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Up Topic Welding Industry / General Welding Discussion / Welding slip on flanges
- - By pipe1105 Date 01-10-2006 00:41
Was wondering about the correct way to weld slip on flanges? Currently we recess the pipe about 1/8" to 1/4" in from the face of the flange and Tig weld the inside w/ 1/8" ER70s2. Then we weld the outside of the flange to the pipe, Tig root (1/8" ER70s2) and cover w/ 7018. Is this the preferred method or is their a better way?
Parent - By Shane Feder (****) Date 01-10-2006 03:06
Hello Pipe 1105,
There is really no need to use the GTAW. It is advantageous to use GTAW on small bore piping ( 2" and under) but anything bigger is fine to weld entirely with E7018.
Regards,
Shane Feder
Parent - By medicinehawk (**) Date 01-10-2006 09:22
We usually recess the flange, 1/2" to 3/8" and whether you use GTAW or SMAW to weld it...depends on the WPS you are welding to. If a welder is certified (to do either process)...than like Shane says (and IF the weld spec allows) you should be able to stick weld the whole thing with 7018 or it can be welder's preference depending on the size of the pipe.
They do not ususally give us a choice......it the pipes are to be SMAW-ed (per wps) than that is what we do. On a slip-on flange, we'll run a pass of 6010 and then go with 7018 over that. We recess back 1/2" to stay away from the raised face or mating surface of the flange and still put in a nice fillet on the ID of the pipe, you know, sometimes those slip-on's have plenty of slop in em'.
Parent - - By fbrieden (***) Date 01-10-2006 13:32
Thickness of the pipe, plus 1/8".
Parent - - By jon20013 (*****) Date 01-10-2006 13:48
I like that answer; thickness of pipe + 1/8."

The ASME Codes I'm familiar with do not have a minimum engagement length/depth however there should be adequate material left to perform a suitable weld from the OD. In addition, it's highly preferable to keep from burning the inside edge of the flange diameter.

Quite often slip on flanges are preferred where permitted by design to ease fit-up issues.
Parent - - By fbrieden (***) Date 01-10-2006 14:45
That was our in-house procedure when I worked for the Turbo Division of Ingersoll-Rand. The AI's never had a problem with that set back and it allowed us to have the working room we needed, especially when the pipe/flange were in position.
Parent - By jon20013 (*****) Date 01-10-2006 16:30
Well, it was a very fine response, in my humble opinion! ;-)
Up Topic Welding Industry / General Welding Discussion / Welding slip on flanges

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