XL90 Series High-Performance Positioner - Flowserve

1 ACAIM009 (AC-96) 7/02 Page: 1 of 12 2002, Flowserve Corporation, Printed in USAXL90 Series High-Performance PositionerInstallation, Operation and Maintenance InstructionsAccord Controls765 South 100 East1978 Foreman Unit of Flowserve CorporationProvo, Utah 84606 Cookville, TN : 801 373 4576 Phone: 931 432 4021 CONTROLS GENERAL INFORMATIONThis bulletin is designed to assist in installing, calibrating,troubleshooting and performing maintenance as required for theXL90 Series High-Performance users and maintenance personnel should thoroughlyread and strictly follow the instructions contained in this bulletinprior to operating the Positioner .

2 Any questions concerning thisproduct should be directed to a Flowserve avoid possible injury to personnel or damage to valveparts, WARNING and CAUTION notes must be strictlyfollowed. Modifying this product, substituting non-factory parts or using maintenance procedures otherthan outlined could drastically affect performance and behazardous to personnel and xl90 High-Performance Positioner is a two-stage deviceand is designed for use in control loops where fast response isrequired. The xl90 Positioner is designed to be modular and usethe P/P module for 3-15 psi input signal or the NT 3000 SeriesTransducer Module for 4-20 mA input xl90 High-Performance Positioner is designed as a four-way device, but can easily be converted to a three-way device byplugging one of the output ports.

3 NOTE: The xl90 High-Performance Positioner must use theI/P NT 3000 Transducer. The I/P 2000 Transducer is notacceptable for use with the xl90 Series Positioner . The xl90 Positioner can handle supply pressures up to 150 psi;thus, a supply regulator is usually not required. However, a fivemicron air filter is required for pneumatic positioners and acoalescing filter is required for I/P : The air supply should conform to ISA Standard (adew point at least 18 F / -8 C below ambient temperature,particle size below 5 microns, oil content not to exceed onepart per million).

4 The xl90 Series Positioner features an adjustable gain of400-1100:1. The medium gain setting is standard for smalleractuators, while the high gain setting is used on larger actuators(refer to Gain Adjustment Procedure section for further details.) Positioner OPERATIONThe Positioner schematic (Figure 1) shows an xl90 Seriespositioner connected for double-acting service on a rotary rack-and-pinion actuator. Tension on the feedback spring providesfeedback to the Positioner , which varies as the stem positionchanges.

5 The spring-loading force is applied through the feed-back linkage and cam to the Positioner s input signal pressure is applied between the diaphragmsin the input capsule. Therefore, the input capsule serves as aforce-balance member, matching the valve stem position (asmeasured by tension on the feedback spring) to the the opposing forces balance exactly, the system will bein equilibrium and the stem will be in the exact position calledfor by the instrument signal. If the opposing forces are not inbalance, the input capsule will move up or down and, by meansof the pilot-valves, will change the output pressures, moving thestem until the tension on the feedback spring exactly opposesthe instrument signal Series high -PerformancePositionerPage.

6 2 of 12 ACAIM009 (AC-96) 7/02 2002, Flowserve Corporation, Printed in USAXL90 Series High-Performance PositionerInstallation, Operation and Maintenance InstructionsAccord Controls765 South 100 East1978 Foreman Unit of Flowserve CorporationProvo, Utah 84606 Cookville, TN : 801 373 4576 Phone: 931 432 4021 CONTROLS Figure 1: xl90 Positioner Schematic for Air-to-OpenFigure 2: Positioner Mounting with NAMUR shaftSupply SeatUpper PilotPoppetExhaust SeatPort No. 1 RestrictionSupplyPilot ValveCapsuleExhaust SeatPort No.

7 2 Lower PilotPoppetSupply SeatPistonCylinderBalance AdjustmentFeedback SpringZero AdjustmentRange AdjustScrewsCamFeedback(shaft)Instrument SignalUpper DiaphragmLower DiaphragmFlapperDetectingNozzleInput CapsuleThe sequence of operation is as follows: An increase in instru-ment signal pressure forces the input capsule of the capsule in turn moves the flapper awayfrom the detecting nozzle. This allows a larger flow rate throughthe nozzle, decreasing the pressure exerted on the top of thepilot valve air biases the pilot-valve in an upward direction.

8 Asthe capsule moves up, it will close the exhaust seat of the upperpilot poppet and open the supply seat, which applies increasedair pressure to the bottom cylinder port. At the same time, thepilot-valve capsule will open the exhaust seat for the lower pilotpoppet; thus, decreasing pressure to the top cylinder difference in pressure will drive the piston outward, rotatethe pinion and stretch the feedback spring until the spring ten-sion exactly opposes the force resulting from the instrument sig-nal pressure. At this point, the flapper will be moved toward thedetecting nozzle to restore the pressure above the pilot-valvecapsule to its equilibrium value.

9 As a force-balanced conditionis approached, the pilot-valve capsule will be forced back to aneutral position where the pilots are neither supplying air to, norexhausting air from, their respective sides of the decrease in instrument signal pressure reverses the describedactions and causes a proportional inward movement of actuatorpistons and a reversal in pinion (AC-96) 7/02 Page: 11 of 12 2002, Flowserve Corporation, Printed in USAXL90 Series High-Performance PositionerInstallation, Operation and Maintenance InstructionsAccord Controls765 South 100 East1978 Foreman Unit of Flowserve CorporationProvo, Utah 84606 Cookville, TN : 801 373 4576 Phone: 931 432 4021 CONTROLS ConduitInputTemp-ThreadPrefixModel IndicationGageseratureCamConnection Option Notes: 1.

10 Internal limit switches and an internal transmitter cannot be used When options F, J, K, M, or N are used with an I/P transducer, input model number 91 must be When option Q is used with an I/P transducer, input model numbers 90 or 92 must be Internal limit switches or an internal transmitter cannot be used in an explosion proof environment. As an alternative, the explosion proof UltraSwitch may be mounted ontop of the Positioner . (Use option T.) xl90 Part Numbering SystemPREFIXS electionCodeBlack EpoxyABWhite Food Grade EpoxyAWINPUT MODELS electionCodePneumatic Input 3-15 psi90 Electro-Pneumatic Input 4-20mA91 General Purpose NT3000 Electro-Pneumatic Input 4-20mA92FM/CSA Explosion Proof and Intrins.