failed hydro then pneumatic test as record
failed hydro then pneumatic test as record
(OP)
an ASME pressure vessel is hydro'd and leaks were found and repaired. instead of redoing the hydro a pneumatic pressure test was performed and used as the pressure test of record - is that allowable?
also, how does this square with ASNT?
TIA
also, how does this square with ASNT?
TIA





RE: failed hydro then pneumatic test as record
I've not answered your question, but the situation you describe would scare me.
RE: failed hydro then pneumatic test as record
My shop would not allow it at all. Not sure what the AI would say.
I would never have thought to ask him the question.
RE: failed hydro then pneumatic test as record
I'd say if the AI allows it, its allowed.
Regards,
Mike
RE: failed hydro then pneumatic test as record
I would ask for a copy of their NCR (make sure it has the disposition with AI sign-off). Then ask for their pneumatic test procedure, and actual test documentation, to make sure it conforms to UG-100.
-TJ Orlowski
RE: failed hydro then pneumatic test as record
isn't a hydro an NDE method?
further, if the hydro is successful and a pneumatic test does not follow then i would consider that improper procedures. that is like - we'll do it this way and if it doen't work we'll do it that way!
RE: failed hydro then pneumatic test as record
The other thing is that the pneumatic test is at a lower pressure than the hydrostatic pressure test. Seems like cheating a bit there.....
Was this signed off by an AI?
RE: failed hydro then pneumatic test as record
besides could'nt dry air be used to dry out the area of repairs and then re-do the hydro.
RE: failed hydro then pneumatic test as record
if it was just a pinhole in a porous weld, acceptable to put a weldpass and pneumatic re-test, it the hydro failed:
crack or other serious discountinuity, then a re-hydro is imperative.
genblr
RE: failed hydro then pneumatic test as record
RE: failed hydro then pneumatic test as record
1) Was the U-1 signed by an AI?
2) Was a test method specified on the drawing?
-TJ Orlowski
RE: failed hydro then pneumatic test as record
will find out next week the answers to both questions.
RE: failed hydro then pneumatic test as record
Hydrotest is not considered a non-destructive test (even if it doesn't leak!). Hydrotest and pneumatic tests are proof tests. A round-about way of demonstrating above, is Code requires NDE certifications be per ASNT SNT-TC-1A. SNT-TC-1A has many different NDE methods but nothing about hydrotest or pnuematic test.
JR97
RE: failed hydro then pneumatic test as record
thanks for that info.