Precautions for pressure testing of a Plug Valve
1. When testing the pressure of the whole system, the plug valve should be kept in full open position, which means that the full open position shall remain unchanged after installation. Do not test the pressure in the half-open position of the valve, which could lead to the faster wastage of sealing grease. When testing the pressure of body, the plug valve should be left fully open, instead of half-open. When testing the pressure of seat, the plug valve should remain fully closed.
2. Don't use the plug valve as blind plate, that is to say, don't close the plug valve when testing the pressure of body. According to API 6D, the pressure-bearing capacity cannot exceed the max 1.1 times than the design pressure, and the valve must not be closed in bigger pressure.
3. Don't loosen or tighten the adjustment screw in the bottom of the body and disassemble valve parts. Should consult the supplier and gain approval before loosening or tightening the adjustment screw, and after adjustment, must make a record of it.
4. The injection bolt equipment must be:
7203 or 733LT sealing grease of us. (733LT is used in winner)
1 - 6 Inch valves use 400D injection gun of us.
1 - 36 Inch valves use 10-90 injection pump of us.
5. When using a injection pump in the testing phase, there is no natural gas or compressed air at the testing site, it is necessary to coordinate actively to use nitrogen or argon.
6. The bottom flange of the Plug Valve is the pressure sealing piece with the locating piece. And the bottom flange cannot touch the ground directly or bear the outer pressure.
7. When a problem occurs, please read the item of "All kinds of phenomenon, handling ways & precautions of Plug Valve that may be encountered in the site".