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Up Topic American Welding Society Services / Technical Standards & Publications / D1.1 PQR with Multiple Processes
- - By TexasWelds Date 09-11-2013 15:31
I spend most of my time in ASME codes and delineating between weld metal deposited and base metal thickness is clearly defined. With D1.1 this is not so.
If I have a PQR with multiple processes, lets say 1/2" of SMAW and 1/2" of FCAW filler metal on a 1" plate, what thickness are each of these processes qualified for?
ASME would say 2t (where t is the deposited weld metal thickness), this is not defined anywhere within D1.1 that I can find.
Parent - - By jwright650 (*****) Date 09-11-2013 15:43
I don't have time at the moment to dig into this real deep right now...but try reviewing Table 4.2 D1.1:2010, I believe this Table has the qualification ranges listed for different thickness tested and what thicknes are qualified....I'll look back at this when I get a few minutes and elaborate further.

Also Table 4.5 lists the essential variables that require requalification of the PQR.
Parent - By TexasWelds Date 09-11-2013 15:55
Table 4.2 specifcally states "nominal plate thickness tested" and "nominal plate, pipe or tube thickness qualified" with no regard to deposited weld thickness.
Table 4.5 also does not address deposited weld thickness.
I appreciate any insight.
- - By 803056 (*****) Date 09-11-2013 16:34 Edited 09-11-2013 16:36
AWS D1.1 does not have provisions for qualifying multiple processes on the same test plate.

Once the processes are qualified, AWS allows you to mix and match them as necessary to meet production requirements. However, keep in mind that each process must be qualified for the full thickness of the production joint, in other words, the thickness for production needs is not the sum of the individual WPSs used.

Best regards - Al
Parent - - By jwright650 (*****) Date 09-11-2013 16:45
I believe Al is correct, I looked briefly through the code and commentary and couldn't find anything regarding qualification ranges for a specific deposited thickness using more than one process in the same test.(for WPS or Personnel)

Al, what about dillution and mixing the different filler materials in the same joint....should he also provide an all weld metal tension test, and a couple bend tests, using both processes to provide proof that the resultant weld will have sufficient mechanicals?
Parent - - By 803056 (*****) Date 09-11-2013 17:30
The post references D1.1, so the base metals are not considered dissimilar and the filler metals are assumed to be compatible.

There are situations where the manufacturer may have additional recommendations, such as which SMAW electrodes should be used for tack welds if the weld is to be completed using FCAW or SAW, but those are not code requirements.

AWS D1.1/D1.1M:2010, clause 3.6.1 states the WPSs can be combined, provided the essential variables are not exceeded, without qualification of the combination. In response to the need to do all-weld metal tensile testing, etc., there is no such requirement unless the contractor is qualifying the filler metal per cause 4.12.3.

Just because the code does not require additional testing does not prevent the manufacturer from doing so to protect their self interest.

Best regards - Al
Parent - - By jwright650 (*****) Date 09-11-2013 17:43
So with what you said, the OP should consider these to be prequalified(as long as essential variables are met for the pre-qual status).

Weld out one 1" plate with SMAW to qualify the welder 1/8" to unlimited with SMAW, and another 1" plate with FCAW to qualify the welder 1/8" to unlimited with FCAW and call it a day. Then that welder could weld the 2.5" plate out using a mixture of both processes in production.
Parent - - By TexasWelds Date 09-11-2013 17:57
welding 2 1" PQR plates is cost prohibitive and time sensitive however, just to qualify the welder, the WPQ tests are much smaller.
Parent - By jwright650 (*****) Date 09-11-2013 18:02
yes, if the welder is already qualified then what I stated about welder qualification is a mute point.

I qualify welders all of the time in-house, it's not too terribly time sensitive to weld out the coupons, saw them up and bend the coupons onsite.
Parent - By TexasWelds Date 09-11-2013 17:55
This said, now I have an understanding and perspective that I can take to a client and defend in the absence of coder language to support. Thanks for the help.
Parent - By TexasWelds Date 09-11-2013 17:17
Thanks, but I am not sure I understand: "However, keep in mind that each process must be qualified for the full thickness of the production joint, in other words, the thickness for production needs is not the sum of the individual WPSs used."
Lets try a couple scenarios, if I have a WPS based on a PQR that was 1" thick with 1/4" of SMAW and 3/4" of FCAW deposited and in production I need to weld a 2-1/4" plate:

Scenario 1: It is welded with 3/32" thick SMAW stringer and filled and capped with FCAW (2-1/32")
Scenario 2: It is completely welded out with FCAW 2-1/2" thick.
Scenario 3: It is completely welded out with SMAW 2-1/2" thick.

All three of the above scenarios seem to meet code as it is silent as to deposited weld metal thickness and combination of processes in qualified WPSs but Scenario 3 does not pass gut check with me. If you can please explain "each process must be qualified for the full thickness of the production joint" because D1.1 does not necessarily address it in the code or commentary. Is it just applied through experience?
- - By 803056 (*****) Date 09-11-2013 17:56 Edited 09-11-2013 18:10
Forget everything known about ASME, API, or military welding standards. The contractor is now working to AWS D1.1. Each welding standard has unique requirements that may be in direct conflict with different standards. Working with welding standards is not akin to Horticulture 401 where one can take a piece of plant "A" and graft it on to plant "B" to get the best of both plants. Nor do the welding standards allow for cross-pollination. Don't take this as an insult to one’s intelligence, it is simply an analogy.

AWS D1.1/D1.1M:2010 recognizes three methods of qualifying the WPS. The most frequent method is prequalification, next, purchasing an SWPS from AWS or qualifying the WPS by testing.

If the contractor play his cards properly, all the requirements for prequalification are met and all the potential problems go up the chimney. Thickness is not a concern unless the base metal is less than an 1/8 inch thick and if that is the case there is a low probability there would need to use more than one welding process. The contractor can mix and match WPSs at will if they are prequalified.

If the contractor qualifies the WPSs by testing in accordance with clause 4, each WPS must be qualified for the full thickness of the production joint. The thickness of the weld deposit is not an essential variable, so file that away for when ASME is invoked by the customer. It isn’t complicated, unless one tries to mix welding standards and then all Hell breaks loose.

The scenario provided where both SMAW and FCAW are used to weld a single qualification assembly is dead in the water. That approach is permitted by ASME, but not AWS. Do not pass "Go", do not collect $200. The WPS noted was qualified per ASME Section IX and is not valid for work required to meet AWS D1.1.

The big question is, "What is it about the WPS that doesn't meet the prerequisites of prequalification?" Perhaps it would be advantageous to review the prequalification requirements of D1.1 and write a WPS that is prequalified. Problems solved.

The problem is trying to use an ASME qualified WPS for an AWS application. That is like mixing oil and water.

Best regards - Al
Parent - - By Lawrence (*****) Date 09-11-2013 18:37
D1.1  2010

4.2.1.2

Just throwin it out there.
Parent - - By jwright650 (*****) Date 09-11-2013 18:40
True, the Engineer of Record has the final authority and can accept qualifications done to other standards.
Parent - By 803056 (*****) Date 09-11-2013 19:10 Edited 09-11-2013 19:21
The point is worth considering. Clause 4.2.1.2 gives the Engineer the authority to consider qualification to other standards. However, was that part of the initial question?

Al
Parent - - By welderbrent (*****) Date 09-11-2013 19:11
There is one more consideration.  I haven't checked to see if it is contained in the Manufacturer's Specs as was already suggested for tacks to be covered be other processes. 

Here goes, FCAW-S (self-shielded) does not play well with others.  While this is not specifically dealt with in D1.1 it needs attention. 

It is however handled in the Seismic Supplement, D1.8, and is prohibited to be used when mixed with others.  At least without PQR's and all the associated testing. 

But, as D1.8 does address it, and, anyone who has done it recognizes the problems, it would be well worth one's time to check out the manufacturer's recommendations on this before just jumping in.  If, that is, you will be using this as one of your processes. 

Otherwise, just ignore me.  Most people do.  :roll:

Have a Great Day,  Brent
Parent - - By 803056 (*****) Date 09-11-2013 19:23
Mixing codes again, huh?

Al :eek:
Parent - - By welderbrent (*****) Date 09-11-2013 22:26
I know. And though I hesitated I thought it worth mentioning. 

Have a Great Day,  Brent
Parent - By 803056 (*****) Date 09-12-2013 01:56
Fodder for the furnace my friend.

Al
Parent - - By ctacker (****) Date 09-12-2013 05:17
Isn't the purpose of qualifying a PQR to see if your proposed WPS will hold up to intended service requirements? Why not qualify a procedure using 2 processes as the OP has inquired about, as long as the EOR is on board. Chances are he would want the as welded (production weld) weld tested rather than testing 2 separate processes and combining them with no testing on the final production weld.
I know D1.1 is quiet on it, but the EOR has the final say. Ask him.
Parent - By 803056 (*****) Date 09-12-2013 13:31
I guess the issue is, "What does the code require?"

The contractor can always approach the Engineer with special applications, but that qualified WPS (using more than one process) may not be useful on future projects and different engineers a different opinions.

The time and money spent qualifying WPSs is no minor expenditure. My philosophy is to meet the code requirements so the WPS can be used on future work. 

As the Engineer, I would go back to my previous position and question why the WPS wasn't prequalified. I would look at this situation with a jaded eye and question whether the contractor actually understood the requirements of D1.1. If I had doubts, I would amp up the level of oversight and consider whether that is the right contractor to be fabricating my steel. I use the contractor's documentation to gage how competent they are from a technical standpoint and their competence with D1.1. If their documentation is technically deficient there is reason to ask additional questions.

Al
- - By StaffanC Date 10-05-2013 04:30
Dear all,

Quite interesting to read about this difference between ASME IX and AWS D1.1 and multi process PQRs not allowed in AWS D1.1

Let us focus on AWS D1.1 and its Chapter 4, Qualification, for my below questions (leave pre-qualified WPSs out of this).

Suppose I qualify 3 PQRs. One for GTAW, another for SMAW and a third one for the FCAW of  10 mm thick CJP butt weld. In other Words, I have qualified three different welding processes for the welding of 10 mm thick steel plate. 

What would be the maximum allowable plate thickness to be welded in production using:

a) SMAW (used on a CJP-butt weld) ?

b) GTAW + SMAW  (any two of the qualified methods,  used together on a CJP-butt weld) ?

c) SMAW + GTAW + FCAW (all three methods, used together on a CJP-butt weld)?

Looking forward to your input

Kind regards

Staffan Carlsson
Parent - - By 803056 (*****) Date 10-05-2013 19:54
Each process is qualified for 2xT or in this case 20 mm.

The three processes, when combined, are also qualified for the sum total of 2xT or 20 mm. They are not additive.

Al
Parent - - By StaffanC Date 10-09-2013 05:00
Many thanks,

Cheers

Staffan
Parent - - By Kos Date 07-18-2015 12:23
Hi Everyone, this is my first post.

I use European codes most of the time and I am struggling to find something in AWS regarding multi process welding.

Basically, in BS EN 287, if a welder is qualified on a BW say processes 1 GTAW root hot pass process 2 SMAW fill and cap. The range of the welders approval in BS EN 287 qualifies him to weld process 2 without process 1 on fillet welds, butt welds with backing and butt welds welded from both sides, but not single sided welding without backing.

Does AWS allow this? And if it does or does not could you please give me the AWS reference No?

We are working to EEUMA 158, and this code refers me to BS EN 287 & AWS D1.1.

Any advice will be greatly appreciated!

Markos
Parent - By Golden Arm (*) Date 08-13-2015 19:02
It being common practice throughout all industries to use more than one process to complete a weld and multiple codes allow qualification of PQRs and WPSs using a combination of processes why is AWS not onboard with the practice? PQRs and WPSs and qualifying welders on multiple coupons just to be able to make welds using multiple processes is prohibitive.
Parent - By bbernard Date 08-13-2015 19:21
From The Official Book of D1.1 Interpretations 1976-2008:
Qualification of Multiple Welding Processes
Dl.1-90
Subsection 5.5
1-9/91-10-03

Inquiry
(1) Can one or more welding processes be deleted from a qualified welding procedure in accordance
with AWS Dl.l, subsection 5.5, if each of the essential variables for each of the remaining
processes is maintained?
(2) Based on a qualified welding procedure involving a GMA W root pass, SMAW backweld, and
SAW fill and cap passes; [can this WPS I be separated into its component parts to qualify other
WPSs, as shown in the Inquiry letter?

Interpretation
(1) No.
(2) No, the acceptance or rejection of specific WPSs is beyond the authority of the D l Committee.

Here is a link: https://app.aws.org/technical/interps/i-9-91-10-03.pdf
Up Topic American Welding Society Services / Technical Standards & Publications / D1.1 PQR with Multiple Processes

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