Fisher 657 - Manual (Page 10)

Instruction Manual
D100307X012
657 Size 80 and 100 Actuators
December 2010
10
10. Tighten the remaining hex nuts in a clockwise, criss‐cross pattern to the final torque value that is specified in table
2 for the diaphragm material being used.
11. After the last hex nut is tightened complete another tightening sequence, this time in a circular pattern around
the bolt circle to the final torque value that is specified in table 2 for the diaphragm material being used.
12. Once completed, no more tightening is recommended.
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 5 except when indicated.
Note
Two construction variations of the size 100 are based on spring length. Group 1 springs have a free length of 845 mm (33‐1/4
inches), and group 2 springs have a free length of 419 mm (16‐1/2 inches).
WARNING
To avoid personal injury from the precompressed 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.
Note
To relieve spring compression when high spring forces exist, refer to the Adjusting Actuator Spring section, and follow 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 8) counterclockwise as far as it will
go, unscrew cap screws (key 109, figure 5), and remove handwheel and gear case assembly (key 65, figure 8).
4. For actuators without top‐mounted handwheel, unscrew 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, diaphragm, diaphragm plate, and washer (keys 13, 110, 2, 4, and 117).
9. Unscrew the nuts that attach lower diaphragm casing (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).