Manufacturing large size pipes and number of welding seams

[TalG]

Hello everyone,

I was wondering, according to A312, one welding seam for pipes up to 14" and two welding seams for pipes larger than 14" are allowed.
What is the case with very large stainless steel pipes, ~80" for example, which 2 sheets of metal are not enough in term of width to complete the pipe?
Is it allowed to add a third sheet and a third welding seam? is there any alternative solution?

Thank you very much,

 

[fel3]

Is spiral weld pipe an option? Cement mortar lined and coated steel pipe (with a spiral weld steel core) is common in the waterworks industry. However, the largest I have dealt with is 36" and the steel wasn't stainless.

Regardless, I suggest that you search for "spiral weld pipe" and see what's available. My quick search didn't turn up stainless, but that doesn't mean it isn't available.

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"Is it the only lesson of history that mankind is unteachable?"
--Winston S. Churchill

 

[EdStainless]

I have seen 120" made with one weld, you can buy 40' long plates and turn them sideways, but the pieces are only 8' long.
I have seen 16' wide plate being rolled, but again you end up with short pieces, usually 40'.
8' wide is the widest coil made which limits you to 60" OD with one weld and 92" with three welds.
People usually go to spiral welded for large diameter such as A134 and A409.
Some of the large diameter welded tube/pipe specs don't specify the number of welds .....

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P.E. Metallurgy, consulting work welcomed

 

[TalG]

Perfect, thank you guys.