Pressure test duration time of valves

[sevenieh]

Almost codes related valves such as ASME B16.34, MSS SP-61, API 598, EN 12266, ISO 5208, ISO 17292, etc describe procedure of the pressure test of valves.

Duration time of the pressure test is decided minimum 180 seconds in above codes.

But I think minimum 180 seconds is too short to check the durability and quality of the welding of valves in comparison to pressure vessels.

So, I think it is right that the minimum duration time of valves should be 30 minutes.

Let me know why the minimum duration time of valves is too short.

And, If there is long minimum duration time decided in any codes, plz let me know.

Thanks.