Tuesday, March 20, 2012

Qualified per Clause 3? or Clause 4?

I'm working with company that has their Welders certified on A36 plate with .045 solid wire. They have taken the test with GMAW, in a vertical down progression, in a globular transfer. They took it on 1 inch plate, Single V- Groove with backing. The company they want to do work for wants them qualified to do flat and horizontal fillet joints but says they are not qualified because they welded there test plates vertical down.
Who's right?
Loren H.

“Who’s right?”  My first reaction would be, "The Customer", but we're Inspectors so we’ll dig a little deeper then that.   For the sake of this question I’m going to assume the qualification we’re discussing is to AWS-D1.1.
When the Welders were tested they needed to be tested to a qualified weld procedure specification (WPS). They could not have taken the test using a prequalified procedure because a prequalified procedure would require a vertical up progression (See AWS-D1.1-2010, Clause/Sub-section 3.7.1). So the company you are working with must have on file a Procedure Qualification Record (PQR) for welding groove welds in the vertical position with a downward progression.
Often, I’ll audit small fabrication shops for compliance to AWS codes and standards.  Welding to a Prequalified WPS that does not fit within the guidelines of Clause 3 is something I come across all too often.  The 3 big hitters I find are:
#1) welding materials not found in Table 3.1,
#2) welding vertically in a downward progression and
#3) not staying within the preheat/interpass requirements of Table 3.2.
So, long story short, if the company has written weld procedures for the Flat and Horizontal positions and has qualified the Vertical down progression, then Welders tested 3G down to a qualified procedure would be considered qualified (within the restrictions of Table 4.10).
It has been my experience that it's pretty tough to qualify a multi-pass procedure 3G down. Not to say it can't be done. I've just struggled with it.
Let me know if the procedure was qualified… That’s kind of a big deal.
Thanks for writing.

Loren Replied:
Thank you for your response.  Believe me you haven’t heard the last of me.  I’ve been looking for someone to answer my questions , and I usually have a lot of them.  Unfortunatly  I’ve made a mistake thinking you could weld GMAW down and it would be prequalified. I’ve contacted the company and explained the problem.  I have a date to retest them either vertical up or just doing fillet joints which is all they need anyway. I guess it’s one of life’s lessons. I should read more and not listen to others.