Fisher Control-Disk Instruction Manual page 11

Instruction Manual
D103298X012
6. Use the appropriate procedures below for installing packing.
D Install the packing as shown in figure 4.
D With graphite ribbon packing, stack the packing rings and packing washers together, and slide the stack into the
packing box as far as it will go while carefully avoiding trapping air between the rings.
D Install the anti‐blowout ring (key 40) in the groove on the drive shaft (key 10).
D Install the packing follower and, if used, the packing flange.
D Install the packing flange nuts, and tighten them only far enough to stop leakage under normal operating
conditions.
D For oxygen service applications, attach the bonding strap assembly (key 131, figure 3) to the shaft with the clamp
(key 130, figure 3), and connect the other end of the bonding strap assembly to the valve body with a cap screw
(key 35). Secure each cap screw with a hex nut (key 36).
7. Mount the actuator and adjust the closed position of the valve, per the Actuator Mounting section on page 18 of
this manual, before returning the valve to service.
8. When placing the control valve into operation, check around the packing follower for leakage; retighten the
packing flange nuts as required according to accepted bolting procedures.
For valves with ENVIRO‐SEAL packing systems:
1. Isolate the control valve from the line pressure, release pressure from both sides of the valve body, and drain the
process media from both sides of the valve. If using a power actuator, also shutoff all pressure lines to the power
actuator, release all pressure from the actuator. Use lock‐out procedures to be sure that the above measures stay in
effect while you work on the equipment.
CAUTION
When removing the actuator, use a wheel puller to separate the actuator parts from the valve shaft. Do not drive the
actuator parts off the valve shaft because this could damage valve trim components.
2. Remove the actuator per instructions in separate actuator instruction manuals, then remove the cap screws and
nuts (keys 35 and 36). Remove the clamp (key 130, figure 3) if the strap (key 131, figure 3) is used.
3. Loosen the two packing hex nuts evenly to remove spring tension, then remove the nuts.
4. Remove the packing flange and spring pack assembly. The spring pack assembly consists of the spring stack and
packing follower. The spring stack is retained on the packing follower by an O‐ring. Remove the anti‐blowout ring
(key 40) from the driveshaft (key 10). Remove the anti‐extrusion washer, the packing set, and the packing ring.
CAUTION
The valve shaft surface condition is critical in making and maintaining a good seal. If the valve shaft surface is scratched,
nicked, dented, or worn, replace the valve shaft before replacing the packing system.
5. Inspect the existing valve shaft. If necessary, replace the valve shaft as described in the Replacing the Disk, Shafts, or
Bearings section.
6. Install the new packing system components as described in the ENVIRO‐SEAL Packing System for Rotary Valves
Instruction Manual (D101643X012).
Control-Disk Valve
June 2017
11