Size 80 Assembly - Fisher 657 Sizes 80 Instruction Manual

Type 657 Sizes 80 & 100
2. Remove cover band (key 60). Insert a rod of
approximately 1/2-inch (12.7 mm) diameter into a hole
in the adjusting screw (key 12), and rotate the adjust-
ing screw from right to left until spring compression is
relieved. If the actuator has a handwheel, rotate it
counterclockwise, relieving all spring compression.
3. If necessary, the entire actuator may be removed
from the valve body by unscrewing two cap screws
from stem connector (key 26) and removing actuator-
to-bonnet bolting.
4. Unscrew diaphragm casing cap screws and nuts
(keys 22 and 23), and lift off upper diaphragm casing
(key 1).
5. Remove the molded diaphragm (key 2).
6. For actuators without snubber, remove diaphragm
plate and stem (keys 4 and 10) as an assembly. This
assembly can be broken down further, if necessary, by
removing the cap screw (key 3).
7. For actuators with snubber (see figure 7), unscrew
cap screw (key 3), and remove diaphragm plate (key
4). Remove stem connector (key 26). Unscrew cap
screws (key 85), and remove cylinder assembly (key
74) and attached stem and upper seat (keys 10 and
90) from actuator.
To disassemble snubber:
a. Unscrew stem from piston/piston rod assembly
(key 27).
b. Remove retaining rings, cylinder heads, and
piston/piston rod assembly (keys 76, 75, and 27).
Replace packing and O-rings (keys 103, 104, 77
and 105) as required.
8. Remove actuator spring, upper sleeve, and spring
seat (keys 6, 34 and 11).
9. Unscrew cap screws and nuts (keys 62 and 63),
and remove spring case (key 29). Cap screws (key
62) on units with side-mounted handwheel do not use
hex nuts (key 63).
10. For actuators without side-mounted handwheel,
remove adjusting flange (key 36) and attached thrust
bearing and adjusting screw (keys 35 and 12).
11. For actuators with side-mounted handwheel (see
figure 7), unscrew cap screws (key 64), and remove
adjusting flange (key 36) and attached thrust bearing
and adjusting screw (keys 35 and 12). Do not lose the
key (key 47).

Size 80 Assembly

1. Coat the threads of the adjusting flange (key 36)
with Never-Seez Nickel Special lubricant (key 244) or
equivalent. Replace the adjusting flange, adjusting
6
screw, and thrust bearing (keys 36, 12, and 35). Pack
bearing with Lubriplate MAG-1 lubricant (key 241) or
equivalent.
For actuators with side-mounted handwheel, install the
key (key 47) on the adjusting flange (key 36). Coat the
adjusting flange threads with Never-Seez Nickel Spe-
cial lubricant or equivalent. Install the adjusting flange
so that the key engages the slot in the lower sleeve.
Secure adjusting flange with cap screws (key 64). Ad-
just set screws (key 40, figure 7) to eliminate free play
in handwheel bearings.
Over-tightening the set screws will make
handwheel operation difficult.
2. Mount the spring case (key 29) to the yoke (key 9)
using cap screws and hex nuts (keys 62 and 63).
3. Position the lower spring seat (key 11), and slide
the actuator spring (key 6) squarely onto the spring
seat.
4. If the diaphragm plate and actuator stem (keys 4
and 10) were separated, fasten them together using
the cap screw (key 3).
For actuators without a hydraulic snubber, slide
upper sleeve (key 34) onto the actuator stem, and
then slide upper sleeve, actuator stem and diaphragm
plate into the spring case (key 29) so that the spring
(key 6) fits squarely between the diaphragm plate and
the spring seat (key 11).
For actuators with a snubber, thread the actuator
stem and upper spring seat (keys 10 and 90) into the
piston/piston rod assembly (key 27). Install the snub-
ber assembly and attached actuator stem into the up-
per sleeve, spring case adaptor, and spring case (keys
34, 72, and 29). Secure with cap screws (key 85).
5. Place the diaphragm (key 2) with pattern side fac-
ing away from the diaphragm plate (key 4). Align the
holes in the diaphragm and the lower diaphragm cas-
ing (key 5).
6. Position the upper diaphragm casing (key 1) on the
diaphragm (key 2), and align the holes.
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 fol-
lowing tightening sequence with a
manual torque wrench for size 80 and
100 actuators.
Note
Note