Flowserve XL90 User Manual
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.
T o 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 rackand-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 48-1
Flow Control
Installation, Operation, Maintenance Instructions
XL90 Series
High-Performance
Positioner
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.
48-2 Flowserve Corporation, Valtek Control Products, Tel. USA 801 489 8611
Figure 1: XL90 Positioner Schematic for Air-to-Open
Figure 2: Positioner Mounting with NAMUR shaft
Figure 3: Positioner Mounting with Double D Shaft
and Linkage
Supply Seat
Upper Pilot
Poppet
Exhaust Seat
Port No. 1
Restriction
Supply
Pilot Valve
Capsule
Exhaust Seat
Port No. 2
Lower Pilot
Poppet
Supply Seat
Piston
Cylinder
Balance Adjustment Feedback Spring Zero Adjustment
Range Adjust
Screws
Cam
Feedback
(shaft)
Instrument Signal
Upper Diaphragm
Lower Diaphragm
Flapper
Detecting
Nozzle
Input Capsule
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.
Flowserve Corporation, Valtek Control Products, Tel. USA 801 489 8611 48-3
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
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).
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 915 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.
48-4 Flowserve Corporation, Valtek Control Products, Tel. USA 801 489 8611
Figure 5: Alignment for Sereg Cams
Figure 4: Alignment for Accord Cams
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 48-5
Figure 6: Positioner Adjustments
Output 1
Zero Adjustment
Lock Knob
Cam Follower Arm
(Range Arm)
Output 2 (shown plugged)
Balance
Adjusting Screw
Feedback
Spring
Pilot Relay
Assembly
I/P Transducer
Zero Adjustment
Knob
Span Adjustment
Feedback Spring
Arm
Span Adjustment
Locking Screw
Mounting Holes
for Internal
Electronics
Cam
Orifice Screw
Cam Spring
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