Flowserve XL90 User Manual

Flow Control

Installation, Operation, Maintenance Instructions

XL90 Series

High-Performance

Positioner

GENERAL INFORMATION

This bulletin is designed to assist in installing, calibrating, troubleshooting and performing maintenance as required for the XL90 Series high-performance positioner.

Product users and maintenance personnel should thoroughly read and strictly follow the instructions contained in this bulletin prior to operating the positioner. Any questions concerning this product should be directed to a Flowserve representative.

To avoid possible injury to personnel or damage to valve parts, WARNING and CAUTION notes must be strictly followed. Modifying this product, substituting nonfactory parts or using maintenance procedures other than outlined could drastically affect performance and be hazardous to personnel and equipment.

The XL90 high-performance positioner is a two-stage device and is designed for use in control loops where fast response is required. The XL90 positioner is designed to be modular and use the P/P module for 3-15 psi input signal or the NT 3000 Series Transducer Module for 4-20 mA input signal.

The XL90 high-performance positioner is designed as a fourway device, but can easily be converted to a three-way device by plugging one of the output ports.

NOTE: The XL90 high-performance positioner must use the I/P NT 3000 Transducer. The I/P 2000 Transducer is not acceptable 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 five micron air filter is required for pneumatic positioners and a coalescing filter is required for I/P positioners.

NOTE: The air supply should conform to ISA Standard S7.3 (a dew point at least 18° F / -8° C below ambient temperature,

particle size below 5 microns, oil content not to exceed one part per million).

The XL90 Series positioner features an adjustable gain of 400-1100:1. The medium gain setting is standard for smaller actuators, while the high gain setting is used on larger actuators (refer to ‘Gain Adjustment Procedure’ section for further details.)

POSITIONER OPERATION

The positioner schematic (Figure 1) shows an XL90 Series positioner connected for double-acting service on a rotary rack- and-pinion actuator. Tension on the feedback spring provides feedback to the positioner, which varies as the stem position changes. The spring-loading force is applied through the feedback linkage and cam to the positioner’s input capsule.

Instrument signal pressure is applied between the diaphragms in the input capsule. Therefore, the input capsule serves as a forcebalance member, matching the valve stem position (as measured by tension on the feedback spring) to the instrument signal.

When the opposing forces balance exactly, the system will be in equilibrium and the stem will be in the exact position called for by the instrument signal. If the opposing forces are not in balance, the input capsule will move up or down and, by means of the pilot-valves, will change the output pressures, moving the stem until the tension on the feedback spring exactly opposes the instrument signal pressure.

The sequence of operation is as follows: An increase in instrument signal pressure forces the input capsule downward. Displacement of the capsule in turn moves the flapper away from the detecting nozzle. This allows a larger flow rate through the nozzle, decreasing the pressure exerted on the top of the pilot valve capsule.

VLAIM 048-00 (181157.000.000) Flowserve Corporation, Valtek Control Products, Tel. USA 801 489 8611

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	Balance Adjustment	Feedback Spring	Zero Adjustment
Supply Seat			Range Adjust
Upper Pilot			Screws
Poppet			Piston
Exhaust Seat			Cylinder
Port No. 1			Cam
Restriction
Supply
Pilot Valve			Feedback
Capsule			(shaft)
Exhaust Seat			Instrument Signal
Port No. 2		Detecting	Upper Diaphragm
Lower Pilot		Nozzle	Lower Diaphragm
Poppet	Flapper	Input Capsule
Supply Seat

Figure 1: XL90 Positioner Schematic for Air-to-Open

Supply air biases the pilot-valve in an upward direction. As the capsule moves up, it will close the exhaust seat of the upper pilot poppet and open the supply seat, which applies increased air pressure to the bottom cylinder port. At the same time, the pilot-valve capsule will open the exhaust seat for the lower pilot poppet; thus, decreasing pressure to the top cylinder port.

This difference in pressure will drive the piston outward, rotate the pinion and stretch the feedback spring until the spring tension exactly opposes the force resulting from the instrument signal pressure. At this point, the flapper will be moved toward the detecting nozzle to restore the pressure above the pilot-valve capsule to its equilibrium value. As a force-balanced condition is approached, the pilot-valve capsule will be forced back to a neutral position where the pilots are neither supplying air to, nor exhausting air from, their respective sides of the piston.

A decrease in instrument signal pressure reverses the described actions and causes a proportional inward movement of actuator pistons and a reversal in pinion direction.

Installation of XL90 Series Positioner on Actuators

The XL90 can be installed on most sizes of rotary and linear actuators. Actuators can be either double acting or spring return. Cams can be used for direct acting or reverse acting directions. These instructions apply to rotary actuators only. For linear actuator mounting instructions, consult the factory.

NOTE: For retrofitting to an actuator equipped with an Apex positioner, the same bracket and bolting may be used.

NOTE: NAMUR mounting is available with the XL90 positioner. When retrofitting the XL90 positioner to an actuator equipped with another positioner, remove the existing positioner, tubing and associated bolting. See tubing instructions in Connecting XL90 Positioner Ports section.

Figure 2: Positioner Mounting with NAMUR shaft

Figure 3: Positioner Mounting with Double D Shaft and Linkage

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Mounting Instructions for XL90 with NAMUR Shaft Connection

1.Mount the bracket to the actuator. Finger tighten the bracket bolting.

2.If required, install a coupler on the actuator shaft. Make sure the shaft and coupler are centered. See Figure 2.

3.Verify the orientation of the actuator and coupler flats match the positioner flats on the end of the shaft. Loosen the cam if necessary. (See “Cam Installations” instructions.)

4.Install the positioner onto the bracket. Make sure positioner shaft and coupler are engaged and centered. Finger tighten positioner bolts.

5.Proceed to “Connecting XL90 Positioner Ports.”

Mounting Instructions for XL90 Positioner on Sereg Rotary Actuators

1.Mount the positioner to the transfer case plate in the proper orientation. Tighten the four bolts.

2.Loosen jam nut (see “Cam Installation” instructions).

3.Mount the follower arm, lockwasher and nut on the end of the shaft and tighten nut. Carefully hold the shaft with wrench on shaft flats.

4.With valve in closed position, make sure follower pin lever is mounted parallel to valve lever, flush with end of valve shaft and the nut is tight.

5.Place follower pin (mounted to the lever that is mounted to the valve shaft) into follower arm slot and bolt the transfer case plate in place finger tight only. See Figure 3.

6.Orient the cam to align the “L” shaped line located on the left side of the characteristic curve through the middle of the span arm roller. (See Figure 5.) The valve should be seated when this alignment is done. (See “Cam Installation” instructions.) For correct cam characteristics, see Table I.

7.Proceed to “Connecting XL90 Positioner Ports” instructions.

Connecting XL90 Positioner Ports

1.For double acting actuators, connect positioner ports 1 and 2 to the actuator. Port 1 is always connected to the actuator port used to drive the actuator away from its start or fail position (the factory cam setting is full clockwise at minimum input signal).

NOTE: For single acting, spring return actuators, plug output port 2.

2.Connect supply air to the port marked “SUPPLY.”

3.Connect air (for pressure inputs) or instrument tubing or wiring (for 4-20 mA inputs). For current inputs, the terminal is marked (+) and (-) inside the I/P module. The I/P is factory calibrated and should not require adjustment. If adjustments are necessary, see “Calibrating I/P Module Zero and Span Settings” section.

CAUTION: Signal air pressure higher than 30 psi may damage the module gauge and instrument signal capsule; a 3-15 psi instrument signal is recommended on the pneumatic module.

4.Stroke actuator/valve two or three times to align positioner, coupler and actuator. With 50% input (actuator/valve at 45 degrees), tighten all mounting bolts. Stroke actuator/valve again to verify there is no misalignment throughout the stroke.

5.Calibrate valve and adjust cam if necessary. (See “Cam Installation” and “Positioner Calibration” instructions.)

Cam Removal: Disconnect cam return spring. With a wrench carefully placed on the output shaft (if necessary), loosen and remove the jam nut. Remove pressure from the span arm by pushing it away from the cam. Remove the cam.

Cam Installation:

1.A) For NAMUR shaft end connections make sure shaft is properly aligned with coupler or actuator.

B)For Sereg actuators, make sure follower pin is in follower arm groove.

2.Push span arm away from shaft to avoid pressure on the cam.

Table I: Cam Characteristic Identification Sereg

Cam Guide

Sereg Actuator

NR

NX

NL

Plug Characteristic

MaxFlo Linear

Linear

Equal Percent

Linear

Equal Percent

Fail Position

Close

Open

Close

Open

Close

Open

Close

Open

Close

Open

Direct Acting

Linear

A

B

N

M

A

B

Positioner

Equal %

C

E

Q

P

N

M

C

E

A

B

Equal % Mod

B

A

Reverse Acting

Linear

B

A

M

N

B

A

Positioner

Equal %

E

C

P

Q

M

N

E

C

B

A

Equal % Mod

A

B

Flowserve Corporation, Valtek Control Products, Tel. USA 801 489 8611

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Figure 4: Alignment for Accord Cams

3.Place cam over the shaft with the appropriate characteristic facing up and closest to the span arm roller. For Sereg cams, see Table I. For Accord cams, “D” represents directacting and “R” represents reverse acting.

4.A) For NAMUR shaft end connections, make sure the round mark on the left hand side of the characteristic curve is lined up with the span arm roller bearing. See Figure 4.

B) For Sereg actuators, make sure the line on the left hand side of the characteristic curve is lined up through the middle of the span arm roller bearing. See Figure 5.

5.Tighten jam nut making sure cam does not rotate. Use a flat screwdriver to prevent cam rotation and shaft flats to prevent shaft rotation (if necessary).

6.Connect supply pressure to port marked ‘Supply.’

7.Stroke actuator/valve two or three times to align position with actuator. With a 50 percent input signal, tighten all mounting bolts. Stroke actuator to verify proper alignment.

POSITIONER CALIBRATION

Introduction

Valtek positioners are calibrated at the factory; however, due to shipping and handling, it may be necessary to check the calibration before operating the valve. The XL90 positioner can be calibrated to a range of 3-15; two-way split range, 3-9, or 9-15; and three-way split ranging, 3-7, 7-11, 11-15 psi using the standard feedback spring.

WARNING: When stroking the actuator during calibration, keep hands, hair and clothing away from moving parts. Failure to do so may cause serious personal injury.

Note: Positioners and I/Ps are calibrated at the factory. Use mechanical adjustments in positioner for calibration. Zero and span on the I/P should not be used to calibrate the valve.

For calibration, refer to Figure 6 and proceed as follows:

1.For 3-15 or 3-9 psi range, loosen by hand the zero adjustment locking knob and adjust the zero adjustment knob until the valve begins to stroke with more than 3 psi signal (for 9-15 psi range adjust to 9 psi).

Figure 5: Alignment for Sereg Cams

2.Loosen the span adjustment locking screw no more than 1/8 turn.

3.With a phillips screwdriver adjust the span adjustment so valve is at full stroke with more than 15 psi for 3-15 or 9- 15 psi range (adjust to 9 psi for 3-9 psi range).

4.Return to 3 psi (or 9 psi for 9-15 psi range) and check the zero. Repeat steps 1-4 if necessary.

5.Tighten the zero adjustment lock knob and span adjustment locking screw.

6.Use the same procedure for three-way split range.

7.Connect Cam return spring. See Figure 6.

Positioner Balance Adjustment

CAUTION: Balance pressure is 75 percent of the supply pressure and is the average pressure of output ports 1 and 2. Balance is preset at factory. However, if this adjustment becomes necessary, carefully make this adjustment slowly, allowing the positioner to stabilize. Check after a short while to make sure balance pressure is correct.

Balance adjustment is set at the factory and should not need adjustment. Balance adjustment (output pressure level) permits the equilibrium pressure in both sides of the actuator piston to be raised or lowered. The average actuator pressure level of output 1 or 2 is approximately 75 percent of supply pressure. For single-acting actuators, the balance pressure should be left at the factory setting. If it is necessary to adjust the output pressure level, follow the procedure outlined:

1.If output pressure level is low, before adjusting, check for leaks in tubing connections between positioner and actuator and check supply pressure.

2.Make certain there is no process force or pressure in the valve (The valve should be removed or isolated from the process.)

3.On positioners without gauges, connect gauges to ‘output 1’ and ‘output 2’ lines.

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		Zero Adjustment
	Output 1	Knob
	Zero Adjustment	Span Adjustment
	Lock Knob	Feedback Spring
	Cam Follower Arm	Arm
	(Range Arm)
	Output 2 (shown plugged)	Span Adjustment
		Locking Screw
	Balance	Mounting Holes
	Adjusting Screw
		for Internal
	Feedback	Electronics
	Spring	Cam
	Pilot Relay
	Assembly	Orifice Screw
	I/P Transducer	Cam Spring

Figure 6: Positioner Adjustments

4.Remove rubber cap over balance adjustment screw. (See Figure 6.)

5.Apply full actuator operating pressure to positioner supply port.

6.Set input signal to midscale (9 psi for 3-15 psi span). Output pressure level cannot be adjusted with actuator against valve seat or travel stops. Allow actuator pressure to stabilize.

7.Observe the pressure gauges. If reading is not correct, turn balance adjustment screw about 1/8 turn at a time and wait about 20-30 seconds for pressure to stabilize (counterclockwise to increase pressure). Continue until output pressure level of the higher pressure gauge is approximately 80 percent of supply.

8.Replace rubber cap over balance adjustment screw.

Gain Adjustment Procedure

The unique gain adjustment on the XL90 positioner provides a means to increase or decrease the responsiveness of the valve / actuator / positioner system. Increasing gain makes the valve more responsive and faster, while decreasing gain makes the system less sensitive and slower to respond (with increased damping).

The gain is infinitely adjustable between its highest and lowest settings. For convenience, three marks indicate (H) high, (M) medium and (L) low gain. Most sizes of actuators will respond well to a (M) setting. Unique actuator/valve configurations may require a gain adjustment at the factory or in the field.

1.Before adjusting the gain, place controller on manual and isolate the valve from the process.

2.Turn off supply air to control valve actuator.

3.Using a 5/64-inch allen wrench, loosen both upper and lower lock screws about one half turn. Do not loosen the spacer nut. (See Figure 8.)

4.By grasping adjust lever, carefully rotate gain adjust assembly to desired position.

CAUTION: To avoid damaging gain adjust connecting spring mechanism, make sure both upper and lower gain adjust plates rotate together. When they are rotated to the new position, the connecting spring should be perpendicular to the plates.

5.When the gain is set to the desired position, firmly tighten both lock screws.

6.Turn on the supply pressure. Check actuator responsiveness by providing a step signal to positioner. When gain is set as desired, check valve zero and span calibration and re-calibrate if needed.

7.Return the valve to service.

Calibrating I/P Module Zero and Span Settings

NOTE: Although calibration can be accomplished using the output pressure gauge on the I/P module, its accuracy is ±3 percent. The standard gauge should be removed only for calibration and more accurate calibration equipment of ±0.1 percent of span should be used. The pressure gauge port is 1/8-inch NPT. Calibration manifolds are available from the factory (Part No. 97370).

1.Connect I/P module to a supply pressure between 30 to 150 psi.

2.Remove I/P module housing cover. (See Figure 9.)

Flowserve Corporation, Valtek Control Products, Tel. USA 801 489 8611

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