Hydrotest Test of HDPE PIPE failure twice 2

[Fahad-566]

I work as a QC Engineer (mechanical) for the client and the contractor has failed doing a hydrotest twice for the same Work inspection request.
I want to issue a Nonconformity Report however I don’t know what reference should put in the NCR
can any one help me please

 

[LittleInch]

Either reference the scope of works or the relevant part of the design code being used and stated in the contractual documents.

Is that what you mean?

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[Fahad-566]

I couldn’t find nothing in the scope of work nether the method of statements or the schedule q of the project I mean is there anything in the international standard that says a hydrotest shall not fail twice or something like that

 

[LittleInch]

Well what design code are you using?

Also your OP isn't clear.

Do you mean the contractor has failed to undertake the test OR

The test has been performed and failed twice?

PE has a nasty habit of creeping and getting thinner as each test goes on so there is something wrong here. But if you do a test and it doesn't pass then that is a clear Non conformity as he can't provide a test certificate. That must be somewhere in the scope.

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[Fahad-566]

Yes the contractor has performed the test twice and failed the first time I gave them a second chance to perform the test again however they performed it again and failed again and regarding “Non conformity as he can't provide a test certificate. That must be somewhere in the scope” I couldn’t find anything in the scope of work as reference in my NCR

 

[weldstan]

A hydrotest procedure should always be made prior to hydrotesting, especially that used for HDPE pipe. I have more than once had to retest HDPE pipe in firewater service, in a few instances, several times. I never wrote an NCR on HDPE installations because the test was finally concluded successfully. The only time I wrote an NCR on a failed fire water hydrotest was when obvious leakage occurred but the leakage could not be found within a short period of time. About a month or two later when the leakage site was detected and repairs made, the hydrotest was repeated successfully.

Whereas the hydrotest was required and failed, you can always write an NCR. The contractor must then address the NCR to correct the non-conformance to include retesting.

 

[Smith55]

What was the reason for the failure of hydrotest? Was a leak at a flange or joint found? As mentioned in one of the replies above, HDPE naturally creeps and so the pressure will drop during hydrotest. For this reason, in my experience, there is a special procedure and acceptance criteria for HDPE piping hydrotest which takes into account the creep characteristics. You may want to check if the procedure being used is suitable for HDPE piping.

 

[mk3223]

The Code did specify the piping installation should pass the test, such as hydro test, pneumatic test, etc., but it doesn't specify the number of the tests allowed. IMO, If the Contractor doesn't want to resolve the test problem after the tests failed twice, you as an Inspector should just report it with the fact to the Project Owner. And, the Owner and Procurement may need to involve to resolve it with Contractor.

 

[FacEngrPE]

Few Codes contain all of the information needed to develop a pipe hydrostatic test procedure. I agree that issuing an NCR after one failed test is reasonable, but not always necessary, it depends on the nature of the failure.

A document titled GUIDANCE FOR FIELD HYDROSTATIC TESTING OF HIGH DENSITY POLYETHYLENE
PRESSURE PIPELINES: Owner’s considerations, planning, procedures, and checklists
Plastic Pipe institute TN-46, 2021 and attached. This document makes reference to several standards (ASTM, ASME, ect).

Additional possibly useful information for figuring out why the hydro tests are failing can be found in the Plastic Pipe Institute website and their publications, which for the most part are offered free.