Hydrostatic test at pressure lower than required 1

[Gobio]

Has anybody know if any code justify the performance of the hydraulic test at a pressure lower than required based on complementary tests (as 100% RT...etc)- We have to perform the hydraulic test of a repaired equipment that is already installed in the line and its pressure is quite higher than the one required by the rest of the line -
Thanks.

 

[SectionIX]

The only code that matters is the one that you are required to follow. I've seen guys "code-shopping" with rather negative results.

 

[Frank1344]

API-510 is all about in service pressure vessel repair.

 

[SNORGY]

So if the equipment test pressure is higher than the line test pressure, and the equipment and line are part of a "pressure piping system"' I believe you can pressure test the system to the weakest link. If you go down that path, though, you might have to submit a repair / alteration affidavit and re-register the equipment for service at the lower pressure that is qualified by the system test. Otherwise, to maintain nameplate rating, I think you need to isolate the equipment and test to the higher pressure. Alternatively, the local AI might allow NDE in lieu of testing, but I am not aware of a case where an interpretation was made to the effect that test pressure could be lowered below Code requirements if supplemented by increased NDE.