Case 1:
"Procedure A is qualified using GTAW for open root grooves on pipe in the 6G position using A106 pipe. Procedure B is qualified using SMAW on pipe with backing in the 6G position using A53 pipe. The parameters and test results are documented as PQR A and PQR B respectively.
WPS AB is written to use GTAW for the open root and second layer. The fill and cover are to be deposited using SMAW. WPS AB is supported by PQR A and PQR B. Perfectly legitimate and it is common practice for mechanical piping.
Are you suggesting that there should be two separate WPSs of the application noted above or that it isn't permitted?"
To me that's combining two WPSs in one joint, but that distinction doesn't really matter; I may be wrong in my terminology. In this case, you're using PQR A, in its entirety, for the open root and second layer, in their entirety. Likewise for PQR B and the fill and cover. Each type of pass is independently qualified by its own PQR. You're not taking bits and pieces of PQRs A and B and mixing them together to create an entirely different type of pass from what was tested in either PQR. So if your WPS adequately indicates that *this* PQR qualifies *these* passes and *this* PQR qualifies *these* passes, I'm fine. If your WPS doesn't distinguish between the first two passes and the rest, and just says "weld this joint with SMAW or GTAW, based on PQRs A and B", then you have a problem. If your choice of how to document your procedure captures what needs to be captured in order to make the distinction, then you have no problem. I don't care how many pieces of paper you use or how many numbers you assign to it as long as you separate what needs to be separated in some way. But I am in agreement with you that, assuming it's written to convey what needs to be conveyed, that this should be allowed.
Case 2:
"Another scenario: Aluminum alloys welded with GTAW using a common filler metal 4043. The first successful test is documented as PQR C using GTAW, Argon, ER4043 filler metal, 6061-T6 base metal using a bevel groove. The second test is documented as PQR D using GTAW, Argon, ER4043, using 5052 base metal with a double V-groove. All the tests are acceptable, the differences between the two being the groove type and the M number of the base metals. Both PQRs are used to support one WPS listing all M22 and M23 base metals and all the groove details depicted in AWS D1.2.
Once again, I ask you, this is not acceptable?"
Again, I think what you really have there is two WPSs combined on one piece of paper, but that's not really what this discussion is about.
If the *only* difference is the base metal and the groove, not a problem. You're not mixing and matching because everything else is the same and there's nothing to mix. If, however, you had a particularly low-heat set of parameters on PQR C and a high-heat set of parameters for PQR D, do you think you've adequately demonstrated that the low heat of PQR C will work for welding the type of base metal you used for PQR D? I don't know the answer to that; I don't deal with aluminum. But for steel, if you used a low-heat procedure on one type of base metal or filler metal and then high-heat procedure on a completely different type of base metal or filler metal, there's nothing there to tell me that the low heat would have worked on both. That's the whole point of Table 4.5. "You did X in the test. There's only so far away from X you can go for that test to still be relevant. If you deviate enough from the test, that test no longer represents what you plan to do in production and you need to show me another test."
Case 3:
"My last example: Procedure E is 3/32 inch thick carbon steel plate welded in the flat position with 3/32 E7018 at 23V, 90 amps, 4 ipm. Procedure F is carbon steel plate is 3/8 inch thick welded in the flat position using 5/32 E7018 at 27V, 8 ipm, and 180 amps. Both are documented as PQR E and F respectively. The fabricator elects to write the WPS for 3/32 inch to 3/4 inch using 3/32 to 3/16 electrode with the ranges of 22V to 29V, 70 to 285 amps, 3 to 10 ipm listed.
Are you saying that he can't do that?"
Yes, I'm saying he can't do that. To weld 3/4" plate with 3/32" electrode he's pulling the plate qualification from PQR F and the electrode diameter from PQR E. He's done nothing to demonstrate that that combination ought to work (assuming qualification testing actually has merit and that it's not the case that pretty much anything will work with anything). That's every bit as logical as pulling his base metal (brass) off PQR E and his filler metal (titanium) off PQR F. Okay, I exaggerate, but that's what you get when you follow the "one from column A and one from column B" approach to its extreme.
To me, Table 4.5 says that if you've run a test, here's how far away from that test you can go. There's nothing in the code that says you can run a separate test to qualify each essential variable independently and to me that is a terrible misapplication of the code's intent.
And, of course, every word I've ever typed on this forum, short of direct quotations from documents, is only my opinion. My opinion only counts if you're trying to get me to approve something.
Hg
You are running afoul of ASME Section IX because the parameters you are concerned with are nonessential variables. They can be changed without supporting evidence of a PQR.
I am not disagreeing with your thought process from a welder's view point, but strictly speaking as a "code guardian" your argument would hold no water if the applicable code is ASME Section IX.
Heat input only plays a major roll when notch toughness is a concern. Whether you elect to weld heavy plate with small diameter electrodes or large electrode as is the case with PQR C and D is of little concern. It will take longer with small rods. It will require more weld passes with small rods, but the number of passes has little influence on the mechanical properties such as tensile strength or ductility. As long as the two PQRs used base metals having the same P, M, or S number (it did, both SA105 and SA106 are P1), it is perfectly legitimate to combine the PQRs into one WPS. It is standard practice for many applications.
I understand where you are coming from and I am usually on the same side of the fence you are, but there is a difference between meeting code requirements and meeting the customer's needs. As a consultant you have to be aware of both. As a TPI reviewing the welding documentation package you have to keep your personal opinions to yourself and do the review based on what is and what is not acceptable per the applicable code. When you interject your personal opinion into the process you have made yourself a consultant instead of a TPI.
I am going to admit that I screwed up on the aluminum procedure, I forgot to include a PQR for 5052 to 6061 with ER4043 filler metal and 5052 to 6061 using ER5356 filler metal to make the combination legitimate. So, one WPS supported by six PQRs. Its all a part of my reduction in paperwork enspoused by the US Government. You've seen the statement I'm refering to on all the IRS forms. Back on subject, with the six PQRs I can weld 6061 to 6061, or 6061 to 5052, or 5052 to 5052 with either ER4043 or 5356, all with just one WPS. For this exercise I would use a tabular format to describe the combinations. The variations and permutations are endless! Ah ha ha ha! (mad evil laughter)
Best regards - Al
I assumed we were talking about D1 codes, this being the "D1 Questions" board. I've never dealt with ASME Section IX and don't know what its requirements are.
It still doesn't make any sense to qualify each line of the D1.1 Table 4.5 essential variables with a completely independent test. In my opinon, of course.
Hg
By 803056
Date 02-05-2010 21:33
Edited 02-05-2010 21:39
Many of the comments are valid for D1.2 as well as B2.1 or ASME Section IX.
I now return to Stephen's original question and I still say the response is yes. He has supporting PQRs that allow him to weld in multiple positions and the ranges are a compilation of the ranges used when qualifying the individual PQRs.
I like Johns approach to separate the positions and list the parameters based on the applicable PQRs, but there is nothing that says I have to do it that way.
As a matter of fact, I typically write a WPS for welder performance qualification with very wide ranges to see what parameters work the best. Then I revise the production WPS by narrowing the range for the parameters to reflect the lessons learned while qualifying the welders.
Best regards - Al