Fisher NPS 12 Instruction Manual page 6

Large ET and ED Valves
July 2014
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 and relieve any actuator spring precompression.
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 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.
D 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 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, and use lock-out procedures to prevent injury while you work on
the equipment.
Figure 2. Lubricator and Lubricator/Isolating Valve
10A9421-A
AJ5428-D
LUBRICATOR/ISOLATING VALVE
A0832-2
Note
Whenever a gasket seal is disturbed by removing or shifting gasketed parts, a new gasket should be installed upon reassembly.
This is necessary to ensure a good gasket seal because the used gasket might not seal properly.
Note
If the valve has ENVIRO-SEAL live-loaded packing or HIGH-SEAL ULF live-loaded packing installed, see the Fisher instruction
manuals titled ENVIRO-SEAL Packing System for Sliding-Stem Valves (D101642X012) or HIGH-SEAL ULF Live-Loaded Packing
System (D101453X012) (as appropriate) for packing instructions.
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LUBRICATOR
31
Instruction Manual
D103553X012