By 803056 
Date 09-04-2011 16:39
Edited 09-07-2011 15:40
It is important not to confuse or mix the requirements of Clause 4 parts B and C together just as it is important to not confuse or mix the requirements of ASME Section IX Articles 2 with Article 3. AWS D1.1-2010, Clause 4 Part B (includes clause 4.8) addresses how a WPS is qualified by testing. Part C addresses how a welder is qualified. So, if you are qualifying a welding procedure because it does not meet all the requirements of Clause 3, the information required, such as the essential variables, are found in Part B. That you already know, but there are others reading the post that may not be as familiar with D1.1 as you are.
You noted that the single V-groove with backing using a 60 degree groove angle isn't prequalified if the writer fails to take advantage of the "As Detailed" and "As Fit-up" tolerances of Figure 3.4. If the person writing the prequalified WPS does include the "As Detailed" and "As Fit-up" tolerances, the groove detail is considered to be prequalified provided all the other essential variables are met, in which case there is no need to visit Part B of Clause 4.
If a prequalified WPS is written to address the joint details required by AWS D1.1 Part C of Clause 4 it can be very specific and does not have to include every joint detail included in figures 3.3 or 3.4, nor should it. The prequalified WPS written for the purpose of performance qualification would be used for fillet break weld tests and single V-groove plate tests with backing. Any test for open root tubular joints such as the T, Y, and K test would require a qualified WPS supported by a PQR.
I take the position that a WPS listing all the joint details depicted by AWS D1.1 Figures 3.3 and 3.4 should not be used for the purpose of performance qualification. It is my contention that the WPS used for performance qualification should be limited in scope and it should include the appropriate sketches, i.e., Figures 4.21, 4.22, 4.24, 4.27, 4.28, 4.29, 4.30, 4.31, 4.32, 4.37, 4.38, and/or 4.39, for the performance test being administered. To make reference to a weld detail, i.e., joint detail that is not applicable to performance testing is misleading the welder being tested. If someone were to provide me with a WPS that listed all the joint details included in Figures 3.3 and 3.4 it would lead me to believe I could use any of the joint details listed with the attending tolerances for the performance test. As you noted, many of the joint details used for welder qualification are not prequalified when only the nominal and “As Fit-up” dimensions are listed. Only when the “As Detailed” dimensions are utilized is the joint detail prequalified. The “As Detailed” is applicable only when the designer invokes them. Clarity should be one of the goals for the individual writing the WPS and it should be a goal when providing direction to the welder taking the performance test. AWS D1.1 Clause 4.19 makes it pretty clear that only the tests described by Part C are to be used for welder performance qualification. The specific tests required are detailed in Clause 4.21.
Best regards - Al
I think the problem is that most code users would expect that the D1.1 code would provide performance test parameters within prequalified limits. I do not think that is the case. The prequalified joint details are in the code to guide the user to optimal range of joint details, or the easiest range. Now a performance test may not want to use parameters within the easiest range. The code may want to test welders to variables a little tougher then they would normally see. Or it may be forcing the deposition of more beads in a multi-pass weld, something you would not prefer to do in a production weld. Therefore, the performance variables may push you outside of preferred (prequalified) joint details. In that case you need to qualify a procedure to cover your welder test.
That is the way I see it. I am not saying I am right, but it makes the most sense to me.
