Pressure testing issues with high-pressure valves
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Dear colleagues in the marine industry, I have a question for everyone. During the construction of high-pressure hydrogenation units, many high-pressure socket valves require pressure testing on site, but most engineering firms do not possess the necessary capabilities for this task. What should be done? Below are several methods that were used in the past; I believe all of them have issues. 1. Pressure testing carried out by the valve manufacturer, with supervision by the supervisor, the construction unit, and the project owner present ； The problem with this approach is that the valve manufacturers are located far away from the project site; issues often arise with the rigid seals during transportation, which renders the process of secondary pressure testing pointless. 2. Hire a professional manufacturer to carry out the pressure testing ； This approach will first lead to the same problems as before; moreover, finding such manufacturers is another challenge. 3. Not subjecting it to pressure testing~~~ Obviously, this is also incorrect. 4. Subjecting it to pressure testing along with the pipes ； This method cannot detect the internal sealing performance of the valve. In short, I really can’t find any good solution; could anyone with more experience suggest another approach? Is there any better way? ? :L
Generally, on-site pressure testing is carried out, and this testing can be done using either air pressure or water pressure; water pressure is usually more suitable for this purpose. The contractor should purchase a pressure testing pump, which doesn’t cost much. A pressure testing flange manifold should be prepared, valves installed, and then pressure applied. If no leaks occur when the pressure reaches 1.5 times the design value and this condition is maintained for 5 minutes, it is considered acceptable
Bro, socket-type valves! Will a regular pressing machine work? It’s necessary to make molds of various types
Damn it, I didn’t realize it was a socket weld; in this case, one can only rely on jacks and rubber seals to fix it, but it’s still possible to do it
Plug-welded valves and threaded valves are difficult to seal at both ends before installation; they can be tested together with the pipeline at the pipeline’s test pressure after installation. It is considered qualified if there is no leakage at the packing box and valve cover sealing surfaces.
The key is to purchase valves of good quality
The contractors usually carry out a second pressure test; it’s better to do that for safety reasons. We found several issues during our tests, but it was good that we carried out the test – otherwise problems would have arisen.