Fisher 667 Instruction Manual page 12

Type 667 Size 30-76 & 87
CAUTION
Over-tightening the diaphragm cap
screws and nuts (keys 13 and 14) can
damage the diaphragm. Do not exceed
27 NSm (20 lbfSft) torque.
Do not use lubricant on these bolts and
nuts. Fasteners must be clean and dry.
5. Position the diaphragm casing (key 1, figures 6, 7,
and 8), mounting plate (key 158), travel stops (key
152), if used, and cap screws (key 154) on the dia-
phragm. Install the cap screws and hex nuts (keys 13
and 14, figures 6, 7, and 8) and tighten in the following
manner.
6. The first four bolts tightened should be diametrically
opposed and 90 degrees apart. Tighten these four
bolts to 13 NSm (10 lbfSft).
7. Tighten the remaining bolts in a clockwise, criss-
cross pattern to 13 NSm (10 lbfSft).
8. Repeat this procedure by tightening four bolts, dia-
metrically opposed and 90 degrees apart, to a torque
of 27 NSm (20 lbfSft).
9. Tighten the remaining bolts in a clockwise, criss-
cross pattern to 27 NSm (20 lbfSft).
10. 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.
11. Once completed, no more tightening is recom-
mended.
12. If necessary, screw the extension rod (key 150
into the connector (key 27). Slide the guide plate (key
157) onto the extension rod (key 150). For size 45
through 76, place the spacer (key 253) on top of the
guide plate (key 157). If necessary, replace the exten-
sion rod (key 150). Slide the handwheel body (key
148) over the extension rod, position the handwheel
body on the spacer (key 253), align the holes, and in-
sert and tighten the cap screws (key 161).
13. Lubricate and install the thrust bearings (keys 181
and 180), install the bearing retainer (key 182), install
the castle nut (key 166) on the extension rod. Do not
overtighten the castle nut on the bearing. Install the
cotter pin (key 167). Replace the cap (key 247).
12
Note
14. Refer to the Assembly portion of the Actuator
maintenance section.
For size 70 and 87 actuators handwheels (figure
12):
Refer to figure 12 for top-mounted handwheel assem-
blies.
1. If removed, slide the handwheel (key 58) onto the
end of the handwheel screw (key 160), and snap the
retaining ring (key 60) into place.
2. Generously coat the threads of the handwheel
screw (key 160) with lubricant (key 239 or equivalent).
Turn the screw into the handwheel body (key 148).
3. If necessary, install the extension rod (key 150) into
the connector (key 27) and tighten it. Position the
handwheel body (key 148) on the diaphragm casing
(key 1, figures 6, 7, and 8), and align the holes. Insert
the cap screws (key 154). Finger tighten the screws.
4. If travel stops were used, return the travel stops to
their original positions as recorded in the proceeding
Disassembly steps. Tighten the screws and travel
stops.
When you replace actuator diaphragms
in the field, take care to ensure the dia-
phragm casing bolts are tightened to the
proper load to prevent leakage, but not
crush the material. Perform the following
tightening sequence with a manual
torque wrench for size 30-76 and 87 ac-
tuators.
CAUTION
Over-tightening the diaphragm cap
screws and nuts (keys 13 and 14) can
damage the diaphragm. Do not exceed
27 NSm (20 lbfSft) torque.
Do not use lubricant on these bolts and
nuts. Fasteners must be clean and dry.
5. Slide the extension rod (key 150) into the hand-
wheel screw (key 160), and position the diaphragm
casing (key 1, figures 6, 7, and 8) with the attached
parts on the diaphragm. Install the cap screws and hex
nuts (keys 13 and 14, figures 6, 7, and 8) and tighten
in the following manner.
6. The first four bolts tightened should be diametrically
opposed and 90 degrees apart. Tighten these four
bolts to 13 NSm (10 lbfSft).
Note
Note