Distortion during welding

[nabeel3]

I am working in a Reverse osmosis plant construction and we are welding UNS32750 pipes. During the welding of 3 inch pipes we are facing the issue of pipe distortion. The process is Gtaw with a heat input of 1274j/min. Straight polarity. The pipe is bend along vertical axis. Is there any way we can control the bend given the work space limitation.

 

[sivamech]

Where the actual bend is in the image?

 

[racookpe1978]

Physically, what is your detailed process for fitup, tacking, root pass, and final pass?

 

[MJCronin]

Tough situation, given your tight geometry .... Have you talked with AWS people or your fittings supplier ?

Schedule 10S components ? According to my failing memory .... This problem seems to always show up with sched 10S piping, newbie welders and clustered branches

Weld distortion of complex, compact assemblies can sometimes be controlled by the sequence of welding, but you probably already know that ..

The AWS forum has a lot of good information regarding very specific welding problems including distortion

https://app.aws.org/forum/topic_show.pl?tid=15588

This might help too ....

https://www.eng-tips.com/viewthread.cfm?qid=429327

https://www.slideshare.net/cswamy07/distortion-in-welding-58550615

Give us more pictures showing exactly where the distortion occurs and how much distortion that you are allowed by specification (we are not building a watch here)

Keep us informed about your final solution ...

MJCronin
Sr. Process Engineer

 

[EdStainless]

Is this automatic or manual?
Have you worked on starting the welds at different locations (around the tube)?
Getting these welds right is critical for corrosion resistance, make sure that you follow the procedure that you qualified exactly.

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P.E. Metallurgy, consulting work welcomed