1/2" diameter WPQ qualified with Volumetric NDE

[Pickaspot]

ASME Section IX
QW-452.1
Thickness of weld metal qualified

Production application 1/2" NPS (.840" OD) schedule 80 (.147" wall)open butt groove weld (GTAW out)P4 to P8.

WPQ qualified with volumetric NDE, welder produced 3qty. 1/2" schedule 80 coupons meeting the 6" (QW-302.2)section IX requirement in the 6G position utilizing GTAW out.

My question specifically is in regards to QW-452.1(b)Note(2)which states:

Two or more pipe test coupons with different weld metal thickness may be used to determine the weld metal thickness qualified and that thickness may be applied to production welds to the smallest diameter for which the welder is qualified in accordance with table QW-452.3.

For some reason....my interpretation of note(2)is that this would actually give the welder a thickness qualification range of .882"?

I have asked some of my colleagues, one agrees and two disagree. For the two that disagree their interpretation is that if the welder welds the 1/2"nps (.840"od)(.147" wall) coupon and a 2"nps (2.375"od)sch80 coupon (.218" wall)the welders thickness qualified would be (.436" max)with reference to note(2)I see it as being .73" qualified thickness?

Back in my rod burning day's I took several small diameter test's (boilers)as stated above producing 3qty 1/2" coupons for RT. Why would most implement the two additional 1/2" coupons when all they would need is one 2"nps coupon as a result achieving the 6" requirement and adding to the thickness qualified while reducing test time, cost and difficulty for the welder?

Does anyone else interpret note (2) the same or am I just nuts? LOL!

 

[metengr]

Note 2 applies to ... Two or more pipe test coupons with different weld metal thickness, which would correspond to different diameters. So, in your case, you had a welder produce two more of the exact same coupons with no difference in weld metal thickness to meet QW-302.2. Therefore, you cannot increase the thickness qualified using Note 2.

 

[Pickaspot]

meteng.

I am still in question on this scenario...

Would it be acceptable to perform the WPQ for the referenced production application utilizing sch. 80, 2"nps and the 1/2"nps coupons instead of the way I qualified him with the three 1/2" coupons? The result being the welder is qualified for 1/2"nps to unlimited diameter, and a max thickness qualification of .436"?

Thank you

 

[metengr]

Yes, that would have been in line with Note 2.

 

[DVWE]

The result being the welder is qualified for 1/2"nps to unlimited diameter, and a max thickness qualification of .436"?

Pickaspot,

Yes that is correct. You do not add your thicknesses together and then times by 2 as you mentioned in your earlier posts.

 

[david339933]

FYI...

Interpretation: IX-92-59
Subject: QW-306, Combination of Welding Processes; QW-452.1 and QW-452.3,
Performance Qualification Thickness Limits and Test Specimens
Date Issued: February 22, 1993
File No: 92-206
Background: The combination of welding processes and pipe diameters listed below were used for performance qualification:
(1) 2 in. Sch. 80 (.218) pipe with open butt using GTAW process.
(2) 2 in. Sch. 160 (.343) pipe with consumable insert and fill pass using the GTAW process and the remainder welded with SMAW process.
(3) 6 in. XXS (.864) using SMAW process with backing.
Question: Using the combinations listed in the Background, in accordance with QW-306, Note 2 of QW-452.1 to determine maximum thickness qualified, and QW-452.3 for minimum diameter qualification, is the welder qualified to weld on unlimited thickness and diameters above 1 in., using either an open butt joint or a consumable insert with the root layer deposited with the GTAW process and the remainder deposited with the SMAW process?
Reply: Yes.

 

[CWEng]

Would it be acceptable to perform the WPQ for the referenced production application utilizing sch. 80, 2"nps and the 1/2"nps coupons instead of the way I qualified him with the three 1/2" coupons? The result being the welder is qualified for 1/2"nps to unlimited diameter, and a max thickness qualification of .436"?

You have to complete two tests to do this, so you can combine the two tests to increase the thickness, but have to weld 6" of 2" pipe (one pipe) and 6" of 1/2" pipe (3 pipes)