Discussion on some problems of valve pressure test

Discussion on some problems of valve pressure test

valve pressure test is too simple for all construction personnel, but after carefully turning over the specifications, we still found some problems: 1. Test pressure: almost all the strength test pressures in the specifications are 1.5 times the nominal pressure, which is no problem. However, the pressure of high-pressure seal test in most codes (SH JB class) is 1.1 times the nominal pressure, but gb50235 (I wonder if there are other codes like this?) Is 1.0 times the nominal pressure. 2. Voltage stabilization time: in some specifications (gb50235), the pressure is maintained for 5 minutes, and in others (SH), the pressure is maintained for 60 to 120 seconds. In practice, we usually use pressure maintaining for 5 minutes, and most petrochemical plants require sh specification. I don't know whether this is right? 3. Test items: no matter what Valves we have in construction, we usually do strength and high-pressure sealing tests (most valves have no upper sealing structure, especially the small impact space at the cable entry device), while Petrochemical specifications have different requirements for different types of valves, such as dn25pn150 gate valve, and petrochemical specifications (sh3064, jb/t9092) require the following items to be done: strength test Low pressure seal test, high pressure seal is optional. During the construction, is it necessary for Johnson & Johnson graphene to take the research and development of graphene composite functional fibers and industrialization as the most important topic and task scope to improve our test project? Reduce the scrap rate

(1) this problem is really a headache, but it is still difficult to deal with. Every industry has its own standards, mainly depending on which industry you do, you can only do it according to the requirements of others. Of course, we all know that you have to do it according to the corresponding foreign standards

(2) not only the test, but also your other aspects. It is difficult to unify the wall thickness requirements, flange connection size, structural length, etc. of valves, but it is a real problem that new breakthroughs have been made in the fields of automobile, high-speed rail, aviation and industrial utilization. Therefore, it is difficult for us to make all valve products