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The standards and specifications for valve pressure testing are as follows:
1. In general, valves are not subjected to strength tests, but after repair, the valve body and valve cover, or those that have been corroded or damaged, should undergo strength tests. For safety valves, their constant pressure, reseating pressure, and other tests should comply with their instructions and relevant regulations.
2. The installation of valves should undergo strength and sealing tests. 20% of low-pressure valves shall be randomly inspected, and if they are found to be unqualified, 100% inspection shall be conducted; Medium and high pressure valves should be inspected 100%.
3. During the experiment, the valve should be installed in a direction that is easy to inspect.
4. For valves with welded connections, if pressure testing with blind plates fails, cone sealing or O-ring sealing can be used for pressure testing.
5. During hydraulic testing, try to eliminate valve air as much as possible.
6. During the experiment, the pressure should gradually increase and sudden pressure increase is not allowed.
7. The duration of strength test and sealing test is generally 2-3 minutes, and important and special valves should last for 5 minutes. The testing time for small-diameter valves can be correspondingly shorter, while the testing time for large-diameter valves can be correspondingly longer. If there are any questions during the experiment, please feel free to
Extend the testing time. During the strength test, it is not allowed for the valve body and valve cover to sweat or leak.
8. The throttle valve should not undergo a sealing test for the closing component, but a strength test and a sealing test for the packing and gasket should be conducted.
9. During the pressure test, the valve closing force only allows one person's normal physical strength to close it; Do not use tools such as levers to apply force (except for torque wrenches). When the diameter of the handwheel is greater than or equal to 320mm, two people are allowed to close it together.
10. Valves with upper seals should have their packing removed for a sealing test. After the upper seal is closed, check for leaks. When using gas for testing, fill the stuffing box with water for inspection. When conducting a packing sealing test, it is not allowed for the upper seal to be in a sealed position.
11. For valves with driving devices, the sealing test should be conducted by closing the valve with the driving device. For manual drive devices, a sealing test should also be conducted to close the valve with motion.
12. The bypass valve installed on the main valve after strength and sealing tests shall undergo strength and sealing tests on the main valve; When the main valve closure is opened, it should also be opened accordingly.
13. During the strength test of cast iron valves, a copper hammer should be used to lightly tap the valve body and valve cover to check for leaks.
14. When testing valves, except for plug valves that are allowed to be coated with oil on the sealing surface, other valves are not allowed to be coated with oil on the sealing surface for testing.
15. During valve pressure testing, the blind plate should not exert too much pressure on the valve to prevent deformation and affect the test results (cast iron valves may also be damaged if pressed too tightly).
16. After the valve pressure test is completed, the accumulated water inside the valve should be promptly drained and wiped clean, and the test records should be kept.
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1. In general, valves are not subjected to strength tests, but after repair, the valve body and valve cover, or those that have been corroded or damaged, should undergo strength tests. For safety valves, their constant pressure, reseating pressure, and other tests should comply with their instructions and relevant regulations.
2. The installation of valves should undergo strength and sealing tests. 20% of low-pressure valves shall be randomly inspected, and if they are found to be unqualified, 100% inspection shall be conducted; Medium and high pressure valves should be inspected 100%.
3. During the experiment, the valve should be installed in a direction that is easy to inspect.
4. For valves with welded connections, if pressure testing with blind plates fails, cone sealing or O-ring sealing can be used for pressure testing.
5. During hydraulic testing, try to eliminate valve air as much as possible.
6. During the experiment, the pressure should gradually increase and sudden pressure increase is not allowed.
7. The duration of strength test and sealing test is generally 2-3 minutes, and important and special valves should last for 5 minutes. The testing time for small-diameter valves can be correspondingly shorter, while the testing time for large-diameter valves can be correspondingly longer. If there are any questions during the experiment, please feel free to
Extend the testing time. During the strength test, it is not allowed for the valve body and valve cover to sweat or leak.
8. The throttle valve should not undergo a sealing test for the closing component, but a strength test and a sealing test for the packing and gasket should be conducted.
9. During the pressure test, the valve closing force only allows one person's normal physical strength to close it; Do not use tools such as levers to apply force (except for torque wrenches). When the diameter of the handwheel is greater than or equal to 320mm, two people are allowed to close it together.
10. Valves with upper seals should have their packing removed for a sealing test. After the upper seal is closed, check for leaks. When using gas for testing, fill the stuffing box with water for inspection. When conducting a packing sealing test, it is not allowed for the upper seal to be in a sealed position.
11. For valves with driving devices, the sealing test should be conducted by closing the valve with the driving device. For manual drive devices, a sealing test should also be conducted to close the valve with motion.
12. The bypass valve installed on the main valve after strength and sealing tests shall undergo strength and sealing tests on the main valve; When the main valve closure is opened, it should also be opened accordingly.
13. During the strength test of cast iron valves, a copper hammer should be used to lightly tap the valve body and valve cover to check for leaks.
14. When testing valves, except for plug valves that are allowed to be coated with oil on the sealing surface, other valves are not allowed to be coated with oil on the sealing surface for testing.
15. During valve pressure testing, the blind plate should not exert too much pressure on the valve to prevent deformation and affect the test results (cast iron valves may also be damaged if pressed too tightly).
16. After the valve pressure test is completed, the accumulated water inside the valve should be promptly drained and wiped clean, and the test records should be kept.
