Packing Maintenance - Fisher A41 Instruction Manual

CAUTION
Damage to the disc (key 3) sealing surfaces may occur if the disc is not closed when the valve is being removed from the
pipeline. For fail open actuators, it may be necessary to apply loading pressure to the actuator to retain the disc in the
closed position while removing the valve from the pipeline.
2. Be sure the disc is in the closed position before attempting to remove the valve from the pipeline or flanges.
For Fail-Open Actuators: It will be necessary to provide a temporary loading pressure to the actuator to move the valve
disc to the closed position. Observe the above Warning when closing the valve. If a loading pressure is required, use
caution when working with the valve. If the loading pressure is disconnected, the disc will open rapidly.
3. With the disc in the closed position, remove line bolting. Remove the valve assembly from the pipeline, and place
the actuator/valve assembly on a flat working surface.
4. If a grounding strap is used (see figure 5), remove the hex nut to release the end of the strap. Remove the clamp
(key 130) and strap (key 131).
5. Note the orientation of the actuator with respect to the valve body. Also, remove the actuator cover to note the
orientation of the actuator with respect to the valve drive shaft (see figure 7).
When re-assembling the valve assembly, you will need to correctly position the mark on the end of the valve drive
shaft and the valve body, with respect to the actuator drive shaft. Refer to the Actuator Mounting section and figure 7
for the location of the mark on the actuator end of the valve drive shaft. Additional information is provided in the
actuator manual to assist with disassembly, re-assembly, and travel adjustments.
6. Remove the actuator mounting screws (key 14).
7. Remove the actuator from the valve, and remove the valve/actuator coupling.

Packing Maintenance

WARNING
Refer to the WARNING at the beginning of the Maintenance section in this instruction manual.
Standard graphite packing is composed of all conductive packing rings. PTFE-filled packing has a partially conductive
packing ring (such as a carbon-filled PTFE female adaptor) to electrically bond the shaft to the valve body.
If the valve is equipped with the optional ENVIRO-SEAL Packing System, refer to the separate ENVIRO-SEAL Packing
System for Rotary Valves Instruction Manual (D101643X012) for packing maintenance procedures.
When replacing the packing, it is recommended that you remove the control valve assembly from the pipeline.
Valve/actuator travel adjustments must be made with the valve out of the pipeline.
Disassembly
Part locations and key numbers are shown in figures 5 and 11.
1. Remove the packing flange nuts (key 101) and the packing flange (key 114).
2. Remove the old packing rings, using a formed hook.
CAUTION
Carefully use the hook. Avoid scratching the drive shaft or packing box wall. Scratches on valve surfaces can cause leakage.
[Note: the packing box ring (key 107) can remain in place when replacing the packing only.]
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