The standards and specifications for valve pressure testing are as follows:

1. Under normal circumstances, the valve is not subjected to a strength test, but the valve body and bonnet or valve body and bonnet damaged by corrosion should be subjected to a strength test after repair. For the safety valve, its constant pressure, reseating pressure, and other tests shall comply with the requirements of its manual and relevant regulations.
2. The valve installation should be tested for strength and tightness. 20% of the low-pressure valves should be inspected randomly, if they are unqualified, they should be inspected 100%; medium and high-pressure valves should be inspected 100%.
3. During the test, the valve installation position should be in a direction that is easy to check.
4. For valves in the form of a welding connection, when the pressure test with the slap plate fails, the pressure test can be carried out with a conical seal or an O-ring seal.
5. The valve air should be excluded as much as possible during the hydraulic test.
6. The pressure should be gradually increased during the test, and rapid and sudden pressure increase is not allowed.
7. The duration of the strength test and tightness test is generally 2~3min, and important and special valves should last for 5min. The test time of small-diameter valves can be correspondingly shorter, and the test time of large-diameter valves can be correspondingly longer. During the test, the test time can be extended if in doubt. During the strength test, the valve body and valve cover are not allowed to sweat or leak.
8. The tightness test of the closing parts is not required for the throttle valve, but the strength test and the tightness test of the packing and gasket shall be carried out.
9. During the pressure test, the valve closing force can only be closed by the normal physical strength of one person; it is not allowed to use tools such as levers (except torque wrenches) to apply force. When the diameter of the handwheel is greater than or equal to 320mm, two people are allowed to close together. .
10. For valves with upper seals, the packing should be taken out for a tightness test. After the upper seals are closed, check whether there is leakage. When testing with gas, check with water in the stuffing box. When doing the packing tightness test, the upper seal is not allowed to be in the right position.
11. For any valve with a driving device, when testing its tightness, the driving device should be used to close the valve and conduct a tightness test. For manually actuated devices, a seal test for manually closing the valve shall also be carried out.
12. After the strength test and the tightness test, the bypass valve installed on the main valve shall be tested for strength and tightness at the main valve; when the main valve closing part is opened, it should also be opened.
13. During the strength test of cast iron valves, tap the valve body and bonnet with a copper hammer to check for leakage.
14. When the valve is tested, except for the plug valve that allows the sealing surface to be oiled, other valves are not allowed to be oiled on the sealing surface.
15. When the valve is pressure tested, the pressing force of the blind plate on the valve should not be too large, so as not to deform the valve and affect the testing effect (if the cast iron valve is pressed too tightly, it will be damaged).
16. After the pressure test of the valve is completed, the water in the valve should be removed in time and wiped clean, and the test record should be made.