longitudinal seam alignment
longitudinal seam alignment
(OP)
G'day,
I have come across a problem in the field were a seam welded pipe has been welded end to end ( circumfrential weld) and the seams (longitudinal) are directly apposed to each other on either side of the cicrumfrential weld, I can not find in B31.3 where it states there must be a minimum amount these two longitudinal seams must be separated a certain amount, I have found the clause in AS/NZS 4458, its in our client specification but i can not find it in ASME B31.3, does such clause exist? I'm 99% sure there must be something in there in regards to this, rolled and welded pipe for pressure purposes i imagine would call the same rules as a pressure vessel? but even than i can not find anything in regards to seam locations in conjunction with other welds.
Thanks in advance, im all ears.
I have come across a problem in the field were a seam welded pipe has been welded end to end ( circumfrential weld) and the seams (longitudinal) are directly apposed to each other on either side of the cicrumfrential weld, I can not find in B31.3 where it states there must be a minimum amount these two longitudinal seams must be separated a certain amount, I have found the clause in AS/NZS 4458, its in our client specification but i can not find it in ASME B31.3, does such clause exist? I'm 99% sure there must be something in there in regards to this, rolled and welded pipe for pressure purposes i imagine would call the same rules as a pressure vessel? but even than i can not find anything in regards to seam locations in conjunction with other welds.
Thanks in advance, im all ears.





RE: longitudinal seam alignment
However if it's in your client spec, make them cut out the weld in question and say at least 1 diameter of pipe and rotate a new spool and weld it in place if you're really concerned about it, but I can't see one joint really casusing you an issue. More than 2 then yes you've got a much higher risk.
My motto: Learn something new every day
Also: There's usually a good reason why everyone does it that way
RE: longitudinal seam alignment
What are your thoughts?
RE: longitudinal seam alignment
AS standards will only apply if they are either mandated by legislation or permissions (unlikely for piping), though this is why the car ones will apply, or specificed in your design basis / scope of work or construction specification (again unlikely, but check).
My motto: Learn something new every day
Also: There's usually a good reason why everyone does it that way
RE: longitudinal seam alignment
I agree with all of Little Inchs comments.
Couple of additional comments
1 If the fabrication code is B31.3 - forget anything to do with AS codes/standards - they are not applicable.
2 Whoever performed the rework should never have cut a pup piece in half - they should have cut it at the flange/pup piece weld - not only looks like crap but very unprofessional.
3 If the proximity of longitudinal seams is in your clients specification and it doesn't comply it is a cut - out, irrespective of what is in B31.3. Specifications always overrule codes/standards.
Good luck,
Regards,
DD