Flowserve Logix 1200e LGAIM0044 - Manual (Page 13)

Flowserve Corporation, Valtek Control Products, Tel. USA 801 489 8611 44-13
Stem Position Sensor
The position feedback assembly transmits valve posi-
tion information to the processor. This is accomplished
by means of a rotary position sensor that connects to
the valve stem through a feedback linkage. To provide
for accurate tracking of the pin in the slot, the follower
arm is biased against one side of the slot with a rotary
spring. This spring also automatically moves the posi-
tion feedback assembly to its limit in the unlikely event
of failure of any component in the linkage.
Stem Position Sensor Replacement
(Figure 13, 20)
1. Make sure valve is bypassed or in a safe condition.
2. Disconnect the power and air supply to the unit.
3. Remove the main cover and disconnect rotary
position sensor wires from collector board.
4. Remove the two screws from rotary position sensor
and remove the sensor from the housing.
5. Turn position sensor shaft until the dot on the slot is
oriented with the wires on the pot (Figure 13).
6. Insert the position sensor into the shaft with wires
pointing toward the main PCB assembly. Turn the
position sensor clockwise until bolting slots align
with the housing screw holes and the wires on the
sensor protrude over the main PCB assembly tray.
7. Carefully center position sensor on the shaft bore,
insert and tighten the screws. Do not over tighten.
8. Route wires along the position sensor and recon-
nect to collector board.
Mounting to Linear Mark One Valves
(See Figure 14)
The tools required for the following procedure are:
9 / 16 -inch open-end wrench
7 / 16 -inch box wrench
3 / 8 -inch open-end wrench
1. Remove washer and nut first from follower pin
assembly. Insert pin into the appropriate hole in fol-
lower arm, based on stroke length. The stroke
lengths are stamped next to their corresponding
holes in the follower arms. Make sure the
unthreaded end of the pin is on the stamped side of
the arm. Reinsert lock washer and tighten nut to
complete follower arm assembly.
2. Slide the double-D slot in the follower arm assem-
bly over the flats on the position feedback shaft in
the back of the positioner. Make sure the arm is
pointing toward the customer interface side of the
positioner. Slide lock washer over the threads on
the shaft and tighten down the nut.
3. Align the bracket with the three outer mounting
holes on the positioner. Fasten with 1 / 4 -inch bolts.
4. Screw mounting bolt into the hole on the yoke
mounting pad nearest the cylinder. Stop when the
bolt is approximately
3 / 16-inch from being flush with
mounting pad.
5. Slip the large end of teardrop shaped mounting
hole in the back of the positioner/bracket assembly
over mounting bolt. Slide the small end of teardrop
under mounting bolt and align the lower mounting
holes.
6. Insert lower mounting bolt and tighten bolting.
7. Slide appropriate pin slot on the take-off arm, based
on stroke length, over follower arm pin. The appro-
priate stroke lengths are stamped by each pin slot.
8. Position the take-off arm mounting slot against the
stem clamp mounting pad. Apply Loctite 222 to
take off arm bolting and insert through washers into
stem clamp. Torque to 120 in-lbs.
9. Center the take-off arm on the rolling sleeve of the
follower pin.
10.Align take-off arm with top plane of the stem clamp
and tighten bolting.
Figure 13: Stem Position Sensor
Orientation
Sensor
Cable
Feedback Shaft
Housing Stem Position
Sensor
Bearing
Stem Position
Sensor Dot