Requirements for a covered weld 2

[Asmongold]

Hello,

I am just wondering if somewhere in B31.3 there is something that covers the NDE requirements for a weld that gets covered by something? Most shops I worked at get 100% MPI or LPI if it’s stainless as the weld is getting covered.

Current situation we have trunnions that get welded to the pressure pipe then get covered with a repad.

Would you not 100% the weld underneath? As a rule of thumb?

- I looked in B31.3 couldn’t find anything to my exact question, closest thing was 328.5.4 (h) “Examination and any necessary repairs of the completed weld between branch and run shall be made before adding a pad or saddle.”

- I looked in our client spec. Couldn’t find anything.

If this is the case would I just follow exactly whatever the weld matrix we were given say at 5% of all attachments and give these welds no “special” treatment?

Thank you for you’re response in advance.

 

[LittleInch]

Are these non penetrating support welds?

I'm not sure B31.3 really deals with these is they are not exposed to the fluid.

I think I would look to inspect any weld which could create a crack or burn through the pipe if this is a support weld that can't be inspected during a pressure test.

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

 

[Asmongold]

These supports (trunnions) are not penetrating they just get welded to the side of the pressurized pipe.
Then that weld that is attached to the pressurized pipe gets covered with a repad.

So of course you would conduct a visual on the weld I’m more referring to if you would 100% NDE like MPI or LPI the underneath weld prior to the repad going on.

I don’t want the question to get too wordy but these welds fall within our 5% lot which are for ALL attachments on our weld matrix but from what I seen previously our weld matrix is not detailed.
Example being our matrix states 100% PMI but if you look in the spec 100% PMI means just on pressure-containing welds.
Where some inspectors were PMI supports that were not on the pressurized section.

So my question is if there is some rule of thumb or industry rule for covered welds and getting 100% NDE prior to being covered?

 

[weldstan]

If you've set a 5% NDE of all attachment welds, stay with it. There is no B31.3 requirement for same - pressure welds, yes. Most shops which I dealt with in the past did not 100% NDE such attachments to pressure parts and non pressure attachments. Most did visual only and depending on the constraints of the contract specifications including B31.3, percentaage and type of NDE to be performed.

When we welded attachmets to hardenable alloys like those in P No.4, 5, 15E etc. more NDE of such welds was required up to 100%.

 

[Asmongold]

Thank you very much for taking the time to respond and clarify this.
I was definitely over thinking it.