Qualification Single-Vee and Double-Vee

Date 05-07-2004 01:32

Dear pple,

I have an existing PQR for welding a single-vee groove joint of base metal thickness T = 60mm.

Now I have a project which requires us to weld a double-vee groove joint of thickness 110mm.

The base metal and welding electrode are the same in both cases and according to ASME Code IX QW-451, the PQR I have is qualified for thickness up to max. 2T (120mm).

So can I use my existing PQR to weld the double-vee joint since its thickness 110mm is less than 120mm?

Or I have to do a new PQR using a double-vee groove test piece?

Thanks

By jon20013 (*****)

Date 05-07-2004 14:16

You need to let us know which welding process is being used before we can comment intelligently. You may look the essential variables up yourself in QW-25X. Since you used the term 'electrode' in your post I am making an assumption you are talking about SMAW and, if so, a change of groove design would be considered 'non-essential' as it is with nearly all of the processes. This means you may modify the joint details without requalifying the WPS but you should revise the WPS to allow the change. Maybe to avoid future concerns in this area you could simply include a statement which address most 'typical' joint designs. By the way, just as a clarification; you state the PQR is qualified for 60mm, depending on which Code governs your work, ordinarily your WPS would be qualified for 2T in accordance with QW-450 but I would definately double check the constructing code before making that assumption!