on the nameplate but not greater than 2 meters The distance is to be measured from the front edge of the tray to the nozzle The discharge effects are to be observed and evaluated in accordance with the requirements of paragraph 8 8 1 9 Construction requirements 9 1 High pressure extinguishers Extinguishers with a service pressure greater than 2 5 MPa 25 bar shall be fitted with a cylinder which is designed tested and marked according to national regulations 9 2 Low pressure extinguishers 9 21 General requirements 9 2 1 1 These requirements are applicable to extinguishers having a service pressure Ps not exceeding 2 5 MPa 25 bar 9 2 1 2 A portable extinguisher with a charge exceeding 3 kg shall be constructed so that it can be stood vertically without support 9 2 1 3 The manufacturer shall ensure that the welds show c
73. tmosphere Details of Class B test fires are given in Table 9 Each test fire is designated by a number followed by the letter B 8 4 3 Fuel Use an aliphatic hydrocarbon having an initial boiling point of no less than 88 C and a final boiling point of no more than 105 C NOTE Typical fuels meeting this requirement are heptane and certain solvent fractions sometimes referred to as commercial heptane Table 9 Dimensions of Class B test fires Classification Minimum Volume of Dimensions of test fire tray discharge of liquid extinguisher Diameter Internal Minimal Approximate depth thickness surface area of walls of fire S mm mm mm m 889 8 570 t 10 150 4 5 2 0 0 25 13B 19 720 t 10 150 4 95 2 0 0 41 21B 8 21 920 10 150 4 5 2 0 0 66 34B 8 34 1 170 10 150 45 2 5 1 07 55B 9 55 1 480 15 150 49 2 5 1 73 70B 9 70 1 670 15 150 5 2 5 2 20 89B 9 89 1 890 20 200 5 2 5 2 80 113B 12 113 2 130 20 200 5 2 5 8 55 144B 15 144 2 400 25 200 5 2 5 4 52 183B 15 183 2710 25 200 5 2 5 5 75 233B 15 233 3 000 30 200 5 2 5 7 32 NOTE Each test fire is designated by a number in a series in which each term is equal to the sum of the two preceding terms this series is equivalent to geometric progression having a common ratio of about 1 62 Test fires larger than those given may be constructed following the rules of this geometric progression The additional
74. to contain flames for 4 1000 12 to floor level gas heating to prevent piloted ignition Figure 8 General Dimensions for Class F Test Apparatus Type B Apparatus for Class 15F 25F and 75F 44
75. ts specified can be conducted Subject in general a part larger than 25 mm diameter to all tests For a circular cross section o ring smaller than 25 mm but larger than 12 5 mm omit the elongation test For a circular cross section o ring smaller than 12 5 mm omit the elongation and tensile strength tests For an o ring less than 25 mm in diameter with a generally square shaped cross section omit the tensile strength and elongation tests If the size of the part precludes accurate testing subject larger samples of similar parts made of the same compound to those tests omitted on the parts 9 15 2 Compression set 9 15 2 1 A sample of a rubber or rubber like part shall have a compression set no greater than 25 of its original thickness after being compressed by one third of its original thickness 9 15 1 2 Conduct the compression set test on button samples compressed by one third of their original thickness for 24 h at 20 C at the minimum operating storage and use temperature and at 55 C 10 Marking and colour 10 1 Colour The recommended colour for extinguisher bodies is red 10 2 Marking NOTE An example of the layout for marking is given in Figure 5 10 2 1 General 10 2 1 1 The operating recharging and inspection and maintenance instructions shall be in the form of an etched or embossed metal nameplate or band or an acceptable pressure sensitive nameplate attached to the side of the extinguisher body or in the form of silk scree
76. uld be made for a change of colour that occurs naturally due to the temperature changes It is recommended that two samples of the agent be stored in closed glass containers and one subjected to the same cycles as the extinguishers in order to establish a reference sample 7 7 Tapping test 7 7 1 Requirements Portable extinguishers shall comply with the following requirements after being subjected to the conditioning specified in 7 7 3 a shall operate satisfactorily b commence discharge within 5 s of the opening of the control valve 0 not retain more than the following percentage of initial charge within the extinguisher following complete discharge complete extinguisher discharge includes the medium and propellant 1 powder 15 96 2 allother media 10 7 7 2 Test apparatus Compaction machine designed to accept only one extinguisher at a time which shall be raised by a rod and guided by castors The plate supporting the extinguisher shall be steel 300 mm 5 mm square and 60 mm 1 mm thick Figure 1 is an example of an acceptable test apparatus Observe the following points a ensure that the rod is adjustable as to adjust to the extinguisher base b ensure that the rod can move freely in the guide castors the extinguisher shall also be guided without constraint BOS 252 2007 7 7 3 Test method An extinguisher in a normally charged condition shall be held in the vertical position and dropped vertically five
77. us during operation at 63 C 5 C 9 8 3 5 An acceptable alternate test is described in Method A of ISO 4892 2 using a Xenon arc source for a period of 500 h Use the following conditions 65 C 3 C black panel temperature 50 5 96 relative humidity spray cycle 102 min dry interval 18 min water spray 33 BOS 252 2007 total dose of exposure 1 GJ m 500 h at 550 W m 9 8 4 Impact resistance Mount at least four samples subjected to the ageing test see 9 8 2 2 two with and two without the safety locking device engaged and pressurize the extinguisher cylinder to the maximum service pressure Pms with nitrogen after being filled 95 with a water and anti freeze solution Test the samples at 20 C 3 C or at the minimum recommended operation temperature whichever is lower The test is carried out as described in 7 5 1 No hazardous changes shall occur to the valve assembly such as splinters fractures or cracks NOTE The valve shall then be capable of withstanding the test pressure Pt for 1 min without bursting 9 8 5 Normally non pressurized components Subject plastic extinguisher components which withstand pressure upon extinguisher operation to the burst air oven ageing and impact resistance tests The air oven exposure is either 100 C for 70 days or 87 C for 180 days at the manufacturer s choice External plastic components shall comply with the ultraviolet light test 9 8 6 Test for exposure to extinguishing

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