Flowserve W7000 User Manual
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WORCESTER CONTROLS
Installation
Operation
Maintenance
APEX W7000 Pneumatic Positioner
FCD WCENIM2077-01
Principles of Operation:
The Apex W7000 positioner causes rotation (or linear movement) of valve actuator in proportion to an input signal.
This signal may take the form of pneumatic pressure (Model W7000 and W7600) or electric current (Models
W7100,W7200 W7400 W7500). Supply pressure is directed to the actuator through a precision spool valve. As input
pressure is varied, the balance beam shifts away from its neutral position. The spool also shifts and a differential
pressure is created across the actuator causing rotation (or linear movement). Actuator motion is fed back through the
positioner shaft and cam. Cam rotation causes movement of the feedback arm, changing compression in the
feedback spring, forcing the balance beam and spool back to their neutral position. This shuts off the flow of air to the
actuator and rotation stops.
Installation:
The Apex W7000 positioner can be installed on rotary and linear actuators. Actuators can be either double acting or
spring return. Positioners can be set up for rotation in either direction (direct or reverse acting).
Supply Air Requirements:
Air pressure must be limited to 150 psi for supply and 30 psi for instrument signal to avoid damage to the positioner.
Supply air must be clean, dry and oil free instrument quality air in accordance with ISA S7.3 specifications (dew point
>18 degrees below ambient temperature, particle size <5 microns, oil content <1ppm.
Mounting:
The following instructions apply to rotary actuators only. Linear applications require special mounting and coupling
(consult factory).
1. Mount bracket to actuator. Tighten bolts finger tight only at this time. A standard bracket is available for
mounting to NAMUR compliant actuators.
2. Install coupler (not required if installing to a NAMUR compliant actuator) on actuator shaft making sure it is
centered.
3. Verify that orientation of actuator (and coupler) flats match positioner shaft flats. If necessary, rotate the cam
before installing positioner (see “Cam Installation”). NOTE: Actuator should be in orientation corresponding to
zero input signal.
4. Install positioner onto bracket. Make sure positioner shaft and coupler are engaged and centered. Tighten bolts
finger tight only at this time.
Pneumatic Connections: All pneumatic connections, the supply, both output ports, and instrument ports are
female ¼” NPT. All connections require user-supplied tubing fittings. Caution: Do not use Teflon tape as a pipe
thread sealant. Use only a liquid or paste non-hardening pipe sealant on the threads.
5. Connect positioner ports C1 and C2 to actuator. Port C2 is always connected to the actuator port used to drive
actuator away from its start or fail position (the factor cam setting is full clockwise at minimum input). Port C1 is
connected to the opposite port or may be plugged for spring return actuators. Note: For fail counterclockwise
applications, the cam must be flipped over so the “R” side is facing upwards (see “Cam Installation”).
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6. Connect supply air to port marked “S”.
7. Connect instrument signal air to the port marked “I” for model W7000 and W7600. For models W7100, W7200, or
W7500, connect 4-20 mA and ground (-). For intrinsically-safe applications (Model W7400 only), see separate
intrinsically-safe I/P IOM for barrier requirements and schematics. The I-P is factory calibrated and cannot be
adjusted.
8. Stroke actuator/valve two or three times to align positioner, coupler and actuator. With 50% input (actuator at 45
degrees), tighten all mounting bolts. Stroke actuator/valve again to verify there is no misalignment throughout stroke.
Calibration:
The unit is shipped from the factory pre-calibrated for 90 degree travel (±0.5 degrees rotation – can also be 30/45/60
degrees, see installed cam). For most applications, the valve closed position is much more critical than the valve open
position. Most attention should be made to the valve closed position. Always start calibration procedure by applying
0% input signal, then adjusting zero position.
Caution: Cam pinch points may injure fingers. Be sure to avoid placing fingers and other objects in cam pinch points.
Also avoid touching balance bean and spool while making adjustments as an unpredictable cam rotation may result.
Finally, maintain control of input signal while making adjustments.
After mounting the position on the actuator, check cam setting and if needed, perform a cam adjustment:
Cam Adjustment:
1. Remove cover and indicator.
2. Loosen the screw (1) and turn the cam locking nut (2) counter-clockwise until the cam loosens.
3. Adjust the cam (3) as desired making sure that the ball bearing (4) is riding on an active lobe on the cam.
4. To secure the cam, make sure that the screw (1) is backed out form the locking nut (2) then finger tighten the
locking nut and tighten screw (1).
5. Install and adjust the indicator and re-install cover.
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Calibration Procedure:
1. Apply 0% input signal (0% = 20 kPa, 3 psi, or 4 mA).
2. Wait for steady state. It is important to wait for steady state. On very large actuators, it can take minutes to
establish.
3. Loosen locking screws A and D by about 1 turn. Locking screw D is the angled screw, just above and to the right
of the Zero thumbwheel. If the locking screws are excessively loose, you risk introducing unwanted movement.
4. Adjust “ZERO” position using thumbwheel B. You may find it convenient to turn the thumbwheel by using a
screwdriver blade in the slots.
If using a spring-return actuator, the zero point should be the point at which the positioner output pressure is
still zero, but just begins to increase on any tiny increase of signal. This enables all available spring forces to
be applied to move the valve to its safe position.
If using a double-acting actuator, the zero point is the point at which the actuator will move on any signal
increase.
If the valve jumps upscale on the initial incremental signal change, the cam is likely misaligned. See page 2
for cam alignment instructions. Revivify cam alignment, then recheck the zero adjustment
4b.Retighten locking screw D to lock the Zero Nut. DO not retighten A at this time
5. Apply 100% input signal (100% = 100 kPa, 15 psi, or 20 mA).
6. Wait for steady state.
7. Adjust the “SPAN” setting by turning screw C with a flat-blade screwdriver. This adjustment is accessed by
removing the rubber plug in the bottom of the case. The valve should stroke to 100% of desired travel, but
should not be loaded against a mechanical stop. Slightly decrease the signal to verify that the valve is tracking
the signal value. Span is calibrated when the valve strokes to 100% at exactly 100% signal:
8. Lock the calibration mechanism in place by tightening locking screw A.
9. Apply 0% signal and verify zero position. Recalibrate if necessary.
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Cam Installation:
Introduction: The standard cam (labeled “K1” features linear, 90 degree operation for full 3-15 psi input, 3-9 and 9-15 psi
split ranges, and 3-15 psi 180 degree operation. The factory setting is 3-15 psi, 90 degrees, with “D: (direct) side up for full
clockwise position at 3 psi for 90 degree operation.
Caution: Be sure supply air pressure is removed and no pressure exists in the actuator before adjusting cam.
Cam Adjustment/Replacement:
1. Remove cover and indicator.
2. Loosen the cam lock screw (1) and turn the cam locking nut (2) counter-clockwise until the cam is loose. It may
be necessary to brace the output shaft while loosening the cam locking nut.
3. Adjust the cam (3) as desired, making sure that the cam follower (4) always rides on an active lobe on the cam.
4. Secure the cam by finger tightening the cam locking nut (2) and then tighten the cam lock screw (1) see below
Figure below shows cam setting for Direct Action increasing signal 0-100% (20 – 100 kPa, 3-15 psi) to open. Cam
follower to ride on lobe D, 0-100%
Figure below shows cam setting for reverse action, decreasing signal 100 – 0% (100 – 20 kPa, 15-3 psi) to open. Flip
cam over, cam follower to ride on lobe R, 0-100%
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