WPS Qualification Requirement

Unless you are lucky enough to be able to find "pre-qualified" joints in AWS or CWB (or other standard), which I doubt in this case, you will need a WPS for each joint made as each condition is different. You are working to some codes, and I cannot see anyway around it. I might be wrong, but my experience tells me otherwise.

That's correct........ develop the WPS with the type of joints you require...... any additional joints in the future you may require. you can always append your WPS.

Both of us have no clue how to proceed.

That is fine for me, as I am not paid to qualify a welding process.

You, on the other hand, are paid to do this.

How will you justify your qualification rational?

A. "I guessed it'd be OK"?

B. "If it doesn't blow up, does it matter"?

C. "I got input from from my new friends at CR4"?

D. LynDoor™Industries Most Excellent® Welding specialists said to go for it and approved the WPS for me"?

If you choose D, let me know.

If you do, here's your stamp:

Pick one.

What is your welding process to execute this job? Process is very important as some welding processes have limitation on base metal thickness range as per ASME BPVC Section-IX.

Welding Process is SMAW, Manual method.

Joint type: Single-V, Double-V with backing and fillet for bottom plate welding(lap joint).

Specified electrodes: 6010/3.2mm for the root & E7016-1H4R for others layers.

My problem are as follows:

1) My boss said we should use this WPS to weld all materials thicknesses for the tank. Is that ok for me to accept professionally?

As per ASME BPVC Sec-IX, QW 403.6, the qualified base metal thickness lower range is 16mm.Higher thickness range is 2t (ie, 36mm) as the base metal PQR coupon thickness is less than 19mm. As per ASME BPVC Section-IX, If you want to weld 10mm plate, you have to qualify another welding procedure to cover lower limit of the base metal (ie, 10mm). However, your boss is your supervisor and in a business environment it is not a good practice to devalue your boss's orders. Convince him about code requirement and proceed as per your Boss's final decision as he is your BOSS.

2) i want to know the range of P.No qualified; &

Your PQR coupon falls on P1 G.1.So, your qualified base metal P No range also only P1 as the P number is an essential variable. When notch toughness is a requirement, supplementary essential variable (in this case Group Number) will become an essential variable. So, your base metal qualified range is P1.Gr.1. In case, if you have any flange material with P1Gr.2 to weld P1 Gr1 material in the project, then it is better to qualify the welding procedure with P1Gr1 and P1Gr2 material. This will qualify P1Gr1 to P1Gr1, P1Gr1 to P1Gr2, and P1Gr2 to P1Gr2

3) Group number is a supplementary essential variable; how do i address/ or specify this in the wps based impact limitation?

You can find WPS format in Non mandatory Appendix-B of ASME BPVC Section-IX. In that format, you can find appropriate space for base metal range qualified. You can clearly show the limitation on that column by providing ONLY the qualified range of P.No and Gr.No

Hope this helps.

Guys, your input will be of great help to me. Thanks to all.

Thank you for your time and thank you for your interest to select this forum to ask your query.

(i)If you qualify a WPS for base material thickness of 19mm to 38 mm , the procedure gets qualified for base metal thickness of 5 mm to 2T. So , one WPS may cover from 10mm to 25mm as per QW 451.1.

(ii)If you qualify WPS with P no 1 material, the procedure gets automatically qualified for P no 1 to P no 15F material as per ASME section IX QW 423.1and QW 424.1.

(iii)The excerpt form ASME section IX QW 403.5 is given below for group no qualification.

For ferrous materials in table QW/QB-422, a procedure
qualification shall be made for each P-Number Group Number
combination of base metals, even though procedure
qualification tests have been made for each of the two
base metals welded to itself. If, however, two or more
qualification records have the same essential and supplementary
essential variables, except that the base metals
are assigned to different Group Numbers within the same
P-Number, then the combination of base metals is also
qualified. In addition, when base metals of two different
P-Number Group Number combinations are qualified using
a single test coupon, that coupon qualifies the welding of
those two P-Number Group Numbers to themselves as well
as to each other using the variables qualified.

Thanks for much information provided by your comments. The thickness range you specified is OK when impact test is not required by Code. But my WPS is impact tested and the test coupon is 18mm thick and the thickness range is 16mm to 36mm, while production materials includes 10mm. What do i do to weld 10mm base materials on the project? Should i qualify another WPS on 10mm plate with impact test again?

your boss may be correct. Check your applicable code. generally mthickness below 16 mm is exepted from impact requirement. atleast ASME says this. so when your production weld is 10 mm, it does not have impact requirement. so for this joint your qualification is valid for the thickness range 5 mm to 36 mm. Hope you got the point.