Instruction Manual
D500242X012
A31A Cryogenic-Rotary Valve
February 2019
8
5. For more information, refer to the Packing Maintenance section below.
Installing Single‐Flange Valves
WARNING
The edges of a rotating valve disk have a shearing effect that may result in personal injury. To avoid personal injury, keep
clear of the disk edges when rotating the disk.
2. Properly orient the valve according to the specific application. For optimum shutoff, install the valve for reverse
flow.
3. Position the valve between the flanges. Be sure to leave enough room for the flange gaskets. Install the lower flange
bolts.
4. Select the appropriate gaskets for the application. Flat sheet, spiral wound, or other gasket types, made to the ANSI
B16.5 group standard or user's standard, can be used on the valve depending on the service conditions of the
application. Install the gaskets and align the valve and the gaskets.
5. Install the remaining bolts.
6. Tighten the flange bolts in an alternating criss‐cross fashion to a torque value of one‐fourth of the final bolting
torque. Repeat this procedure several times increasing the torque value each time by a fourth of the final desired
torque. When you get to the final torque value, tighten each flange bolt again to allow for gasket compression.
Note
The optional graphite ribbon packing and metal bearings are composed of all conductive material to electrically bond the shaft to
the valve for hazardous area service, as opposed to the non‐conductive PTFE packing and bearings.
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.
WARNING
Avoid personal injury from sudden release of process pressure. Before performing any maintenance operations:
D
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 either side of the valve.
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Vent the power actuator loading pressure and relieve any actuator spring precompression.
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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 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.