WPS Help

Date 05-16-2009 15:50

Dave,

Not sure if this is a plate, or pipe application.

Check joint design B-U2-GF, to see if that will help. It is on page 92, in the AWS D1.1:2006 edition.

You might just have to revise the WPS.

By david bean (**)

Date 05-16-2009 17:34 Edited 05-16-2009 17:49

motgor,
This is a wide flange I- beam I think this might work because (f) is 0" to 1/8". In this case it would be zero. And they did backgouge. I really appreciate the feedback, i will do some checking, but this should work. What about the backing situation. The guys used a backing , then removed it to backgouge.

Regards
David J Bean

By motgar

Date 05-16-2009 21:54 Edited 05-16-2009 22:10

Dave,

There maybe a problem with that then.

Are the welders themselves qualified to run joints without backing? Table 4.12 number (6) states: If the welder took the WPQR with backing, then omitting it now requires the welder to be requalified. I am still referring to AWS D1.1:2006. Table 4.12 is on page 150.

One last thing when you referred to note (e) for the pre qualifed figures. Please note the word "may." Take a look at Section 1.3.6.3. I figure you have the text so, I will not write it verbatim.

By david bean (**)

Date 05-18-2009 15:07

The welders are using a backing bar on the farside of the joint. they weld one side then remove the backing bar, backgouge, and complete the weld. Does the WPS need to show the backing bar and would this require Qualification?

By ctacker (****)

Date 05-18-2009 16:11

motgar,
See 4.23 2006 or 2008. A welder qualified with backing is also qualified to weld a joint that is backgouged and welded from the second side.

By swnorris (****)

Date 05-18-2009 16:22

david bean,

In your initial post you mentioned this is a prequalified joint. What is the joint designation? What welding process was used?

By david bean (**)

Date 05-18-2009 17:22

B-U2a-GF, Sigle V Groove prequalified for F,V,OH but not Horizontal. The field guys welded FCAW NR232, this joint on a W12X45 in the horizontal position. The fit-up was approved by the feild inspector so the guys welded out the joints, then that same inspector filed a NCR for those joints and wants to see a weld procedure. IF the joint was prep as a Single Bevel it would fine since this is prequalified.

By motgar

Date 05-18-2009 17:03

Thanks for pointing that out.

Just seems a bit odd to me. Suppose I would like it better being qualified to do what I was actually doing, then say that is good enough.

By jwright650 (*****)

Date 05-18-2009 17:23

I'm not sure I understand the question here....so you have a full pen joint with backing and you weld, remove the backing and then back gouge, reweld.....can it be done?....Yes, Erectors do this all the time at the bottom flange on FEMA (beam to column) moment frames, plus they even add a reinforcing fillet.

Are you asking about the qualification of the Welder or the Procedure?

By jwright650 (*****)

Date 05-18-2009 17:31

Maybe I see your question now that I've read more of the replies......what you have by removing the backing bar is a B-U2-GF, and it IS prequalified in the Horz position if they will overlook the groove angle of 60°....if this gets UT'd and is clean, would they make you cut it out and reweld anyway?

By swnorris (****)

Date 05-18-2009 17:42

I agree with John. If it passes UT, why reject it? After all, passing is the bottom line.

By jwright650 (*****)

Date 05-18-2009 17:58

The wider groove angle is purely for access to the root anyway.....hopefully the welder was able to keep it clean and gouged out any unfused material.

By david bean (**)

Date 05-18-2009 17:41

I just need a Welding procedure, im gonna try submitting B-U2-GF, i think this should work because the root face can be from 0" and is not limited and is prequalified in the all positions. The only thing is the backing bar it is not shown on the B-U2-GF .Will this be an issue? The feild forman says that they are required to use backing bars on all CJP for this job. Im not sure if its in the specs or that just something the site inspectors requiring? it makes sense to me if you have any root opening. But will this WPS work for this situation???

By jwright650 (*****)

Date 05-18-2009 17:56

As for the use of the backing...it can be used just to contain the root so that the molten filler don't fall out the back side.....ie: AWS D1.1 Clause 5.10

By motgar

Date 05-18-2009 18:51

The backing bar not appearing on the drawing and, WPS joint scetch may confuse some that are used to seeing them that way.

In theory, here is what I am thinking:

I think your current joint designation is B-U2a-GF. Assuming that it is utilizing the root opening of 1/4", and included angle of 45 degrees.

If the joint designation B-U2-GF is used, then the root opening will close up to zero. (If that is what you prefer) "That 1/4" lost will need to be made up some where." Keep the root face at 1/8" to 3/16" that way it could still be considered (backing) just in a different way. The parent metal is you backing as opposed to an external, then removed backing. Eliminating that step. Backgouging will still need to be perfomed, and the back weld put in place. Assuming the welder fills the angle side of the root first.

As far as the difference in included angle. B-U2a-GF with 45 degrees, and B-U2-GF with 60 degrees.

B-U2a-GF is given a + 10 degree tolerance. So I see 55 degrees max. B-U2-GF has a - 5 degree tolerance. So I see 55 degrees min. Both are based on the as fit up conditions. Now I know that it is slim to none that these values are going to be exact in the field. In theory 55 degrees look good on paper.

Generally thinking; If the included angle does open up, then more weld metal will need to be deposited. Certainly an increase in the aspect of time. If the steps of attaching/removing the backing are eliminated, then it might either balance or offset that time. Hopefully offset to the good.

I am not too sure how deep the joint is going. I think it would be nicer to have more room to move, then feel confined in a tighter joint. Assuming that there is no nozzle, on you self shielded FCAW gun. Would certainly hate to touch out the contact tip on accident. OOPS. "Clean up in joint 123" : (

Just my thoughts.

By pipewelder_1999 (****)

Date 06-24-2009 16:20

You indicated "...The feild forman says that they are required to use backing bars on all CJP for this job. Im not sure if its in the specs or that just something the site inspectors requiring?..."

Is it possible the requirement is written that all CJP welds shall be welded with backing ?

If that is the case, joints welded from both sides after backgouging are consindered welding with backing. Maybe the requirement that is in the project specifications need to be looked at again just to make sure.

Gerald

By 803056

Date 06-24-2009 19:14

Gerald has it right.

If a CJP joint is welded from both sides and the initial weld is back gouged to sound metal and back welded, it is considered to be welded with backing. I believe it is assumed that includes a proviso the root face is thick enough to prevent excessive melt through when depositing the root bead from the first side.

PJP welds are considered to be welded with backing when assessing welder performance qualifications.

It makes little sense to require the use of backing unless there is insufficient root face to prevent excessive melt through. An exception is when a backing is used with a corner or T-joint and a reinforcing fillet is required on the root side of the joint, in which case the backing must be removed and the reinforcing fillet weld deposited on the root side.

Best regards - Al