How to conduct pressure testing on docking valves

There are specialized valve testing machines, and it is possible to commission manufacturers to use them

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The pressure testing of connection valves is usually carried out to verify the valve’s sealing performance, strength, and other related properties. The following are the basic testing steps; when carrying out the tests, it is necessary to refer to relevant **or industry standards, such as GB/T 13927-2008 \"Industrial Valves – Pressure Testing\": 1. **Visual inspection**: Before starting the tests, the valve should first be inspected visually to check for any damage, corrosion, cracks, or other visible defects. 2. **Dimension and appearance inspection**: Check whether the valve’s dimensions, model, pressure rating, etc., meet the requirements, and ensure that there are no significant defects in its appearance. 3. **Strength test**: This is a pressure test of the valve body and valve cover to determine their ability to withstand pressure. With the valve completely closed, a medium of specified pressure (water, air, oil, etc.) is injected into one of the valve ports and held there for a certain period of time to check whether there is any leakage in the valve body and cover. Under normal circumstances, the test pressure is higher than the valve’s normal operating pressure. 4. **Sealing test**: This test checks whether the closing components of the valve can prevent leakage of the medium. During testing, the valve is in a closed state; a medium at a specified pressure is injected from the inlet side, while the outlet side remains closed, or a closed device equipped with a sensitive pressure gauge or level indicator is used to check for any leakage of the medium. Sealing tests are divided into low-pressure sealing tests and high-pressure sealing tests; sometimes a back-sealing test is also included. 5. **Operational performance test**: Operate the valve to open and close it, checking whether it can function smoothly and properly. Certain valves may also require functional testing of their electrical, pneumatic, and other driving mechanisms. 6. **Pressure retention test**: Maintain the test pressure for a specified period of time to check for any leaks in the valve housing and sealing surfaces. 7. **Record test results**: After all tests are completed, the pressure, temperature, testing time, and leakage conditions during the tests should be recorded. If any defects are found, repairs must be carried out or the components must be replaced. When conducting valve pressure testing, it is also necessary to ensure that safety measures are in place to prevent accidents during the test. For special types of valves or those with specific requirements, more detailed testing procedures and standards may need to be followed. Once all tests meet the standard requirements, the valve can be considered qualified and safe for use. .

Pressure testing of valves with butt-welded connections is a significant issue. We currently have two types of presses: one that uses claw pressure and another that uses top pressure; the press using claw pressure has no impact on the valve body or its structure. The pressing force of a top-pressure press acts directly on the valve body, which can easily cause damage to the valve body or its structure; for split-ball valves and gate valves, the pressure testing results are unreliable. For example, in a two-piece ball valve, the two valve bodies are connected by bolts; even if those bolts become loose, the pressing force exerted by the press will still keep the two valve bodies pressed together. This can lead to inaccuracies when testing the strength of the housing. Therefore, it is best to provide a process boss on the valve body for claw pressure application, to facilitate pressure testing.

Good press machines have a balance cylinder design that can balance the pressing force; or the manufacturer can fabricate an internal plug to block the interior hole for pressure testing (the risk is that there will be a pressure-testing blind spot at the ends)

Find a professional valve repair company or pressure testing service that can conduct tests