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Up Topic American Welding Society Services / Certifications / AWS D1.1-2004: Ref 3.6.1
- - By Pedro Coloma Date 12-05-2004 05:01
Dear sirs, I`m CWI inspector working in South America...I`m from Peru.I have some problemas trying to understand D1.1-2004:ref 3.6.1. :
1. According to this reference, is it possible to use a combination of two prequalified WPSs?Have you ever seen a case?
2. Would somebody send me an example of a permitted combination?

Thanks
Pedro

Parent - - By DGXL (***) Date 12-05-2004 05:34
Hola Pedro:
An example of 3.6.1 would be a weld performed with the SMAW process on the root pass and the FCAW process is used for fill and final passes.

The key phrase of the paragraph is: "...limitation of essential variables applicable to each process..."

Bueno suerte.
Parent - - By Pedro Coloma Date 12-05-2004 13:40
Ok, Let me try to propose an example:

A contractor uses two Prequalified WPS:

1. Process: FCAW, Filler metal classification: E71T-11,Type of joint:B-U2-GF, Position:V,Base Metal Classification: ASTM A572 Grade 50, BM Thickness: 1/2" ( permitted by Table 3.1),Minimun Preheat Temp.:20 ºF

2. Process: SMAW, Filler metal classification: E7018,Type of joint:B-U2, Position:V,Base Metal Classification: ASTM A572 Grade 50, BM Thickness: 1",Minimun Preheat Temp.:80 ºF

Now, this contractor is asking me for authorization in order to use:

3. Process: SMAW+FCAW, Filler metal classification: E7018+E71T-11,Type of joint:B-U2-GF ( or B-U2, it`s exactly the same), Position:V,Base Metal Classification: ASTM A572 Grade 50, BM Thickness: 1 1/2" ,Minimun Preheat Temp.:100 ºF


This is my opinion:
-B-U2 and B-U2-GF require the same joint design tolerances: NO PROBLEM
-There is a restriction in "Base Metal Thicness" with E71T-11 ( How does D1.1 deals with the " Weld metal thickness deposit" concept established in ASME IX? D1.1 establishes the " Base metal thickness" concept apparently); So I`d accept only the following combination: 1" E7018 + 1/2" E71T-11. But , because of productivity, maybe, it does not make sense to use it.
-Minimun Preheat Temp.:100 ºF : NO PROBLEM


What do you think about it?

Pedro
Parent - By pipewelder_1999 (****) Date 12-05-2004 15:17
I have experimented with Welding over deposted 71T11 with GTAW, Gas Shielded FCAW and Even GTAW. The results were interesting in the fact that all welds deposited over the 71T11 contained porosity in large amounts the the entire length of the weld. No idea how it works the other way.

Of course this was not a scientific experiment and I never tried SMAW. Or welding over the other processes with FCAW-SS

Deposited weldmetal thickness is only referred to in reference to the thickness of a single pass.

Each Dia of E 71T11 may have a different allowable deposited thickness
based on manuacturers specifications.

GA
Up Topic American Welding Society Services / Certifications / AWS D1.1-2004: Ref 3.6.1

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