PetroStreet

At one of our plants, we have huge welding scope of stainless steel piping ranging from 1"NPS to 48"NPS in different schedules. During welding of larger dia especially above 24"NPS purging is becoming difficult for us. Also repairs from radiography have also to be performed and purging becomes nearly impossible for installed /erected pipelines.
We have been advised by the Contractor to use non-purging wires for the same. I have seen AWS 5.22 which enlists flux cored wires for GTAW and Contractor has provided us the WPS and PQR also. I need to know do we have to re-qualify the welders on non-purging wires (R-308LT1 AWS 5.22) or the same welders doing with normal bare wire (ER-308 AWS 5.9) can perform welding without re-qualification. I have seen the F-No. which is '6', same for both AWS 5.9 and AWS 5.22 as per ASME Sec. IX. Is this enough? Can I continue using the same welders with non-purging wire also? Also please share some experience regarding use of non-purging wires?

Thanks.

Non-purging filler wires can be used in the situations you are facing as code allows their usage as per AWS 5.22.
Regarding welders qualification, if the welder has now to weld without purging then as per ASME Sec. IX, re-qualification is mandatory although the F-No. is staying the same for both the wires.
While performing the re-qualification of welders, perform visual test from pipe I.D also just to see the appearance of the weld to be sure that no oxidation has occurred. Additionally, radiography shall also be done. These checks will ensure that the things will go right on the actual job.

Hope this would help.

Ashfaq,
Can you share the information of manufacturer of subject wires, if you experienced any?