how to make 2G and 5G test combination in one coupon

Date 10-03-2010 09:40

doyenofcastle
You have to weld two test positions.
What the meaning of the table you show is when a person tests and successfully passes welds in the 2G and in the 5G positions they are qualified to weld in All Positions.
I don't have the document you are referring to and can not see what note 1 does to the equation.
Good Luck
Marshall

By doyenofcastle (**)

Date 10-03-2010 10:52

THANKS ,note one

(1) Positions of welding as shown in QW-461.1 and QW-461.2.
F p Flat
H p Horizontal
V p Vertical
O p Overhead

By MBSims

Date 10-03-2010 12:19

It is permissible to use a single test coupon welded in both 2G and 5G positions, or to use separate 2G and 5G test coupons. The guidance is in QW-302.3:

"...For test coupons made in both positions 2G and 5G on
a single pipe test coupon, specimens shall be removed
in accordance with figure QW-463.2(f) or figure
QW-463.2(g)."

If you look at the above figures, there is a 100 degree segment on the left side of the figure for 10" NPS, or 90 degrees for 6 or 8" NPS, that is welded in the 2G position and the remainder is welded in the 5G position. It also shows a horizontal reference line for 5G to make sure the pipe is oriented correctly while welding.

By strat

Date 10-06-2010 18:13

Question, if the welder takes the test in 2G and 5G on a single coupon and the root and hot with gtaw is applied in the 2G and the remander of the test is smaw in the 5G does that not limit him to gtaw in the flat and horizontal only and smaw in the flat, vertical and overhead.

Strat

By MBSims

Date 10-07-2010 02:45

Perhaps, but why would you want to do that?

By strat

Date 10-07-2010 11:39

Agreed, in that situation you would be best of in 6G for all positions in each of the process, maybe im missing something but i dont understand why you would do a combination of 2G and 5G on a single coupon when you can do a 6G and get the same outcome.

Strat

By MBSims

Date 10-07-2010 11:51

I don't know the history of how it got into the code, but it has been there for quite awhile. I recall seeing some major constructors that had this test written into their welder qualification procedures, so perhaps someone uses it. I've never seen it actually given on a job and have not reviewed any welder qualifications that used this test. The 2G and 5G positions are the normal weld orientations encountered on the job, so perhaps some prefer this test over 6G as being more representative of the work to be performed. If that were the case, I would rather see two coupons used, one in 2G and the other in 5G.

By jsdwelder (***)

Date 10-19-2010 23:21

I would agree with MBSims. I think the overhead part of a 5G is more difficult than the overhead part of a 6G.

By jon20013 (*****)

Date 10-20-2010 11:09

Right, the other thing one has to consider if a single coupon were used is what type of testing would be done? If volumetric, I believe you'd need 6 inches from each position. If bend tests, you'd need 2 from 2G side and 4 from 5G side. Sounds like a lot of BS just to prove a point. I'd either require a 6G or 2 separate coupons.