Differential Pressure and Flow Meter Media 4K
Contents
1. 4 5 Exchanging the limit switch unit The limit switches can only be exchanged as acomplete switch unit To exchange the unit first unscrew the case cover then the cover plate with the type des ignation Remove the three mounting screws on the scale Incline the switch unit turn the pointer 10 and lift out the switch unit below the pointer Remove the dial plate and label Unscrew ter minal base on the rear cover Secure the terminal bracket of the new switch unit on the rear cover Secure the dial plate using a screw top cen ter Align the web of the zero shaft of the new switch unit in accordance with the slot in the shaft of the indicating mechanism Re position the red switch indicator com pletely to the right and left Then lightly place on the switch unit Turn the instrument pointer inclining the switch unit until it is situated below the pointer and can be screwed to the scale Attach the cover plate and screw tight Adjust zero and switch according to sections 4 1 and 4 4 5 Accessories The instruments are supplied without screw fittings The following items required must be separately purchased Compression type fittings drain or vent plugs and screw joints with orifice plates restric tions for damping oscillation caused by the measuring medium especially with gas measurements Qiy Designation Order number Normal Rinsed fo2. lt 0 03 1 bar Inductive limit switches Limit value pointer with inductive pick off min limit value distance 12 of the scale length Proximity switch SJ3 5NorSJ3 5SN Switching accuracy lt t2 8 lt t2 Reverse span approx lt 0 8 lt 0 6 Control circuit Values corresponding to the subsequent switching amplifier transistor relay Temperature range Permissible ambient temperature SJ 3 5 N 25 to 70 C SJ 3 5 SN 40 to 100 C Degree of protection IP 54 according to DIN 40 050 Approximate weight 3 5kg Materials Measuring Case heads Measuring and Diaphragm plates Lever Indicator case diaphragm and spring plate guide springs ECO Cu Zn 40 Pb WN 1 4310 WN 1 4571 WN 1 4310 Polycarbonate Special version measuring cell Housing and heads A 351 CF8M spring plate WN 1 4301 with stainless steel housing WARNING This differential pressure and flow meter may only be assembled commissioned and operated by experienced personnel familiar with such procedures Proper shipping and appropriate storage are always assumed Take appropriate measures to prevent any danger from occurring on the measuring apparatus caused by the flow or process medium or the system pressure 2 Installation 2 1 Arrangment of the instruments The basic arranging sequence of the instru ments is depicted in the following installation schematic Whether the
3. steam is to be measured In liquid measure ment they are needed only when the indicat ing unit is arranged at the point of measure ment When measuring gas they are required as separation tanks to cut off the condensate when the indicating unit is arranged below the point of measurement GW1 GW2 Transistor relay e g WE 77 Ex f Output Supply Fig 5 Terminals From the measuring point Blow out Fig 6 Valve blocks manifolds 3 Commissioning 3 1 For steam measurement The steam should never directly contact the working diaphragm of the instrument For this reason unscrew the differential pressure lines below the shut off valves or of the valve block and fill the instrument with water As an alternative method wait approxi mately 20 minutes after commissioning the plant steam switched on with blocked shut off and equalizing valves or valve block until condensate in the differential pressure lines rises above the valve up to the orifice plate Proceed first by opening the upstream line Then close the equalizing valve or the by pass of the valve block and open the down stream line Wait a short period of time then remove both vent plugs of the measu ring cell one after another until condensate escapes free of bubbles and firmly tighten screws again In the same manner vent the equalizing tanks Lig
4. izontal tubes Use a mounting component without a clamp for mounting to walls see dimensional drawing section 6 For panel mounting panel cut out 170 min 165 hole circle 180 mm Unscrew the case cover and secure the rear cover with measur ing cell to the panel using four countersunk screws M4 2 4 1 Electrical connection This procedure involves connecting the limit switches of the indicator to a control unit De pending on whether the version has one or two proximity switches control devices of PE PERLUND FUCHS are recommended For one switch WE 77 Ex1 For two switches WE 77 Ex2 Terminal connections are depicted in Fig 5 How the different limit switches function is shown in the table on page 10 2 5 Accessories 2 5 1 Shut off and equalizing valve It is good practice to install both a shut off valve and in addition an equalizing valve in the differential pressure lines A valve block manifold with three or five combined valves is available as an acces sory The valves are used to shut off both of the differential pressure lines and for short circuit switching on the indicating unit for checking zero Lines can be additionally con nected to valve blocks with five combined valves to blow out and flush through the measuring system Fig 6 shows how the valves are to be placed 2 5 2 Condensation chambers Condensation chambers for maintaining a constant liquid column are required when
5. tube Figs 4 1 4 2 The direction of flow must coincide with the attached arrow An undisturbed straight length of pipe is required at the inlet and out let side of the orifice plate assembly With the orifice tubes supplied by SAMSON these pipe lengths are ensured through the welded on calibrated pipes With orifice flanges the smooth length of pipe preceding the orifice plate is specified in the Confirma tion of Order The orifice plate assembly and also the seals must not be eccentrically displaced relative to the pipeline Never install control valves that continuously vary the operating state of the process medium upstream of the orifice plate assembly e g manually operated valves or temperature regulators controllers The operating state is expected to correspond to the calculated state as close as possible In contrast regulators which do not vary the operating state e g pressure regulators prove to be advantageous upstream of the measuring facility 2 3 Differential pressure lines Install the differential pressure lines with a pipe of 12 mm external diameter according to Fig 3 IMPORTANT Always arrange cor rectly as shown in Fig 6 The use of com pression type fittings Fig 5 will ensure tight sealing of the lines Pipe runs which in normal cases would be placed horizontally are to be installed with a slope of at least 1 20 sloping from the orifice plate or the point enabling ventilation Th
6. Differential Pressure and Flow Meter Media 4K Fig 1 Media AK with two limit switches Zero adjustment 14 an si w D 1 Design and principle of operation The Differential Pressure and Flow Meter Media 4K measures the differential pressure in industrial plants and domestic services When used as a differential pressure meter in with a combined orifice plate the instrument indicates the rate of flow flow meter When ever an adjustable limit value is reached contact making is achieved by means of proximity switches The indicating unit Media 4K essentially consists of a differential pressure measuring Edition April 1995 cell containing a measuring diaphragm and a measuring spring plus the indicating unit gauge comprising pointer mechanism and dial When used as a flow meter an orifice plate assembly primary element consisting of ori fice flange or orifice tube is necessary in ad dition to the indicating unit In addition different accessories must be used depending on the application Con densation chambers shut off valves or valve blocks shut off and equalizing valve Mounting and operating instructions EB 9518 E The differential pressure Ap p p2 or the pressure drop at the orifice plate produces a force on the measuring diaphragm 3 This force is balanced by the measuring spring 2 The deflection of the measuring dia phragm 3 and lever 7 which is
7. Fig 2 Functional diagram 1 Differential pressure measuring cell 2 Measuring spring 3 Measuring diaphragm 4 Disc 5 Measuring range plate 6 Guide springs 7 Lever 8 Feeler tracing role 9 _ Pointer mechanism 10 Pointer with carrier drive pin 11 Metal tag 11 1 Metal tag 12 Proximity switch 12 1 Proximity switch 13 Pointer of limit value 13 1 Pointer of limit value 1 1 Technical data Differential pressure meter With measuring diaphragm for measuring spans from 40 to 600 mbar 250 to 1600 mbar or 1600 to 2500 mbar Measuring span Max mbar Min 60 100 160 250 400 600 1000 1600 2500 40 60 100 160 250 400 600 1000 1600 Nominal pressure PN 40 unilaterally overloadable up to 40 bar Volumes within the measuring chamber Upstream high pressure chamber Approximately 80 cm downstream low pressure chamber Approximately 25 cm 3 Displacement volume Maximum 9 cm at smallest measuring span 5 cm Indication Scale 270 scale length approximately 300 mm Scale division Oto 100 linear or squared on request for any linear measuring quantities for quantities according to an equation curve or table Performance Indication linear to differential pressure Deviation of characteristic lt t2 5 lt 1 6 including hysteresis Sensitivity lt 0 5 lt 0 25 Influence in of the measuring span Static pressure
8. ND REGELTECHNIK Weism llerstra e 3 D 60314 Frankfurt am Main Postfach 10 19 01 D 60019 Frankfurt am Main Telefon 0 69 400 90 Telefax 0 69 400 95 07 EB 9518 E S C 04 95
9. amber Measuring range mbar Measuring spring Minimum Maximum Wire mm Length 40 1 mm Order number 0 to 40 Oto 60 1 2 34 4 1400 5871 1 01060 Oto 100 1 6 32 7 1400 5872 Diaphragm 0 4 52 Oto 100 Oto 160 1 8 32 2 1400 5873 Guide spring 0 5 Oto 160 Oto 250 2 25 32 1400 5874 Oto 250 0 to 400 2 5 31 9 1400 5875 0 to 400 0 to 600 2 8 31 7 1400 5876 Oto 250 0 to 400 2 25 32 4 1400 5879 2 0 to 400 0 to 600 2 5 32 2 1400 5880 Diaphragm 0 4 70 0 to 600 Oto 1000 3 31 8 1400 5881 Guide spring 0 8 Oto 1000 Oto 1600 3 4 31 6 1400 5882 3 Diaphragm 0 6 70 Oto 1600 Oto 2500 3 6 31 6 1400 5885 Guide spring 0 8 Part Designation Order number 18 Discs set of different thickness 1400 5653 19 O ring 22x2 ECO 8421 0080 Version A Order no 1089 0961 Version B Order no 1080 0962 Increasing actual value display Metal tag inside Decreasing actual value display Metal tag outside Increasing actual value display Metal tag outside Decreasing actual value display Metal tag inside Version C Order no 1089 0963 Version D Order no 1080 0960 Metal tags outside when switching point is reached Metal tags inside when switching point is reached Increasing actual val display Metal tag 1 inside 2 outside Decreasing actual val display Metal tag 2 inside 1 outside Increasing actual val display Metal tag 1 outside 2 insid
10. e Decreasing actual val display Metal tag 2 outside 1 inside Version E Order no 1089 0964 Version F Order no 1080 0965 Increasing actual value display Metal tags 1 a 2 inside Decreasing actual value display Metal tags 1 a 2 outside Increasing actual value display Metal tags 1 a 2 outside Decreasing actual value display Metal tags 1 a 2 inside Proximity switches with opening function NC Normally Closed Metal tag outside Switching signal on L signal of the proximity switch Contact closed or output activated Proximity switch highly resistive undamped Power consumption 23 mA Metal tag inside Switching signal off O signal of the proximity switches Contact opened or output disabled Proximity switch highly resistive damped Power consumption lt 1 mA 10 4 4 Switching function Adjusting the switches after connecting to the transistor relay section 2 4 1 Slide the switch indicator or the red switch indicators such that they point to the value at which contact making is desired on the dial For a finer adjustment test bench the measuring chamber is to be applied with pressure in order to check whether the con tact making occurs at the desired indicated value by the movement of the instrument pointer If necessary correct the position of the red switch pointer accordingly
11. e minimum bending radius must not fall below 50 mm Thoroughly flush through the differential pressure lines before connecting them to the instrument 2 4 Indicating unit Media 4K Compare the operating data to that of the orifice plate assembly in advance to assem bling Make certain that the upstream high pressure and the downstream low pressure lines are connected to the corre sponding inlet and outlet connections NOTE To connect the differential pressure lines compression type fittings are required In addition the unused open connections of the instrument must be provided with plugs or vent plugs depending on how the instru ments are to be arranged see also Acces sories in section 5 UPL Bu H rp ZN o Ar Inlet20t050xd__ __ Outlet 5 x D Fig 4 1 Orifice Flange Type 90 Fig 4 3 How the differen tial pressure lines are arran ged on the orifice plate as sembly primary element For gas Fig 4 2 Orifice Tube Type 91 For liquids For steam Carefully clean the process connections be fore connecting the differential pressure lines Never flush through the instrument with com pressed air or pressurized water At the place of installation secure the instru ment to the tube wall or mounting plate free of vibrations Use a mounting component with a clamp for attachment to vertical or hor
12. g to the desired final value of the measuring range to the upstream con nection of the measuring chamber Then dis place the feeler role 8 on the measuring range plate 5 upwards or downwards until the pointer 10 indicates the full scale value Remove the pressure pointer must return to zero again and correct zero using the ad juster 14 Fig 1 Apply the pressure corresponding to the final value of the measuring range to the measur ing chamber again and re adjust the feeler role again until the pointer indicates the final value If necessary repeat this adjustment proce dure until zero and the final value correspond to the desired measuring range 4 3 2 Modifying the measuring range by exchanging the measuring spring Fig 8 Adjust on the test bench only If the measuring range is to exceed that of the installed measuring spring select the measuring spring required according to the measuring range table Only the springs corresponding to the existing measuring chamber see nameplate can be exchanged For this purpose proceed as follows Unscrew the case cover and adjust zero using the corresponding screw 14 Fig 1 Remove the screws 15 and take out the measuring plate 16 guide plate 17 measuring spring 2 and disc s 18 at the downstream connection of the chamber The spring guide 20 remains in the case Install the new spring 2 and then secure the spring plate using two screws 15 Chec
13. g valve and in the last step slowly but gradually open the downstream line as far as possible The in strument is in operation again For applications with an installed valve block open the bypass of the valve block and close the upstream line open in reverse sequence 4 2 Draining When gases are measured now and then drain condensate from the separation tanks Close the valves in the differential pressure lines valve block prior to opening the drain plugs 4 3 Measuring span Measuring range The measuring span of the differential press ure and flow meter is determined by on one hand the measuring chamber three versions with different measuring diaphragm 3 and guide spring 6 and on the other hand the installed measuring spring 2 The versions of measuring diaphragm and guide spring are noted on the nameplate The instrument is pre adjusted ex factory to the range specified in the order and can only be subsequently modified in the range per mitted by installed measuring spring The measuring span can be continuously ad justed up to 60 of the maximum measuring span If another span is to be adjusted the measuring spring 2 must be exchanged See also nameplate on the instrument and the table referring to the measuring ranges 4 3 1 Adjusting and modifying the measur ing range Fig 7 For best results adjust on the test bench Unscrew the case cover and apply the press ure correspondin
14. htly tap the case of the indicator or the equalizing tanks to promote the escape of air Subsequently check zero as described in sec tion 4 1 and put the instrument into service again NOTE When installed reversibly measuring in strument above the point of measurement the differential pressure lines can partly drain when plantis relieved of pressure When re commissioning the measuring ar rangement must be vented so that it can fill with condensate again 3 2 For liquid measurement First open the upstream line by gradually turning Then close the equalizing valve or the bypass of the valve block and open the downstream line Remove the vent plug at the measuring cell until the air has escaped Then firmly tighten again Subsequently check zero at the measuring cell as described in section 4 1 and put the instrument into service again 4 Operation 4 1 Zero adjustment If the differential pressure lines are provided with shut off and equalizing valves zero can be checked even when the plant is being operated First close the downstream line of the shut off valve Then open the equalizing valve and close the upstream line of the shut off valve so that a balance of pressure is obtained in the instrument The pointer must indicate zero If it does not read zero re adjust the zero screw 14 Fig 1 until the zero position is reached To commission first open the upstream line Then close the equalizin
15. instrument is to be secured above or below the point of meas urement gauging point or whether equali zing tanks are to be installed depends on the type of process fluid and the local conditions Normal and reversed installation are shown in the installation schematic Normal installa tion is always to be preferred Only use rreversed installation when there is no other alternative especially when measuring steam Further details can be found in the publication VDE VDI 3512 Part 1 For measuring the liquid level according to the first schematic shown in the bottom left the additional height z must be included in the measurement Therefore keep it as small as possible The dimension K compensation height schematic 2 can be selected as large as desired in accordance with the installa tion conditions Liquids Measurement of Reversed Installation Normal Measuring range Measured height Additional height Compensation height ANTZ I Steam Normal Gases Reversed Normal A Separation tank Shut off valve Indicating unit Measurement on pressure vessels with condensated or non condensated pressure cushion Fig 3 Installation schematics Measurement on open vessels with measuring instrument on the bottom liquefied gases Measurement with cryogenic cold service installations 2 2 Orifice plate assembly dp pick up orifice flange or orifice
16. k zero Correct any deviation by insert ing discs 18 of different thickness order number see table For this purpose the spring plate must be unscrewed again each time When zero is reached firmly screw on the spring plate make certain that the O ring 19 is located at the correct position re place if necessary Adjust the measuring range according to sec tion 4 3 1 NOTE When modifying the measuring range corresponding to the differential pressure in the flow measurement be aware that flow indicator also will change Re calculation is required in this case The opening ratio of the orifice plate m d D must also be taken into account Note on instruments for oxygen O2 Equipment used for measuring oxygen is pro vided with an adhesive label Oxygen Keep free of oil and grease These versions are assembled by the manu facturer under special conditions and sub sequently flushed Always wear suitable working gloves when exchanging parts which can come into con tact with oxygen e g measuring springs 2 Measuring spring 5 Measuring range plate 8 Feeler tracing role 15 Screws 16 Spring plate 17 Guide plate 18 Discs 19 O ring 20 Guide spring Fig 7 Adjusting the measuring range Decr measu ring range Incr measu ring range 1517 18 20 Fig 8 Exchanging the measuring Measuring ch
17. propor tional to the differential pressure is led out of the pressure chamber by way of a flexible disc 4 and is transmitted to the pointer mechanism 9 via the measuring range plate 5 and the adjustable feeler role 8 By means of the zero adjuster 14 Fig 1 the pointer can be adjusted in accordance with the scale value The scale indication is linear for the differen tial pressure and quadratic squared for the rate of flow due to the relationship between the rate of flow Q and pressure drop p in the equation Q K Ap Limit switches The limit switch unit is actuated when the met al tags 11 and 11 1 enter the pick up field of the proximity switches 12 and 12 1 of the limit value pointers 13 and 13 1 Move ment is via the pointer shaft IF the metal tag enters the pick up field of the associated proximity switch the switch becomes highly resistive If the tag leaves the field the proximity switch becomes low resis tive This function corresponds analogous to that of a mechanical type switching contact Whenever the limit value is exceeded in either direction the carrier moves the metal tag out of the proximity switch Thus the corresponding contact switches the control circuit via the subsequent switching amplifier transistor relay Connection Connection e 1 6 A VA 5 raa PH bh i 7 3 4 5
18. r O2 2 Screw joints for tube 1 2 steel 1400 5842 1400 5843 2 Screw joints for tube 012 stainless steel 1400 5844 1400 5845 2 Screw joints for tube 10 steel 1400 5846 1400 5847 2 Screw joints for tube 28 steel 1400 5860 1400 5861 2 Screw joints for tube 12 with orifice restrictor steel 1400 5848 1400 5849 2 Screw joints for tube 28 with orifice restrictor steel 1400 5850 1400 5851 2 Screw joints for tube 26 with orifice restrictor steel 1400 5852 1400 5853 2 Vent plugs brass with gaskets 1400 5654 1400 5658 2 Drain plug brass with gaskets 1400 5655 1400 5659 1 Drain plug half set brass with O ring 1400 5662 1400 5663 4 O rings 1400 5660 1400 5661 1 Mounting component for tube mounting 1400 5656 6 Dimensions in mm Tube mounting with mounting component Connection M8 Connection 31 L499 ey ar DR Me Bl kudet 0873 190 65 me 110 In 247 Wall mounting Se Panel mounting 8165 Mounting component Screw M5 Panel cukout pow lsse8 E cage l LOON BIO N BER N oe Li f Tr il od H Te Sa O zo s Optional LR j 5 i 84 5 Sy choe N 7 Counter vs N ef sunk screw M4 DIN 863 l gt s 14 2190 SAMSON AG MESS U
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