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WQT 3G Position

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rjenyoy12

Structural
Nov 17, 2012
25
This concerns the welder's qualification test (WQT) particularly on the position 3G. Since I am not in the QA/QC side, I am wondering why the testing done was not totally vertical (90 degrees) but instead inclined. Thus, the welding is actually done about 81 degrees. When I asked the QA/QC people, they told me that it is allowed since it is within the 10% tolerance. Even the inspectors from ABS (since the structures were for offshore projects) who were there did not have any objection on the WQT method. My concern was that, is it not that the WQT should be done vertical up at 90 degrees as 3G. I believe, testing the welders should be stringent enough not giving the excuse that there is a 10% tolerance.
 
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rjenyoy12,
As inspectors it is our job to ensure the welders comply with the code, not query why a code committee has made a decision.
As an ex-welder I can assure you a weld in the 3G at 80 degrees is more difficult than a weld at 90 degrees.
If you can get access to a copy of AWS D1.1 have a look at Fig 4.1 - the diagram shows allowable tolerances in various positions,
Regards,
Kiwi
 
Figure 4.1 is used to determine what test position(s) is required based on production requirements. The figure does not depict the variation in the orientation of the test coupon when taking the performance test or when qualifying the WPS.

I agree with the first post, when testing in the flat position, the test coupon is oriented such that the face of the weld, be it a fillet weld or a groove weld is parallel to earth. If the test position is vertical, the face of the weld is vertical to earth. If the weld is overhead, the face of the weld is again parallel to earth, the difference being the weld in made from the underside of the coupon.

The only exception I am aware of is per figure 4.4 where the tubulars are permitted a variance of +/- 15 degrees for the 1G, 2G, and 5G positions. The 6G is only permitted a variance of +/- 5 degrees. I see no such provisions for plate tests and I definitely see no provisions to use the ranges depicted in figures 4.1 or 4.2 for the purpose of welder performance testing or for qualifying the WPS.

As an example: If the production weld is to be performed such that the angle of inclination for the groove is 10 degrees and the angle of rotation is 200 degrees (with 0 degrees being such that the face of the weld is parallel with earth and is on the underside of a plate) the test position required to qualify the welder is flat. However, if the orientation of the production weld was such that the angle of inclination is 25 degrees and the angle of rotation is still 200 degrees, the required test position is now vertical.

The test position required to qualify the welder is vertical (3G) based on the parameters of 25 degrees inclination and 200 degrees of rotation. The inclination of the test coupon is not 25 degrees and the angle of rotation is not 200 degrees. Rather, the angle of inclination is 0 degrees and the angle of rotation is 180 degrees.

When setting up test coupons, I use a 6 inch spirit level to set the orientation. The bubble must be between the two parallel lines. Once the test coupon is in the test position, it cannot be moved until the test is completed. If the coupon is too high, the welder can stand on a block of wood. It the test coupon is too low, the welder can crouch. After all, the welder determines the “comfortable” height when he sets up the test coupons.


Best regards - Al
 
Al,
Can you please explain your comments further:

"Figure 4.1 is used to determine what test position(s) is required based on production requirements. The figure does not depict the variation in the orientation of the test coupon when taking the performance test or when qualifying the WPS."

Figure 4.1 references 4.3.4
Figure 4.1—Positions of Groove Welds (see 4.3.4)

Section 4.3 is titled:
4.3 Common Requirements for WPS and Welding Personnel Performance Qualification

Sub-section 4.3.4 states:
4.3.4 Positions of Welds. All welds shall be classified
as flat (F), horizontal (H), vertical (V), and overhead
(OH), in conformance with the definitions shown in Figures
4.1 and 4.2.

Reading that I would think the tolerances of Fig 1 are applicable to WPS and WQ testing.
Is there a clause somewhere else I have missed that disputes this ?
Regards,
Kiwi
 
I run across welders constantly who want their 10 degrees. I do not allow it simply because my opinion is that if there were tolerances for testing it would be listed in Fig. 4.3 - Positions of Test Plates.
I agree with GTAW that 4.2 is informing you of what welder qualification position is needed for a certain axis and rotation point.
 
Guys,
Found this article by Walt Sperko in The Fabricator magazine.
There is a much more in depth power point presentation on Now Walt is the Vice Chair of the ASME IX committee so this article is obviously based on ASME IX but the Positions diagram for AWS D1.1 (Figure 4.1) and ASME IX (QW 461.1) are exactly the same diagram so it does raise a question - why would one code allow tolerances for setting up welder qualification plates and another not allow when they are basically using exactly the same positional information ?

QW-120 TEST POSITIONS FOR GROOVE
WELDS
Groove welds may be made in test coupons oriented in
any of the positions in figure QW-461.3 or figure
QW-461.4 and as described in the following paragraphs,
except that an angular deviation of ±15 deg from the specified
horizontal and vertical planes, and an angular deviation
of ±5 deg from the specified inclined plane are permitted
during welding.

Regards,
Kiwi
 
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