D17.1 Performance Qualification Thickness Range

Date 01-18-2009 04:02

OK, I believe I have over thought this and now confused myself, which is not hard to do. I know I can count on the superior brian power here to help.
D17.1 par. 4.3.3.1 (1) states "A test weld with a base metal thickness of t shall qualify welds with a thickness range of 0.67 t to 4t, except that when the test weld thickness is equal to or greater than 1", the qualification range is 0.67t to unlimited. Two test welds shall qualify welds with all intermediate thicknesses".
Therefore I can perform two test welds, a 1" and a 0.125" test weld thickness, to qualify .06" to unlimited. Did this come out right?

By ctacker (****)

Date 01-18-2009 08:05 Edited 01-18-2009 08:08

I don't have D17.1 but if you do the math you presented, .125X.67 = .084 so a test plate .125 thick would qualify you to .084 up to .5 and a test plate 1" would qualify .067 to unlimited. so you would have over .5 and under .67 that you wouldn't be qualified for.

By bamaCWI (**)

Date 01-18-2009 12:57

Thanks!

By bamaCWI (**)

Date 01-18-2009 18:49

I want to think that the sentence from paragraph of 4.3.3.1 (1) "Two test welds SHALL qualify welds with ALL intermediate thicknesses" qualifies the difference between 0.67t of the 1" weld and 4t of the thinner weld. This in my opinion would be the intermediate thicknesses refered to. Any input? I don't want to make that call without some confirmation or correction from here. There is never a dumb question Right?

By GRoberts (***)

Date 01-18-2009 19:01

bama,
Based on the language you presented in your post, I agree that any intermediate thicknesses between the two plates are qualified.

By bamaCWI (**)

Date 01-18-2009 19:13

Thanks! The weld foreman will not be happy though.

Scott