Fisher A41 Instruction Manual page 11

Figure 5. Optional Shaft-to-Valve Body Bonding Strap Assembly
37A6528-A
VIEW A-A
A3143-2
Stopping Leakage
For PTFE-filled or graphite standard packing arrangements covered in this manual, often leakage from the packing can
be stopped by tightening the packing flange nuts just enough to stop the leak. Use caution when tightening the nuts,
overtightened nuts can damage packing box parts.
D If tightening the packing flange nuts does not stop the leakage, use the following procedures to remove the control
valve assembly from the pipeline, remove the actuator, and to remove and replace the packing parts.
D If the leakage comes from the outside diameter of the packing box, it is possible that the leakage is caused by
scratches on the packing box wall. Carefully inspect the packing box bore and valve drive shaft when the packing is
removed. Use the following steps to remove the actuator, and to remove and replace the packing parts.
Removing the Actuator
WARNING
Refer to the WARNING at the beginning of the Maintenance section in this instruction manual.
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 shut off all pressure lines to the power
actuator, and 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.
WARNING
The edges of a rotating disc have a shearing effect that may result in personal injury. To help prevent such injury, stay clear
of the disc edges when rotating the disc (figure 4).
ACTUATOR
VALVE BODY
A
A
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