1) Under normal circumstances, the valve is not tested for strength, but the valve body and valve cover after repair or corrosion damage of the valve body and valve cover should be tested for strength. For safety valves, the constant pressure and return pressure and other tests shall comply with the specifications and relevant regulations.

2), the valve installation should be strength and tightness test. Low-pressure valve spot check 20%, if unqualified should be 100% inspection; Medium and high pressure valves should be checked 100%.

3) During the test, the valve installation position should be in the direction that is easy to check.

4), welded connection form of the valve, with the blind plate pressure test can not be used cone seal or O-ring seal for pressure test.

5), the hydraulic test will be as far as possible to exclude the valve air.

6), the pressure should be gradually increased during the test, and sharp and sudden pressurization is not allowed.

7), strength test and sealing test duration is generally 2-3 min, important and special valves should last 5min. Small diameter valve test time can be correspondingly shorter, large diameter valve test time can be correspondingly longer. During the test, if there is any doubt, the test time can be extended. During the strength test, the valve body and bonnet should not be allowed to sweat or leak. Sealing test, general valves are only carried out once, safety valves, high pressure valves and other essential valves need to be carried out twice. During the test, a small amount of leakage is allowed for low-pressure, large-diameter unimportant valves and valves that are specified to allow leakage; As general valves, power station valves, Marine valves and other valves have different requirements, the leakage requirements should be implemented in accordance with the relevant provisions.