Low pressure, medium pressure, and high-pressure valves should be subjected to strength test and tightness test. Alloy steel valves should also be subjected to spectrum analysis on the shell one by one, and the material should be reviewed.
1. Strength test of the valve
The strength test of the valve is a test when the valve is open to check the leakage on the outer surface of the valve. For valves with PN≤32MPa, the test pressure is 1.5 times the nominal pressure, the test time is not less than 5min, and there is no leakage at the shell and packing gland.
2. Tightness test of valve
The test carried out in the fully closed state of the valve is to check whether there is leakage on the sealing surface of the valve. The test pressure, except for butterfly valves, check valves, bottom valves, and throttle valves, should generally be carried out at nominal pressure. At working pressure, it can also be tested with 1.25 times the working pressure, and the sealing surface of the valve disc is qualified.