Back Purging Requirements for Stainless Steel Welding
Back Purging Requirements for Stainless Steel Welding
(OP)
Hello,
We are fillet TIG welding stainless support pads to 316L 4''sch10S pipe.
It is fillet weld but is back purging argon through pipe still required ?
Thx.
We are fillet TIG welding stainless support pads to 316L 4''sch10S pipe.
It is fillet weld but is back purging argon through pipe still required ?
Thx.





RE: Back Purging Requirements for Stainless Steel Welding
RE: Back Purging Requirements for Stainless Steel Welding
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P.E. Metallurgy, Plymouth Tube
RE: Back Purging Requirements for Stainless Steel Welding
So, the answer is dependent on the service conditions and the application.
Best regards - Al
RE: Back Purging Requirements for Stainless Steel Welding
Depending on the extent of heat tint and the process fluids, heat tinted areas may corrode: https://www.nickelinstitute.org/~/media/Files/Tech....
Thanks.
Pradip Goswami,P.Eng.IWE
Welding & Metallurgical Specialist
Ontario,Canada.
ca.linkedin.com/pub/pradip-goswami/5/985/299
All provided answer are personal opinions or personal judgements only. It's not connected with any employers by any means.
RE: Back Purging Requirements for Stainless Steel Welding
Very good info from all the previous posters.
Will add a little bit more as I have done a huge amount of this type of work years ago on Sch 10 & Sch 5 stainless (without purge).
Support pads are almost always thicker than the actual pipe material so direct all of the heat from the TIG torch to the pad and not the parent material.
In a normal fillet weld you would aim the arc towards the junction of the pad and pipe.
Aim the arc as far away from the pipe as you can and the molten S/S filler metal will flow down and fuse with the pipe material without causing the pipe material to oxidise or get a heat tint.
You couldn't do the same with C/S but it is one of the pleasures of working with S/S,
Hope that helps,
Cheers,
DD
RE: Back Purging Requirements for Stainless Steel Welding
RE: Back Purging Requirements for Stainless Steel Welding
Thank You All.
RE: Back Purging Requirements for Stainless Steel Welding
B.E.
You are judged not by what you know, but by what you can do.