AWS D1.1 ambiguity in qualification of WPS and welder

Date 03-20-2017 09:12 Edited 03-21-2017 06:45

Dear All,

I need to use AWS D1.1 - 2000 'Structural welding code'. I kindly request you to help me understand qualification of WPS and Welder:

1. Shall pre-qualified WPS to be used for welder qualification purpose be mandatory approved by customer / engineer ? Engineer or customer representative has not yet been decided for the contract. I want to qualify a few welders using prequalified WPS. Currently, no engineer / customer representative is there to approve it.May I qualify welders using well written prequalified WPS wihich has not been approved by the engineer yet? May I qualify welders using the same and later I make it approved?

2. In AWS D1.1 - 2000 Table 4.5 titled as ' PQR Essential Variable Changes Requiring WPS Requalification for SMAW, SAW, GMAW, FCAW and GTAW. ', I want to resolve my ambiguity regarding following problems. As mentioned in the table " A change in current in the amperage for each diameter used by : 10 %'" is an essential variable. " So, how is this variable applied if I have used a range of amperage current to fill the groove of the qualification test coupon ? For example, if, in the test coupon, I have used 170A for 1st pass, 200A for 2 nd pass and 150A for 3rd pass. Now, what amperage range may I mention in the WPS???

150 -+ 10% = 135 A / 165 A, 170 -+ 10% = 153 A / 187 A & 200-+10% = 180 A / 220 A

So, may I mention a current range in amperage as 145 A to 220 A for all the passes in the WPS? or should I mention like ' for 1st pass 145 A to 165 A; for 2nd pass 153 A to 187 A and for 3rd pass 180A to 220A?

By Mayur

Date 03-20-2017 12:47

Experts, please, reply and help.

By welderbrent (*****)

Date 03-20-2017 21:29

First, why would you want to qualify your welders to a 17 year old code? Even if the work to be done required usage of D1.1:2000 (which I find peculiar) you can and should still qualify your welders to D1.1:2015. As to the work being done it won't matter to weld to an older code but don't qualify your welders to the older code.

Second, if you are qualifying in house or using an independent lab for welder quals you do not need the engineer's approval until such time as you submit your welders for their approval and usually all they want to know is that they are qualified to the correct code, D1.1 in this case, and that they are current meaning they have used the process within each 6 month period since the original qualification date.

Third, the WPS used for welder qualification should be written based upon the Tables and Figures used in Clause 4 for Welder Performance Qualification. Generally a V Groove with backing and appropriate dimensions of root opening, bevel angle, etc.

Now, what are you using the PQR Essential Variables for? If you are using a Prequalified WPS for the WPQR and hopefully for production as well, why are you trying to figure out your amperage range?

He Is In Control, Have a Great Day, Brent

By Mayur

Date 03-21-2017 04:26 Edited 03-21-2017 06:45

Thank you very much , Sir for your helpful response.

My second (2.) question was separate from question one (1. ). My first question was for welder qualification and second was for procedure qualification.

Actually, the details of the production joint, I have to weld do not conform to the details of the groove for prequalification of WPS. Details of my production joint is 10 mm root face, 1 mm root gap and 60° groove angle and thickness of the plates to be welded is 21 mm. So, for this weld joint, I need to qualify the WPS by performing all the test of PQR qualification. So, what current range may I mention in the WPS, if I have used a range of current while performing a PQR i.e. I have used 170A for 1st pass, 200A for 2 nd pass and 150A for 3rd pass. Now, what amperage range may I mention in the WPS???

150 -+ 10% = 135 A / 165 A, 170 -+ 10% = 153 A / 187 A & 200-+10% = 180 A / 220 A

So, may I mention a current range in amperage as 145 A to 220 A for all the passes in the WPS? or should I mention like ' for 1st pass 145 A to 165 A; for 2nd pass 153 A to 187 A and for 3rd pass 180A to 220A?

By 803056

Date 03-20-2017 23:30

As noted by Brent, qualify your welders to the most recent edition of AWS D1.1 using a prequalified WPS. You can write the prequalified WPS if you understand what it must address and what information must be included. In your case, it would make sense to write a prequalified WPS specifically for welder qualification.

Clause 3 addresses the prequalified WPS. The prequalified WPS must utilize one of the prequalified welding processes, one of the listed base metals, one of the joint details listed in clause 4 for welder qualification, etc. DO NOT use a prequalified joint detail included in clause 3 because the tolerances are not appropriate for welder qualification. All of the variables included in Table 3.6 and Table 3.7 must be addressed. If necessary, you could write two WPS to extend the range of welding variables needed to weld the root, intermediate, and cover layers. To be honest, there should not be any need to use such a wide range of wire feed speed, voltage, and amperage for a welder qualification that employs a backing bar.

Best regards - Al

By Mayur

Date 03-21-2017 04:42 Edited 03-21-2017 06:45

Thank you Sir for your helping response.

1.) For procedure qualification. Actually, the details of the production joint, I have to weld do not conform to the details of the groove for prequalification of WPS. Details of my production joint is 10 mm root face, 1 mm root gap and 60° groove angle and thickness of the plates to be welded is 21 mm. So, for this weld joint, I need to qualify the WPS by performing all the test of PQR qualification. So, what current range may I mention in the WPS, if I have used a range of current while performing a PQR i.e. I have used 170A for 1st pass, 200A for 2 nd pass and 150A for 3rd pass. Now, what amperage range may I mention in the WPS???

150 -+ 10% = 135 A / 165 A, 170 -+ 10% = 153 A / 187 A & 200-+10% = 180 A / 220 A

So, may I mention a current range in amperage as 145 A to 220 A for all the passes in the WPS? or should I mention like ' for 1st pass 145 A to 165 A; for 2nd pass 153 A to 187 A and for 3rd pass 180A to 220A?

2.) For welder Qualification. Engineer / Customer representative has not been decided yet for the contract. This contract needs the qualification as per AWS D1.1 . For this contract, I need to qualify the welders. I have written a prequalified WPS for the welder qualification purpose, but it has not been approved by Engineer / customer representative as engineer / customer representative has not been decided yet. So, may I qualify welders using this written prequalified WPS which has not been approved by engineer? May I qualify welders using this now and later I ask for engineer's aprroval, is it ok?

Thanks and Regards,
Mayur

By 803056

Date 03-21-2017 12:16

The usual course of events here in the US is for the Owner to select a fabricator/contractor to do the required work. The Owner is responsible for specifying the appropriate welding standard and then the contractor/fabricator does what he must to comply.

If you are qualifying the WPS by testing, you are not bound by the conditions of prequalification. You record what is actually done to qualify the WPS, i.e., record the welding parameters for each weld bead, etc. You WPS for production would be based on the parameters used to weld the test plate.

Usually, the customer only reviews the welder qualifications to verify they were done properly.

Al