Size 100 Disassembly - Fisher 657 Sizes 80 Instruction Manual

CAUTION
Over-tightening the diaphragm casing
cap screws and nuts can damage the
diaphragm. Do not exceed 50 lbfSft (68
NSm) torque.
Do not use lubricant on these bolts and
nuts. Fasteners must be clean and dry.
7. Insert the cap screws (key 22), and tighten the hex
nuts (key 23) in the following manner. The first four
hex nuts tightened should be diametrically opposed
and 90 degrees apart. Tighten these four hex nuts to
25 lbfSft (34 NSm).
8. Tighten the remaining hex nuts in a clockwise,
criss-cross pattern to 25 lbfSft (34 NSm).
9. Repeat this procedure by tightening four hex nuts,
diametrically opposed and 90 degrees apart, to a
torque of 50 lbfSft (68 NSm).
10. Tighten the remaining hex nuts in a clockwise,
criss-cross pattern to 50 lbfSft (68 NSm).
11. After the last hex nut is tightened to 50 lbfSft (68
NSm), all of the hex nuts should be tightened again to
50 lbfSft (68 NSm) in a circular pattern around the bolt
circle.
12. Once completed, no more tightening is recom-
mended.
13. Mount the actuator on the valve in accordance
with the procedures in the Installation section.

Size 100 Disassembly

Key numbers used in the following procedure are
shown in figure 6 except when indicated.
Two construction variations of the size
100 are based on spring length. Group 1
springs have a free length of 33-1/4
inches (845 mm), and group 2 springs
have a free length of 16-1/2 inches (419
mm).
Note
Note
Type 657 Sizes 80 & 100
WARNING
To avoid personal injury from the precom-
pressed spring force thrusting the upper
diaphragm casing (key 1) away from the
actuator, relieve spring compression (step
1, below), and carefully remove casing cap
screws (key 22) (step 7, below).
1. Remove shroud plate (key 107), loosen jam nut
(key 115), and rotate adjusting nut (key 114) until
spring compression is relieved.
To relieve spring compression when
high spring forces exist, refer to the Ad-
justing Actuator Spring section, and fol-
low the instructions given for size 100
actuators with high spring forces.
2. Remove the pressure tubing or piping from the top
of the diaphragm casing.
3. For actuators with top-mounted handwheel, rotate
handwheel (key 51, figure 9) counterclockwise as far
as it will go, unscrew cap screws (key 109, figure 6),
and remove handwheel and gear case assembly (key
65, figure 9).
4. For actuators without top-mounted handwheel, un-
screw cap screws (key 109), and remove diaphragm
casing cover (key 123).
5. If necessary, remove the actuator from the valve
body by separating the stem connector (key 26) and
removing the actuator-to-bonnet bolting. Separate the
stem connector by loosening the stem locknuts (key
16) and unscrewing the four cap screws.
6. Unscrew and remove actuator stem extension (key
116).
7. Unscrew cap screws (key 22), and remove upper
diaphragm casing (key 1).
8. Remove backup plate, diaphragm retainer, dia-
phragm, diaphragm plate, and washer (keys 13, 110,
2, 4, and 117).
9. Unscrew the nuts that attach lower diaphragm cas-
ing (key 5) to actuator tie rods (key 21).
10. Remove lower diaphragm casing from tie rods
and remove hex jam nut, adjusting nut thrust bearing
(used with group 1 springs only), and spring seat (keys
115, 114, 35, and 11).
11. Remove seal bushing (key 111) and diaphragm
casing cover O-rings (keys 112 and 113) from upper
diaphragm casing (key 123). Replace with new parts if
necessary. Apply Lubriplate MAG-1 lubricant or equiv-
alent to the O-rings.
12. Remove actuator spring (key 6).
Note
7