Tack weld and qualification

Date 05-29-2012 08:49

1)Does a welder need qualification for tack welding olny? If yes where does that exist in ASME.
2) I have i WPS that qualifies me to weld pipe with thickness range 1-25 mm. But now i have to weld pipe 10'' with 28mm wall thickness. Obviously i need i new WPS. Where can i find in ASME the demanding procedure to qualify my welder to weld 28mm pipe

Thanks in advance

By Eutectic (**)

Date 06-01-2012 11:01

1) Our internal specifications state that all tack welds be made with a qualified WPS and welder. Generally Clients don’t want random welders getting anywhere near a job. For a myriad of reasons.
Depending on what you fabricate however or whether or not the tack is removed or incorporated your welder may or may not be required to be qualified. See ASME VIII div 1 UW 31 (c) for example.
2) First of all I am assuming your WPS is in accordance with ASME IX. There is no range of qualification that can qualify you from 1 to 25mm see ASME IX QW 451.1. what was the PQR wall thickness? Secondly you do not only need a WPS but a whole new PQR if you don’t have one in had for this thickness range. Check essential variables in ASME IX QW 300 for welding performance