Instruction Manual
D100399X012
EW Valve
July 2017
11
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Do not remove the actuator from the valve while the valve is still pressurized.
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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 pneumatic 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.
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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 additional measures that must be taken to protect against process
media.
1. Isolate the control valve from the line pressure, release pressure from both sides of the valve, 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.
2. Disconnect the operating lines from the actuator and any leak‐off piping from the bonnet. Disconnect the stem
travel indicator parts and stem locknuts from the valve stem threads.
WARNING
To avoid personal injury or property damage caused by uncontrolled movement of the bonnet, loosen the bonnet by
following the instructions in the next step. Do not remove a stuck bonnet by pulling on it with equipment that can stretch
or store energy in any other manner. The sudden release of stored energy can cause uncontrolled movement of the bonnet.
Note
The following step also helps to provide additional assurance that the valve body fluid pressure has been relieved.
24). Loosen these nuts approximately 3 mm (1/8 inch). Then loosen the body‐to‐bonnet gasketed joint by either
rocking the bonnet or prying between the bonnet and valve body. Work the prying tool around the bonnet until the
bonnet loosens. If no fluid leaks from the joint, proceed with bonnet removal as described in the following steps.
CAUTION
To avoid damage to the seating surface caused by the valve plug and stem assembly dropping from the bonnet after being
lifted part way out, temporarily install a valve stem locknut on the valve stem when lifting the bonnet. The locknut
prevents the valve plug and stem assembly from dropping out of the bonnet.
5. Completely remove the hex nuts (key 16) and carefully lift the bonnet off the valve body.
