Stopping Leakage; Replacing Packing - Fisher CV500 Instruction Manual

Instruction Manual
D101640X012

Stopping Leakage

All maintenance procedures in this section may be performed with the valve body (key 1) in the line.
For packings other than spring‐loaded packing, leakage around the packing follower (key 14) may be stopped by
tightening the packing flange nuts (key 16). If leakage cannot be stopped in this manner, replace the packing
according to the Replacing Packing procedure in this manual.
If the packing is relatively new and tight on the drive shaft (key 3), and if tightening the packing nuts does not stop
leakage, it is possible that the shaft is worn or nicked so that a seal cannot be made. If the leakage comes from the
outside diameter of the packing, it is possible that the leakage is caused by nicks or scratches on the packing box wall.
Inspect the shaft and packing box wall for nicks or scratches when performing the following procedures.

Replacing Packing

Note
If the valve has ENVIRO‐SEAL live‐loaded packing installed, see the manual entitled Fisher ENVIRO‐SEAL Packing System for Rotary
Valves (D101643X012).
This procedure may be performed without removing the actuator from the valve if adding PTFE/composition packing
rings as a temporary measure. However, the actuator must be removed if replacing any other kind of packing or if the
metal packing parts (keys 14, 17, and, if used, 18) need to be replaced.
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, 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
To avoid increased leakage, increased valve component wear or possible damage to the valve body, ball, shaft, and
bearings resulting from a sharp blow to the shaft, use a wheel puller to separate the actuator parts from the drive shaft.
Do not drive the actuator parts off the drive shaft since this could move the valve bearings, shaft, and ball away from
proper alignment, causing improper seating of the ball. Such misalignment may result in damage to valve components if
the valve is returned to service without disassembly and inspection of the valve ball alignment.
2. If necessary, remove the cap screws (key 25) and hex nuts (key 26). Then remove the actuator while referring to the
actuator instruction manual for assistance.
3. Remove the packing nuts (key 16). For NPS 3 through 8, remove the packing follower (key 14). For NPS 10 and 12,
remove the packing flange (key 45) and then remove the packing follower (key 14).
CAUTION
In the following step, take care not to scratch the valve shaft or packing box wall, as this may cause leakage.
CV500 Valve
June 2017
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