about hydrostatic test in process plant or petrolium?

Question

i wanna know if fluid was liquid that material of pipe is selected stainless steel (321) and design temperature was 350 c and design pressure was 25 barg , would you tell me that what would test pressure be?

Answer 1

Per the ANSI piping code, the usual test pressure for hydrostatic tests is 1.5 times the design pressure. You could go higher to allow for high temperature but that really serves little purpose. You stated the design temperature as being 350 C but did not state the normal operating temperature.

Most components such as pressure vessels, exchangers, pumps, filters, etc are manufactured to the ASME or similar codes and are capable of withstanding a 1.5 test pressure. There are some unusual cases where a special piece of equipment might not take such a test and there are allowances for that sort of thing. All piping components should be able to take a 1.5 times design test pressure. If not, that should be determined by the design engineer and so stated on the construction drawings.

The primary reason for the hydrostatic pressure is to assure the integrity of the system and the components. It is not unusual in the case of high temperature applications for there to be minor leaks at some joints as the system heats up. Testing at a higher pressure really doesn't help with this problem

Answer 2

The test is usually conducted at the room temperature and thus will be much higher. Each specification for the pipe (ASTM A - 312 for example) specifies a test pressure depending on the pipe's ID and wall thickness.

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