PED on piping without hydraulic test

[teokal]

Hi to all of you...
My question is the following: We are prefabricating piping spools in shop, and according to our scope of work, we do not have to perform hydraulic test on them. According to my knowledge, hydraulic test is mandatory for acquiring PED certification. The contractor that will perform the site works (welding, erection hydraulic test etc) is other than us. I believe that it is his responsibility to get PED certification, and not ours.
Any help?
Thank you all...

Only best result in absolutely necessary time

 

[GregLamberson]

teokal

That should have been specified in the purchase order or contract.

Typically, branch reinforcing pads will be tested in the shop. However, hydrotest of individual spools are generally not done (unless specified in the PO), since a system test on the assembled piping is required, at least by all codes I know of.

If you are asked to do it and it is not included in the PO or contract, then prepare a cost estimate for it and submit a change order.

Greg Lamberson, BS, MBA
Consultant - Upstream Energy
Website:

http://www.oil-gas-consulting.com

 

[JohnGP]

teokal,

It is entirely possible that the onsite contractor has responsibility to obtain PED certification. If hydrotest is specifically not in your scope then don't worry about it. The contractor will likely perform hydrotest on completed assemblies of pipework, with Notified Body involvement if necessary.

It would be surprising though if you haven't been requested to provide material certificates, weld procedures, welder qualifications, NDT results, etc, covering your spools. As Greg pointed out though, any certification required from you should have been specified in your contract documents.

Regards,
John

 

[teokal]

Greg, John,
Thank you for your reply...
- there was no requirement in the PO.
- of course there is requirement for all the welding book, material certificates etc; we always work on highest quality levels. we will provide ALL information that No.Bo and other contractor may require.
- According to my knowledge, the No.Bo. will check that our work - up to the point it is done - covers all PED reqs (certs, WPS, WPQ bla bla bla), and then he will proceed to other contractor's work, and later on to the Hydrotest. Finally he will issue the Certificate of Conformity.
All this procedure is familiar, but I am asking you because they started VERBALLY to talk about PED on my work...
I have no problem, if they give to me the erection works, and not to another contractor... Fair, ain't it?

Thank you guys...

Only best result in absolutely necessary time

 

[JohnGP]

Well, good luck on trying to get the onsite work! I suspect it might be too late for that though.

PED requirements on your spools will be satisfied by your documentation, and the NoBo's involvement. If he is involved in your fabrication as well as the welding for the final assembly, and hydrotest, then there should not be a problem. It just means that you don't need to hydrotest your spools because they will be witness hydrotested later.

 

[racookpe1978]

There should be/could be two tests actually - at two different pressures, testing two different requirements:

1) A high pressure hydrostatic test to verify the pipes won't burst, welds are good, no gross flaws in the castings and forgings. (Recently, one pipe engineer here was asking what to do when his foreign-fabricated pipe longitudinal seam did burst open during the hydro test! With quality welders and reputable suppliers, this will very, very rarely fail, but because this test is way above system NOP it is a critical, safety item that must be done carefully.

2) Second is a "the pipes and flanges are re-assembled/field-assembled for the first time/bolted-back-together-after repair-or- replacement, let's see if the flanges leak" type of test.

In the power plants, this test is more routinely done by shift workers - rather than a specially briefed test crew with a special test valve lineup and test engineer, and is done at normal system pressure to look for leaks at the bolted joints: welded joints are pretty much ignored (and many are covered by insulation by this time since the hydro has been finished to check the welded joints).

It could be that your plant/customer is trying to shave money/schedule by doing both at the same time. The leak check/NOP check will be covered by the system hydro.

 

[JohnGP]

Hmm, different situation I think racoopke1978. Sounds like new construction and to satisfy PED there needs to be a hydrotest at minimum 1.43 x Max Allowable Pressure (but if designed to say B31.3, then minimum 1.5 times). Depending on the Category, the NoBo may want to witness and it is Ok for the final hydrotest to be done on site once all the spools are welded/bolted together, provided all the manufacturing records are available.