ASME IX WPQ question

[AllanEjames]

Hello all,

With regards to welder qualification under section IX. I have a client requesting that all welders to qualified with a 2" SCH 160 and 6" SCH 40 in the 6G position with F3 electrodes all the way out. I can not see what the point of the 6" SCH 40 is when accordance with QW-452.1(b) and QW-452.3, the 2" SCH 160 qualifies a welder for everything the 6" SCH 40 does plus more. The 2" SCH 160 qualifies you to weld from 1" OD to unlimited and to the minimum thickness that the production WPS allows to a maximum thickness of 0.686 (2 X T). While the 6" sch 40 allows a minimum OD of 2.8752" (2-7/8") to unlimited, and to the minimum thickness that the production WPS allows to a maximum thickness of 0.560 (2 X T). So unless I am missing something or that this it is just the way their program is run, is there any reason to conduct a 6" SCH 40 WPQ?

-Thank you, Allan James

 

[DekDee]

Allan,
No reason at all.
Your client obviously has more money than sense.
The usual way if doing two coupons is a thin 2" with a thick 6" so you get maximum diameter, maximum thickness.
Cheers,
DD

 

[aburafdi]

Agree with DD.
Perhaps it's a typo (from your client).......it should be 2" SCH 40 and 6" SCH 160.
Regards,
AR

 

[AllanEjames]

Well why even do a 6" SCH 160, what does that qualify you for that a 2" SCH 160 doesn't? As far as I know the 2" SCH 160 would qualify for everything the 6" does plus get a welder down to 1" OD.
AJ

 

[DekDee]

2" Sch 160 qualifies the welder to 17.48 mm maximum WT.
6" Sch 80 qualifies the welder to 22 mm maximum WT.
6" Sch 160 qualifies the welder to 36.52 mm maximum WT.

 

[AllanEjames]

Oh that's right, I blanked on 6" SCH 160 WT, but isn't it actually unlimited and not 36.52mm do to it being above 1/2" assuming it is 3+ passes?

 

[DekDee]

Correct - my mistake

 

[Duwe6]

Google "supercoupon". One coupon, thicker than XXS, gives Unlimited Thickness qualification. Simple, faster [and thus cheaper] than having to weld two coupons.