Fisher 657 - Manual (Page 11)

Instruction Manual
D100307X012
657 Size 80 and 100 Actuators
December 2010
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 lithium grease lubricant to the O‐rings.
12. Remove actuator spring (key 6).
Size 100 Assembly
Note
Units using a group 2 spring require one spring seat (key 11) on each end of the spring (key 6); units using a group 1 spring require
only one spring seat on the diaphragm end of the spring as shown in figure 5.
1. Place the spring and spring seats (keys 6 and 11) inside the spring case.
2. For actuators using a group 1 spring, pack the thrust bearing (key 35) with lithium grease lubricant (key 241). Place
bearing on the spring seat.
3. Screw the hex jam nut and adjusting nut (keys 115 and 114) onto the actuator stem.
4. Install the lower diaphragm casing (key 5) on the actuator tie rods (key 21). Secure with hex nuts.
Note
Before installing diaphragm plate (key 4), rotate adjusting nut (key 114) until the top of the actuator stem is 264 mm (10‐3/8
inches) above the inside surface of the lower casing (key 5).
When installing diaphragm (key 2), be certain that the rubber side of the diaphragm faces away from the spring.
CAUTION
To avoid product damage, smooth the edge of the diaphragm to avoid wrinkling, and be careful that the diaphragm fold
does not get pinched when the upper casing (key 1) is installed.
5. Install washer, diaphragm plate, diaphragm, diaphragm retainer, and backup plate (keys 117, 4, 2, 110 and 13).
6. Apply lithium grease lubricant (key 241) to the thread on the diaphragm end of the actuator stem (key 10).
7. Position the upper diaphragm casing (key 1) on the diaphragm (key 2), and align the holes.
Note
If backup plate (key 13) interferes with installation of upper casing, rotate adjusting nut (key 114) to move the plate.
Note
When you replace actuator diaphragms in the field, take care to ensure the diaphragm 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 80 and 100 actuators.