Super duplex 24" elbow made by plate.

[mechengineer]

Dear experts,
The super duplex 24" elbow (SA-815) will be made by plate. Question: are there any limits from a code/standard for using two weld lines on the elbow, the half welds to the half? The user wants a single weld seam, but the vendor wants to use double seams for the 24" elbow. It is not mentioned clearly in the contract.
Thanks

 

[mk3223]

It’s a “unlisted” fitting per Code B31.3, in applied for example. IMO, it is the preference to fabricate with either one or two seams once it’s complied with all requirements of the Code and Contract. Of course, it may cost more if additional work is needed, such as fabrication, inspection, etc.

 

[XL83NL]

Just wondering why this would qualify as an unlisted fitting? A815 is listed in B16.9. I don't know A815 in and out, but haven't found a section saying 2 seams are forbidden.

What do you mean by

it is the preference to fabricate with either one or two seams once it’s complied with all requirements of the Code and Contract.

Huub
- You never get what you expect, you only get what you inspect.

 

[EdStainless]

The real questions should be:
1. What weld NDT will be performed
2. What testing will be done to verify the correct final heat treatment?
or if not final annealed that the welds have sufficient corrosion resistance.

The number of welds should not be a concern.

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P.E. Metallurgy, consulting work welcomed

 

[mechengineer]

@EdStainless,
Thanks. Agree with you in technical. If the weld seams requreiment is not metioned in the PO, one weld or two welds shall be deterimed by the elbow vendor.