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Pipeline Welding (2)

Posted: 22 Jun 2010, 03:23
by lotra
Hi Colleagues
Is there any limitation about the distance between weld line and support in gas or liquid hydro carbons above ground pipelines?
thanks in advance
Lotra

Re: Pipeline Welding (2)

Posted: 22 Jun 2010, 04:43
by arcpro
This limitation has never been observed by me in any of the codes / standards or project specifications.
What I have observed is the placement of supports directly below the welds even at some places. And at some instances, welded supports are also attached directly to the pipe containing circumferential weld nearby. Before welding of support directly on the weld line, fabricator provides a notch in the support plate just to cater for the capping and welder takes care of that area that is not to weld up side of circumferential or any longitudinal weld.
What I understand is that the care must be taken where PWHT is critical / mandatory like in the case of low alloy piping. Before to weld the piping support nearby any weld, confirm that the existing weld is post weld heat treated (if reqd.) already.

Re: Pipeline Welding (2)

Posted: 22 Jun 2010, 11:22
by mechcolor
Lotra,
What's the type of piping support you are talking about? Welded or non-welded?

Re: Pipeline Welding (2)

Posted: 22 Jun 2010, 12:08
by lotra
hi
i mean non-weldwd support (plain H support without anchor or clamps)
did u see any limitation about welded supports?
lotra

Re: Pipeline Welding (2)

Posted: 22 Jun 2010, 12:38
by mechcolor
I came along a situation one time when the piping support (non-welded type) was directly coming underneath a weld joint. Considering the severity of the service especially operating temperature, we decided not to do anything as there was no expansion or movement expected during the service.
I haven't seen any such limitation in any of the codes or standards also.
So no limitations, no worries.

Re: Pipeline Welding (2)

Posted: 24 Jun 2010, 05:48
by lotra
Hi
Thanks Friends
Lotra