Qualification of 2 welders on one piece of pipe - ASME IX

[teokal]

Hi all,
We are currently working on P91 piping (B31.1), and due to the fact that material available for test coupons is extremely limited or would delay lots of weeks to be delivered, we decided to qualify welders from production welds (after the theoretical training), using volumetric NDE. My question is: Can I qualify (separately or together) 2 welders that have welded as a couple on one let's say 24" pipe? QW 302.2 (Section IX) states that the whole circumference shall be welded and tested. Is there any other topic that reliefs me from QW 302.2?
thanks in advance for your replies

Only best result in absolutely necessary time

 

[SJones]

304.1 (a)

Steve Jones
Materials & Corrosion Engineer

http://www.linkedin.com/pub/8/83b/b04

 

[teokal]

Thanks, SJones, but this paragraph refers again to full circumference... Is there any Code Case or anything else that anyone is aware of, that I could use in order to qualify a welder having welded half of the circumference?

Only best result in absolutely necessary time

 

[SJones]

If you read it, it doesn't actually say "the entire circumference of the pipe made by one welder." It says, 'the entire production weld circumference made by the welder.' So, half the pipe circumference would be the entire production weld circumference made by each of the two welders. This is the way it works in pipeline welding, albeit with the number of welders being a WPS variable!

Steve Jones
Materials & Corrosion Engineer

http://www.linkedin.com/pub/8/83b/b04

 

[qcrobert]

I concur with SJones.

Also see QW-452.1(b) for thickness qualified.

 

[Kiwi2671]

Steve / Robert,
ASME IX is quite clear - the welder must weld full circumference.
QW452.1(b) is related to 2 or more welders welding a variety of processes or thickesses in the one joint.

Yes Steve, you are correct, the majority of pipeline codes do allow welders to weld sections of the pipe for welder qualificatio but this is not allowed in ASME IX.

Let's use a 6" pipe welded GTAW in the 6G position as an example.
For a right handed welder one side of the pipe is welded "forehand" (the easiest) and the other side is welded "backhand" or left handed (both more difficult than the forehand side)
How can it be a true competency test when one welder has the easy side and one welder has the much more difficult side ?
Regards,
Kiwi

 

[Kiwi2671]

teokal,
Why did you even require P91 coupons ?
Any P1 material (eg. A106 Gr B) would have been fine. (QW 423.1)
Regards,
Kiwi

 

[SJones]

It's madness to expect a single welder to weld out a 24-inch pipe weld! It's never going to happen during fabrication, so why not qualify it as it is going to happen? As for the 6-inch example, what stops the welder welding from 6 o'clock to 12 o'clock and then swapping sides to do the same?

Steve Jones
Materials & Corrosion Engineer

http://www.linkedin.com/pub/8/83b/b04

 

[teokal]

Thank you for your replies. The reason to qualify on a P91 specimen, is because it is a client's requirement! The welders are already qualified with a CS specimen. And this, additionally to their personal and company qualification on several materials and P Nrs, they have to be qualified for CS and P91 for the specific project... And now I don't have enough material, the client agrees to qualify them with production welds, but now the AI needs 1 welder to weld 1 full circumference of production P91 weld!!! Can you believe it?

Only best result in absolutely necessary time

 

[Kiwi2671]

"Can you believe it" ?
The AI obviously has a better grasp of ASME IX than you or other posters on here.
If ASME IX is the qualification code then you have to comply with that - just because various pipeline codes allow dual welders does not matter at all.
Why on earth are you chasing 24" P91 coupons ? Any small bore coupon will give you the diameter qualification you require.
Regards,
Shane

 

[SJones]

Why on earth are you chasing 24" P91"

Steve Jones
Materials & Corrosion Engineer

http://www.linkedin.com/pub/8/83b/b04

 

[SJones]

Because the qualification is to be performed on production welding and the gentleman is being forced by the AI to get the welder to weld out a complete 24-inch weld on his own. I'm sure that you have a grasp of the time that will take.

Steve Jones
Materials & Corrosion Engineer

http://www.linkedin.com/pub/8/83b/b04

 

[Kiwi2671]

Steve,
Normal industry practice is to qualify welders before they strike an arc. RT of a production weld is used as a last resort.
If the client has moved the "goalposts" at a late stage and not accepted Teokals previous quals on P1 material then the client must bear the time / cost of sourcing the required material,
Regards,
Kiwi

 

[SJones]

Indeed. Or, the client can accept the NDT of a partial circumference that will easily exceed the 150 mm allowed for a plate weld given that the welders are already qualified. Quite what the AI is thrown into the matter for is not clear. That's always a recipe for killing pragmatism.

Steve Jones
Materials & Corrosion Engineer

http://www.linkedin.com/pub/8/83b/b04