Electrode diameter change

By SWN1158 (***)

Date 01-11-2019 21:58 Edited 01-12-2019 17:27

We have welders testing for the D1.8 Supplemental Welder Qualification for Restricted Access Welding. The question has come up if we can weld the root pass with a 1/8 diameter rod, and all subsequent passes with a larger 5/32 diameter rod to complete the joint.

D1.8 references Table 4.12 Welding Personnel Performance Essential Variables Changes Requiring Requalification. Item (4) states "to a diameter or thickness not qualified". My interpretation is that if we qualify the welder using 1/8 at the root, and then change over to a 5/32 rod to fill the restricted access joint during the welder qualification, we will satisfy the requirement of item (4). Is this your understanding as well? We would also need to include this in our WPS.

By Lawrence (*****)

Date 01-12-2019 05:27

I don’t have my code book on hand.

But please review the table to see if “diameter and thickness” might be speaking to base metal rather than electrodes.

By SWN1158 (***)

Date 01-12-2019 09:04

I didn't even think about that possibility because I had electrode diameter on my mind, but you're correct... that it's referring to material diameter, i.e., pipe, which has limitations on welder qualification.

I know that a change in electrode diameter by > 1/32 is a PQR essential variable that would require a requalification of the WPS, but even if we were doing a PQR, that still wouldn't come into play, because the electrode diameter we're using for subsequent passes is a 1/32 increase.

This is something I've never had to deal with... using two different electrode diameters within the same joint, and I simply had electrode diameter on the brain. Thank you Lawrence! You da man!!!!!!!!!!!