Casing-Mounted Travel Stops - Fisher 667 Instruction Manual

Type 667 Size 30-76 & 87
23. After the last bolt is tightened to 27 NSm (20 lbfSft),
all of the bolts should be tightened again to 27 NSm
(20 lbfSft) in a circular pattern around the bolt circle.
24. Once completed, no more tightening is recom-
mended.
25. Return the actuator to service after completing the
Loading Connection procedure in the Installation sec-
tion and the procedures in the Adjustments section.

Casing-Mounted Travel Stops

If repeated or daily manual operation is
expected, the actuator should be
equipped with a side-mounted hand-
wheel rather than a casing-mounted
travel stop or top-mounted handwheel.
The side-mounted handwheel is de-
signed for more frequent use as manual
operator.
Casing-mounted adjustable travel stops (shown in fig-
ures 16 through 20) are available to limit travel in the
down direction (extending the actuator stem) or in the
up direction (retracting the actuator stem). The travel
stop in figure 16 is a down travel stop, the travel stop
in figure 17 is an up and down travel stop, and the
travel stops in figures 18, 19, and 20 are up travel
stops.
Use the locknuts (key 151, figures 16 and 17), stem
(key 150, figure 18), handwheel (key 58, figure 19) or
cap screw (key 177, figure 20) to set the point at which
the travel stop limits travel. Be sure to tighten the lock-
nuts and replace the cap (key 149, figures 16 and 18;
key 247, figure 17) after setting the travel stop.
Instructions are given below for disassembly and as-
sembly. Perform the disassembly only as far as neces-
sary to accomplish the required maintenance; then,
begin the assembly at the appropriate step.
Key numbers are shown in figures 16 through 20.
1. Remove the cap (key 149 or 247) if the travel stop
uses one. For down travel stops, loosen the locknuts
(key 151, figures 16 and 17) so that the stop is not
causing any spring compression.
16
Note
2. Bypass the control valve, reduce loading pressure
to atmospheric, and remove the tubing or piping from
the connection in top of the yoke (key 73, figures 6, 7,
and 8).
3. For down travel stops, turn the spring adjuster (key
74, figures 6, 7, and 8) out of the yoke toward the stem
connector (key 31) to relieve all the compression in the
spring (key 18).
4. For style 11 travel stops (figure 17), unscrew the
cap screws (key 161), and make sure that the guide
plate (key 157) can turn between the handwheel body
(key 148) and the mounting plate (key 158).
5. Use a wrench on the nuts (key 151) to unscrew the
extension rod (key 150). Remove the rod, the hand-
wheel body (key 148), and the attached parts.
6. Unscrew the hex nuts and cap screws (keys 14 and
13, figures 6, 7, and 8) from the diaphragm casings.
Lift off the upper diaphragm casing (key 1, figures 6, 7,
and 8) and, for the style 11 travel stop, the mounting
plate (key 158). For styles 10, 12 and 13, the travel
stop assembly will be removed with the casing.
7. Note and record the position of travel stops (key
152) relative to the cap screws (key 154) for use in
assembly. Unscrew the travel stops and cap screws,
and remove either the mounting plate (key 158) or the
handwheel body (key 148) and attached parts.
8. Separate the stem (key 150) and screw (key 160,
figure 17) from the handwheel body.
9. Before reassembling, lubricate parts indicated by
key 239 in figures 16 through 20. Use lubricant (key
239 or equivalent).
10. Reassemble parts in the reverse order of removal.
11. When replacing the cap screws (key 154) and, if
used, the travel stops (key 152), be sure to return
them to their original position as recorded in step 6.
CAUTION
Over-tightening the diaphragm cap
screws and nuts (keys 13 and 14), fig-
ures 6, 7, and 8 can damage the dia-
phragm. Do not exceed 27 NSm (20 lbfSft)
torque.
12. Install the cap screws and nuts (keys 13 and 14,
figures 6, 7, and 8) and finger tighten. Tighten the dia-
phragm cap screws and nuts to 27 NSm (20 lbfSft)
torque in a crisscross pattern.
13. Return the spring adjuster (key 74, figure 6, 7,
and 8) to its original position. Re-adjust the travel stop.