Instruction Manual
D103545X012
Control-Disk NPS 14-36
April 2011
11
5. Connect the other end of the bonding strap assembly to the valve flange cap screws.
6. For more information, refer to the Packing Maintenance section below.
Maintenance
Valve parts are subject to normal wear and must be inspected and replaced as necessary. The frequency of inspection
and replacement depends upon the severity of service conditions.
Key numbers in this procedure are shown in figure 9 unless otherwise indicated.
WARNING
Avoid personal injury from sudden release of process pressure. Before performing any maintenance operations:
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Always wear protective gloves, clothing, and eyewear when performing any maintenance operations to avoid personal
injury.
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Disconnect any operating lines providing air pressure, electric power, or a control signal to the actuator. Be sure the
actuator cannot suddenly open or close the valve.
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Use bypass valves or completely shut off the process to isolate the valve from process pressure. Relieve process pressure
on both sides of the valve. Drain the process media from both sides of the valve.
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Vent the power actuator loading pressure.
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Use lockout procedures to be sure that the above measures stay in effect while you work on the equipment.
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The valve packing box may contain process fluids that are pressurized,
even when the valve has been removed from the
pipeline.
Process fluids may spray out under pressure when removing the packing hardware or packing rings, or when
loosening the packing box pipe plug.
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Check with your process or safety engineer for any other hazards that may be present from exposure to process media.
Removing and Replacing the Actuator
Refer to the appropriate actuator instruction manual for actuator removal and replacement procedures.
Packing Maintenance
The Control-Disk valve is designed so the packing can be replaced without removing the valve from the process
pipeline.
CAUTION
For non‐ENVIRO‐SEAL packing: Tighten the packing follower nuts only enough to prevent shaft leakage. Excessive
tightening will accelerate wear of the packing and could produce higher friction loads on the valve stem.
Usually, packing leakage can be eliminated by merely tightening the hex nuts (key 15) located above the packing
follower (key 11) while the valve is in the pipeline. However, if leakage continues, the packing must be replaced.
For PTFE ENVIRO‐SEAL packing systems, refer to the separate instruction manual, ENVIRO‐SEAL Packing System for
Rotary Valves, D101643X012, (see figure 10).
