1. ABOUT THE PRODUCT:
Contents
1. need extended lever soso 9 Gauge 5 Y 1 4 NPT x O A m a of S qui d 5 2 js i es X E 7 1 4 NPT Dimension B for small actuatros 50 65 mm AND for large actuators 90 120 mm USER S MANUAL 83 f M2 4 e m m 10 ex 1 MOUNTING CONTROL ACTION INCREASING INCREASIING INCREASING DECREASING MOUNTING CONTROL ACTION OF JAL T JJ FORBES MARSHALL FIG e 4 i X uu BT MANI USER S FORBES MARSHALL Pressure Controller Part List USER S MANUAL 85 FORBES MARSHALL d Commissioning The Product Ref Fig G On start up the required air supply is adjusted at the AFR The supply pressure should be about 0 5 bar higher than the maximum Operating pressure of the connected control actuator See nameplate CONTROL RANGE The air is checked for moisture dirt etc by operating the drain valve The set point spring 30 is relieved by turning the nut anti clockwise direction The operating pressure Y now increases up to ma2. 5 10 5 10 50 100 500 1000 J 400 0 01 005 01 e bar 015 1 0 5 10 50 100 500 1000 The tabuler nates the range of set point according the numbered spring diameter Propartional band 1 w o feed back proportional band 1 adjusttable on feed back spring 1 measured on nozzle dia 3mm nozzle dia 2mm approx 60 tombac bronce 55316 bellows Max allow pressure FIG B USER S MANUAL 77 FORBES MARSHALL b Specifications Measuring Range Absolute Pressure Vacuum Supply Air Pressure Control Pressure Set Point Actual Value Speed Of Response Range Reversal Range Point Hysterisis Range Dependence On Supply Pressure Air Consumption Valve Speed 0 02 To 400 Bar 0 05 To 3 Bar 0 1 Bar Low Pressure 1 4 Bar 0 2 1 Bar See Fig No B 0 0296 Of Medium Set Point 0 033976 Of Medium Set 1 196 Of Medium Set Point 0 496 Per 0 1 Bar 300 NL hr On Y 0 6 Z 1 4 Nozzle Dia 0 2 40 Sec Up 5 Sec Down Nozzle 2 Actuator Ul 30 140 Sec Up 20 Sec Down Nozzle 2 Actuator UIII 60 78 USER S MANUAL FORBES MARSHALL 79 DIUM M FIG A USER S MANUAL FORBES MARSHALL Operation Ref Fig The pressure to be controlled x which is acting on the measuring unit bellows diaphragm etc is compared to a set point spring w Any
3. on the VDS The set pressure and the action of Roboter are given on it Suppose the action is reverse acting down stream control and set pressure is 4 5 bar Also check spring and bellow size as per the VDS Remove the cover 6 by unscrewing the M5x10L screws 2 4 nos Take out the ball bearing 32 hex nut 31 set point spring 30 Polish the flapper 25 with smooth polish paper and needle file and hit the contact screw 29 by soft headed mallet hammer to make the nozzle 9 impression on flapper 25 Check for impression If not there on the flapper r then repeat above steps Give air supply to AFR Adjust the pressure of the air between 3 3 5 bar Rotate the hex nut 31 in clockwise direction so that the valve opens fully i e 30 mm for given valve Check the pipeline for air leakage by spraying soap solution near all the joints There must not be any leakage Rotate the hex nut 31 in anti clockwise direction until the valve is 50 open i e 15mm Check the double arm lever to be horizontal If not then by rotating the adjustment lever make the double arm lever horizontal Rotate the contact screw 29 making it touch the bellow 44 Again rotate it 1 1 5 mm rotation of contact screw Now the valve should be completely close If not the Roboter is to be replaced completely Apply set pressure 4 5 bar through siphon If siphon is not used then bellow might get burst To check the bellow chamber is completely
4. FORBES MARSHALL 1 ABOUT THE PRODUCT a General Description This Valve Mounted pressure controller is a yet solid one for direct mounting to the control valve and direct impulse connection for various pressures including vacuum and absolute pressures It has the following outstanding characteristics 1 Separate interchangeable measuring units 2 In built supply air restrictor and output damping throttle 3 Reversal of action without additional parts USER S MANUAL 76 FORBES MARSHALL i to J 00 200 08 i 00 200 02 Bellows dial5 50 7 Bellows cia60 vacuum and ND 100 MAX 2 5 low pressure RulZe BSP E S B BSP 158 70 00 200 01 UD eU0 01 Al En 00 800 01 Diaphragm 060 a B 7 Low pressure ND4 2 160 R 3 8 BSP R 1 4 BSP 95 2 3 a8 00 800 19 204 lt SN 73 oS Bourdon tube lah pressure A B High pressure R 174 NP T 25 92 4 R 1 4 BSP 2100 Set point range 0 01 0 05 041 0
5. arating vessel as to avoid delays in pressure transmission The separating vessel should be mounted as near as possible to the tapping point 81 USER S MANUAL FORBES MARSHALL b Mounting Instruction For Pressure Controller Before connecting the air supply to the air filter and regulator the newly laid airline should be carefully blown out to line and it should be examined for any possible leakages ra 5 DIRECT CONTROL FUCTION REVERSE CONTROL FUCTION INCREASING PROCESS VALVE INCREASING PROCESS VALVE INCREASING OUTPUT DECREASING OUTPUT FEEDBACK WITH is FEEDBACK WITH 1 ARM LEVER 2 RAM 1LEVER SHAFT GRE FIG E USER S MANUAL FORBES MARSHALL ACTUATOR VALVE Hole No Hole No LIFT stroke 1 ar lever 2 lever 20 mm B 7 50 mm B 2 B 5 60 m B 6 B 5 100 mm B 8 B 8 Lift 100 mm
6. arranged as showing Fig numbers a amp b The lines have to be arranged with a slope of 1 10 so that the enclosed air bubbles can go up to the de aeration points Before start up the impulse lines controller and separating vessel should be carefully filled with a separating liquid e g Barium Chloride or Glycerin It has to be observed that the least possible air enters into the system Then the valve is to be carefully opened The media exerts pressure on the separating liquid in the separating vessel and the system is once more de aerated This is very important as the air bubbles rise in the measuring system and cause oscillation Q1 How to change springs and bellows Remove the cover 6 by unscrewing the M5x10L screws 2 4 noose Unscrew the hex nut 33 Take out the bearing 32 Take out the spring 30 and spring plate attached to it 28 Turn the notches using Plyer ensure that the notches are not damaged Now take out the spring and replace with new For bellow 3 5 remove the cover 6 by unscrewing the M5x10L screws 2 4 nos Unscrew the Allen bolt M8x35 20 4nos Remove the bellow chamber assembly 37 Replace bellow with new one Fix the new bellow by tightening Allen bolt M8x35 20 90 USER S MANUAL FORBES MARSHALL Q2 How to adjust Roboter settings for given valve lift Check what is the set pressure of valve check the action of Roboter Suppose the valve is 80 150 Observe
7. deviation in x alters the valve diaphragm pressure y at the nozzle altering the flow to the actuator and thereby the lift This alteration in lift is fed back to the controller via the adjustable spring R USER S MANUAL 2 FORBES MARSHALL GETTING STARTED a Installation The pressure control valve should be stored in its original packing until it is mounted The storage area must be dry and clean After mounting the valve should be supplied with control air this is best protection against fouling and corrosion The protection caps of the valve openings of the filter and regulating valve and of the pressure controller have to be taken off If there are conservatives in the spindle area of the valve they have to be removed carefully The diaphragm control valve is mounted vertically standing up with actuator on top The mounting place has to be easily accessible Maximum allowable temperature is 80 degrees centigrade The impulse connection is taken at about 1 2 m after the control valve The point of pressure taking has to be provided with a stop valve so that in case of troubles you can get the measuring system free of pressure Pressure tapping from a vertical line where the point of tapping is above the measuring chamber is ideal In this case the measuring line can remain filed and the possibility of air inclusion cam be eliminated With viscous media the tapping point has to be provided with a sep
8. filled observe the flowing medium coming out at the air vent port Now tight the air vent screw 39 Rotate the hex nut 33 up to 50 Yo opening of the valve Increase the set pressure 4 5 bar till the valve is fully closed Ensure output pressure p1 on the gauge 13 to 91 USER S MANUAL Q3 FORBES MARSHALL be zero or less than operating control range of valve Note that pressure Then decrease the pressure p2 bellow 4 5 bar Do it until the valve gets open fully Apply set pressure 4 5 bar and ensure the valve is 50 open To check smooth operation of the valve we should check the proportionate band P1 p2 set pr X 100 this formula should give result between 10 to 40 How to change the nozzle Remove the cover 6 by unscrewing the M5x10L screws 2 4 nos Unscrew the hex nut 33 Take out the bearing 32 Take out the spring 30 and spring plate attached to it 28 Remove the flapper lever 26 Unscrew the m4x40 screw 2nos 7 Take out the traverse 12 and traverse head assembly 8 Unscrew the nozzle 9 and replace with news Assemble in reverse as above steps Recalibrate 92 USER S MANUAL
9. of the below 35 and the thrust bolt 29 Depending on the impulse pressure X at the bellow 35 the distance between nozzle and flapper is changed and thereby the control pressure Y Referring to Fig H when impulse pressure increases the lever moves upwards nozzle closes control pressure increases and valve closes On decreasing impulse pressure X the lever moves down nozzle opens control pressure decreases and valve opens The set value of the spring W can be adjusted by a nut 33 by tightening amp releasing the spring tension 30 On the cover this tightening or loosening is marked as or respectively If set 88 USER S MANUAL FORBES MARSHALL point spring is tightened control pressure Y decreases set value W increases If set point spring is loosened control pressure increases set value W decreases The air supply is limited to a fixed value by the constant fixed throttle 18 so that it opens nozzle the pressure goes towards zero and the actuator can assume the fail safe position as determined by the spring In the given fig The Actuator is mounted in air to close position At the outer end of the lever 26 an adjustable feedback spring 21 is connected By blocking some spring threads the feedback force can be changed depending on the lift position of the control valve If the feedback spring is tightened the proportional range is widened and the control loop Is attenuated If the feedback spring i
10. ontrol valve closes and reduces the pressure Air is supplied at pressure Z which is to be free from dust oil and water of at least 4 Bar The supply pr to Roboter Z1 is adjusted on the Air Filter Regulator 1 The supply air reaches the nozzle flapper system through the constant restrictor 18 The flapper 25 at the nozzle lever 26 covers the nozzle 9 more or less depending upon the pressure deviation at the bellows 35 This in turn changes the control pressure y supplied to the actuator The air supply is limited to a fixed value by the fixed throttle 18 so that with open nozzle the pressure goes towards zero and the actuator can assume the fail safe position as determined by the spring In the given fig Actuator is mounted in air to close position At the outer end of the lever 26 an adjustable feedback spring 21 is connected By blocking some spring threads the feedback force can be changed depending on the lift position of the control valve If the feedback spring is tightened the proportional range is widened and the control loop is attenuated If the feedback spring is loosened the proportional range is shortened and the control loop reacts more sensitively and may even tend to vibrate The output signal y can be dampened by a damping throttle 16 The set point spring 30 secures the lever 26 in its bearing and counteracts the force on the impulse pressure X at the measuring system The bellows assembly consists
11. s loosened the proportional range is shortened and the control loop reacts more sensitively and may even tend to vibrate The output signal V can be dampened by a damping throttle 16 2 2 The set point spring 30 secures the lever 26 in its bearing and counteracts the force on the impulse pressure X at the measuring system The bellow assembly consists of the bellow 35 and the thrust bolt 29 Depending on the impulse pressure X at the bellow 35 the distance between nozzle and flapper is changed and thereby the control pressure V Referring to Fig No 1 when impulse pressure increases the lever upward nozzle opens control pressure decreases and valve opens The set value of the spring W can be adjusted by a nut 33 by tightening or releasing the spring tension 3 0 On the cover this tightening amp loosening is marked as respectively If set point spring is tightened control pressure y decreases set value W increases If set point spring is loosened control pressure increases set value W decreases 89 USER S MANUAL FORBES MARSHALL 4 TROUBLE SHOOTING In case there is trouble in starting the valve can be operated in any position by means of the hand wheel It is to be noted that after manual operation the hand wheel should always be set back into end position and locked by means of a lock pin In case of Viscous media the application of a separating vessel is necessary the installation should be
12. ximum value and control valve closes The Control Valve can now be started as follows Open the impulse valve slowly de aerating the measuring chamber Tighten slowly the Set point spring until the valve begins to open Set the spring tension to the desired set pressure If controller oscillates the measuring chamber must be de aerated again If this does not improve the situation the proportional range has to be enlarged by feedback spring 21 If the controller remains unsteady screwing in the damping throttle can damp the control pressure Y to the Diaphragm chamber 16 After start up the following service has to be done Examine if hand wheel is in end position and secured by lock pin Slightly tighten stuffing box nut to avoid leakage of media Tighten all nuts on valve 86 USER S MANUAL FORBES MARSHALL a 4 33 M roa Za A de 25 26 7 UE X AGEN 29 ee z FIG H 33 yW fe Edsa 2 16 BO I 2x 3 S 2 26 ge dg B 29 18 x Lem FIG I USER S MANUAL 87 FORBES MARSHALL 3 OPERATION AND MAINTENANCE a Basic Functions PRESSURE REDUCING CONTROLLER The FM valve pressure reducing controller works as a pressure reducing valve If the set pressure value is surpassed the c
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