Instruction manual

Instruction Manual
D500248X012
A31D Valve
April 2014
10
Note
Standard PTFE packing is composed of a partially conductive carbon-filled PTFE female adaptor with PTFE V-ring packing. Standard
graphite packing is composed of all conductive graphite ribbon packing. Alternate shaft-to-valve body bonding is available for
hazardous service areas where the standard packing is not sufficient to electrically bond the shaft to the valve (see the following
step).
4. Attach the bonding strap assembly (key 131, figure 4) to the shaft with the clamp (key 130, figure 4).
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, 10, or 11 unless otherwise indicated.
WARNING
The valve closes with a shearing action. To avoid personal injury, keep hands, tools, and other objects away from the valve
while its being stroked.
Avoid personal injury from sudden release of process pressure. Before performing any maintenance operations:
D Do not remove the actuator from the valve while the valve is still pressurized.
D Always wear protective gloves, clothing, and eyewear when performing any maintenance operations to avoid personal
injury.
D 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.
D 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.
D Vent the power actuator loading pressure.
D Use lock-out procedures to be sure that the above measures stay in effect while you work on the equipment.
D The valve packing box may c ontain 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.
D Check with your process or safety engineer for any additional measures that must be taken to protect against process
media.
Removing and Replacing the A ctuator
Refer to the appropriate actuator instruction manual for actuator removal and replacement procedures. The actuator
stops or travel stops must limit the rotation of the valve shaft. See the CAUTION below.
CAUTION
When using an actuator, the actuator travel stop (or actuator travel stop, for actuators without adjustable stops) must be
adjusted so the disk stop in the valve does not absorb the output of the actuator. Failure to limit the actuator travel can
result in damage to the valve, shaft(s), or other valve components.