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Up Topic Welding Industry / ASME Codes / Combine Process GTAW+SMAW repair by GTAW(SAME WPS) on SMAW
- - By Toey TNDT (**) Date 08-07-2015 05:59
Dear Sir ,

I suspect about Repair WPS (USE itself) .IF GTAW + SMAW (WPS) after repaired by Grinding .

Welder who welded this joint . Can use GTAW(with filler rod) weld on SMAW or not ?

Why its can weld and/or Why its can't weld ? (For ASME IX Code & D1.1 Code)

I must do Repair Procedure or its need not ?

Regards
Parent - - By pipewelder_1999 (****) Date 08-07-2015 19:18
I think the majority of your questions can be answered by reviewing the applicable code of construction.

ASME Sec IX does not address repairs. The applicability of a procedure to a specific joint is dependent upon the variables listed within the WPS wether it be for repair or an original joint.

There are no restrictions within the ASME codes related to the applicability of GTAW over SMAW provided the WPS is qualified for the ranges to be used. 

The ranges within the WPS would dictate where they can be used however some applications may require more detailed controls to be enforced during repair welding.

A repair procedure is always a good idea even if not required by the specific code.

AWS D1.1 addresses qualifcation differently and a review of clause 3 and clause 4 should get you up to speed.

Gerald
Parent - By Jovi Zhu (**) Date 08-11-2015 03:17
More details need to be known before an answer is given.

From the questions and based on my experience, I can ASSUME that the original WPS was used for GTAW root and the rest by SMAW. Because there might be a reasonable joint thickness to necessitate the use of SMAW process besides GTAW for the rest passes, preheat is a concern for non-austenitic carbon or low alloy steels. And let me ASSUME more...the filler metals (for both GTAW and SMAW) match the base metal an it's not a dissimilar metal weld (DMW) we are dealing with....

It should be noted that for similar cases often the WPSs written by experienced engineers specify lower preheat temperature for GTAW root because of the non-flux/low hydrogen GTAW process and less joint restraint at the beginning. But for the rest SMAW passes higher preheat temperature is to be specified. Now we've found cracks by MT/PT and an 1" in depth groove after crack removal, are we going to fill this groove with GTAW following the original WPS with lower preheat temperature?

An approved repair procedure including qualified procedure(s) is always better than assumptions by the ones other than the responsible welding engineer.
Up Topic Welding Industry / ASME Codes / Combine Process GTAW+SMAW repair by GTAW(SAME WPS) on SMAW

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