"maximum to be welded"

Date 07-29-2010 12:08

I am trying to determine the qualification range for thickness of weld metal qualified using QW-452.1 and am a little confused. My situation is a person tested using a "super coupon" pipe from Fischer Engineering which is 2 3/4" OD with a wall thickness of 5/8". The pipe was welded with the root and hot GTAW and remainder was SMAW.This is my first experience with these "super coupons", which it appears makes weld metal qualified "Maximum to be welded". I know that typically with the pipe certs we have done before that were multi-process the thickness qualifed was 2t the recorded thickness deposited in the coupon. What is confusing me is it appears that even for a coupon that is 1/2" and over notes 1 and 2 are to apply, but yet thickness qualified is maximum to be welded. I am not sure what to write down for the thickness qualified for each process. Does maximum to be welded mean an unlimited thickness with either process? Please advise if you can. Thanks in advance.

By jon20013 (*****)

Date 07-30-2010 02:39

Maximum to be welded is generally 8 inches, can't remember the exact paragraph as I'm writing from home but you'll see that number there if you look. That said, I may be thinking of a supplementary variable but I'm sure someone with an ASME IX in their hands wil cite specifics. :)

By dlmann

Date 07-30-2010 11:05

Yeah, your right about the 8 inches, I think it come from the WPS qualification thickness ranges.

By js55

Date 07-30-2010 13:00

Maximum to be welded is essentially unlimited. However, the majority of WPS's are limited to 8" and therefore that is the practical limit of the performance deposit. If you had a WPS that allows more than 8" then the welders 'maximum to be welded' would increase in proportion. If this were not the case then ASME IX would say 8" max instead of tying it to the WPS max.
I think maximum to be welded is good language but it does lend itself to some minor misunderstandings until one becomes oriented to its intent.

By jsdwelder (***)

Date 07-30-2010 21:26

OK, so in my situation what makes SMAW the max to be welded. Is it the fact that is was the majority of weld metal used in the test piece? Or maybe because it was the fill and capping process used? Let's for arguement say this 5/8" coupon was welded with 5/16" of GTAW and 5/16" SMAW. Would it still be the SMAW, and only SMAW that is max to be welded? I know you would probably not ever do it this way, but I am curious.

By Shane Feder (****)

Date 07-30-2010 23:58

jsdwelder,
5/16" of GTAW and 5/16" of SMAW would give you a maximum thickness deposited of 5/8" for both processes (2 x T).
The "maximum to be welded" only comes in to play when you deposit 1/2" or greater (with a minimum of 3 layers)
So in your situation you would have 1/8" GTAW (qualifying you up to 1/4") and 1/2" SMAW qualifying you to "maximum to be welded".
Regards,
Shane