QW-452(b) thickness qualified?

[qcrobert]

I have a contractor stating that his welder is qualified to weld unlimited thickness because his WPQ utilized a pipe thickness of 0.500” as per ASME QW-452-1(b).

I disagree in that I interpret QW-452.1(b) as to state that ALL thickness (t) of weld metal in the Coupon qualifies only to 2t. The following statement in QW-452.1(b) that 1/2” thk. and over with a minimum of three layers qualifies to Maximum To Be Welded, I interpret through notes 1 & 2 only addresses the thickness of each process (or welder(s)) as to be recorded individually and thus noted as 2t weld metal qualified for each process.

Please give your opinions,
QCRobert

 

[weldtek]

qcrobert,
If you're talking about a 1/2" thick test coupon on which a welder was qualified on more than one process, I agree. If however the welder used one process and welded the entire 1/2" thick coupon with at least three layers, he/she would be qualified for /max to be welded'.

 

[qcrobert]

Let me clarify, are you stating that a welder who used one process and welded the entire 1/2" thick coupon with at least three layers, that he/she would be qualified for UNLIMITED thickness?

 

[qcrobert]

Therefore that a welder is qualified to Maximum/Unlimited thickness if said welder successfully welds a .500" (13mm) thick or coupon utilizing a minumum of 3 weld passes with ONLY one process and SAME F number.

Thank you, Weldtek, I just have never come across such a WPQ. The only instance where I could see this being used (in the real world) is the use of E6010 root and E7010 HYP remainder being used in 1104 pipeline welding.

I am more familiar with the use of E6010 root and E7018 rem but that wouldn't qualify for unlimited because of two different F nos. Or the use of GTAW root and SMAW remainder wouldn't qualify for unlimitied because of the use of two processes.

Thanks again for the clarification,
QCRobert

 

[welding8]

Weldtek,
Can welder also qualify to 2.875 OD pipe.
Thanks,

 

[weldtek]

welding8,
Yes within the limits of QW461.9

 

[Duwe6]

Sounds like you are seeing a WPQ done on a "Supercoupon". And, yes a supercoupon gives unlimited thickness for the second process -- welder deposited 1/2-inch of metal. And yes, the Supercoupon is just barely small enough to make the ASME IX requirement for a 'small-bore' coupon and it give a qualified range down to 1"OD - 3/4"NPS pipe.

When they discover them, most Welding Dept's fall in love with Supercoupons. Unlimited wall thickness qual plus a small-bore qualification in one coupon that can be welded out in 4 to 6 hours.

http://www.trieng.com/monster.html

Triangle Eng calls 'em Monster Coupons.

I highly recommend using Supercoupons for all pipe welder and boilermaker quals.