Valtek Flow Boosters.pdf - PRO-QUIP

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Bypass Valve O-ring(Item No. 14)Bypass Valve(Item No. 9)Bypass Valve Nut(Item No. 13)Upper Spring Cap(Item No. 18)Input Signal PortHousing Bolt(Item No. 12)Housing Cover(Item No. 2)Upper Spring(Item No. 17)Upper Diaphragm(Item No. 8)Vent Ring(Item No. 3)Poppet(Item No. 4)End Plug O-ring(Item No. 15)SupplyOutputHousing(Item No. 1)Lower DiaphragmAssembly(Item No. 7)End Plug(Item No. 10)E0114Lower Spring Cap(Item No. 21)Lower Spring(Item No. 11)Figure 1: Flow BoosterNOTE: Item numbers correspond directly to the booster's bill of materials; refer to it for specific numbers.to prevent leaks. All piping and connection adaptersshould be rated at least as high as the maximum ratedbooster pressure, 150 psi (10.3 Bar). The flow boosteris designed to function properly in any position. Figures2 and 3 show possible installation configurations for twotypes of actuators.The supply air to the flow booster does not requireregulation if the maximum rated pressure of the actuatoror the flow booster, 150 psig (10.3 Bar), is notexceeded. All air flowing into the flow booster should bedry and filtered to ensure a clean and non-corrosivemedium.WARNING: The exhaust ports on the flow boosterexhaust air at extremely high velocities. Harm toindividuals or equipment can result if positionedtoo closely to the exhaust ports.After the flow booster has been installed, it may need tobe adjusted for optimal performance. Refer to “AdjustingFlow Booster Operation” section to make theseadjustments correctly.Adjusting Flow Booster OperationOnce the flow booster is mounted properly, the bypassvalve may need to be adjusted for proper operation.This should be done prior to making any positionercalibrations. To make this adjustment, refer to Figure 1,and proceed as follows:1. Turn the bypass valve counter-clockwise three orfour turns from its closed position.2. Calibrate the positioner according to positionerinstructions.3. Turn the bypass valve clockwise until the flowbooster actuates with large positioner inputchanges but does not actuate with small positionerinput changes. This is done by stroking the controlvalve and adjusting the bypass valve slightly untilthe desired dynamics is acheived. Turning thebypass valve clockwise increases booster actionand overshoot.34-2
CAUTION: Cycling the control valve can disruptthe process. Care must be used to ensurethis disruption will not adversely affect theprocess.4. Once the bypass valve has been optimally set,the bypass valve nut should be tightened downto prevent the bypass valve from turning duringoperation.NOTE: The flow booster is bench calibrated andmay need to be re-adjusted once the valve is in theprocess.NOTE: When two or more flow boosters are usedon one actuator, all bypass valves on one side ofthe actuator can usually be set the same.NOTE: If the control valve is used for only on-offoperation, the bypass valve should be turnedclockwise until it is nearly closed to maximizestroking speed.MAINTENANCEAlthough the flow booster is designed to provide a longservice life, periodic maintenance is required to extendthe booster's life. Some parts in the flow booster mayneed to be replaced periodically. These parts mayinclude: diaphragms, poppet valve, O-rings andsprings. If the lower diaphragm needs replaced, theentire lower diaphragm assembly (Item No. 7) must beordered.WARNING: Before performing any maintenance onthe flow booster, shut off the air pressure to thesupply line and the input signal line and slowlyrelease any internal pressure in the actuator andbooster. High pressures not released from thebooster supply lines may cause personal injury ordamage to the flow booster.WARNING: Shutting off the air supply to the positionerand hence control valve can cause the valveto move to its fail position or be disabled, causingexcessive pressures to build up in the system.This, in turn, may result in the system failing, causinginjury to equipment or personnel.Replacing The Diaphragm AssemblyTo replace the diaphragms, refer to Figures 1 and 4,and proceed as follows:1. With the flow booster in an upright position,unscrew the six cap screws. Lift the cover off theupper diaphragm. (If the cover adheres to thediaphragm, gently tap the cover loose with a rubbermallet under the bypass valve protrusion.)2. Remove the upper diaphragm and inspect fordamage or wear. If necessary, replace the upperdiaphragm.3. Remove the lower diaphragm assembly and inspectfor damage or wear. Particular attentionshould be given to where the bottom diaphragmcontacts the housing limit stops. Also, inspect theretaining rings for tightness of fit. If necessary,replace this assembly.4. Reinstall the lower diaphragm assembly.NOTE: Clean the diaphragm mating surfacesthoroughly before replacing the diaphragms.5. The poppet must be centered in the housing. Thisis ensured by pressing down on the lower diaphragmassembly slightly and then releasing pressurewhile holding the lower diaphragm assemblycentered. This procedure may need to be repeatedto center the poppet in the housing.Be certain the lower diaphragm assembly is centeredon the housing and the bypass hole anddiaphragm bolt holes line up with the appropriatehousing holes.NOTE: The lower diaphragm assembly and housinghave the same outside diameter dimension andshould be flush when installed correctly.6. Reinstall the vent ring, aligning it with the appropriatehousing holes.7. The distance between the lower poppet seat lineand the upper poppet seat line is important tobooster performance. To check this distance,place a straight edge across the middle of the ventring. The aluminum seat should be on the sameplane, within ±.030 inch (±762 mm), with the ventring. If it is not, the poppet may not be centered(see step 5), or it may be worn (see “Replacing thePoppet Valve” section).8. Reinstall the upper diaphragm and apply an antiseizelubricant inside the cover spring bore.9. Place the cap and spring on the center of thediaphragm, and replace the cover on the diaphragm(be certain spring cap slides into the bore).CAUTION: To ensure proper flow booster operation,be certain the bypass hole in the diaphragmsorients properly with the bypassholes in the housing, vent and cover.10. Replace the six housing cap screws and tightenthem finger tight. Be certain that the housing, ventand cover are concentric with each other beforetightening the bolts with a wrench in a crisscrosspattern.CAUTION: Care should be taken to not overtightenthe housing cap screws. Over-tighteningmay damage the diaphragms, preventingthe booster from operating properly.34-3
Page 1: Valtek Flow BoostersGENERAL INFORMA
Page 5 and 6: Flow BoosterOutput 2(plugged)Output
Page 7: Flow Booster TroubleshootingProblem

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