prequalified joint detail question

Date 07-05-2012 19:17

All the D1.1 prequalified joint details for single bevel groove welds (B-U4a for example) when shown in the horizontal position, have the beveled side on top. The top plate is always shown beveled, the bottom plate is always flat, with no bevel.

I realize the joint is allowed for all position welding. But my question is when in the horizontal position, if the joint is prepared upside down as shown, with the bevel angled down instead of up, and the top plate is flat with no bevel, ..is the joint still prequalified?

thnx

By welderbrent (*****)

Date 07-05-2012 19:54

My question is: why would you want to?? The purpose is to give a good shelf for the weld especially at the root and then add 'width' (height) as you come out with the fill passes.

Did someone mess up and do things upside down? Or is there another reason behind this inquiry?

Have a Great Day, Brent

By Bill M

Date 07-05-2012 20:04

Yeah man, I certainly agree with you!!

I am just reviewing the drawings and found the joint drawn this way...

Attachment: weldsketch.doc (24k)

By welderbrent (*****)

Date 07-05-2012 22:09

That drawing explains things a little more. Now, I assume that is the way the finished product will look...thicker part on top and thinner on the bottom??

If so then it is much easier from the materials preparation to fit up to do it as drawn. Welding may be slightly more difficult but far from a problem, especially for the right welder.

Much easier to prep the bottom piece on the whole thickness rather than trying to get an even bevel only part way through the heavy member.

And yes, the joint is still pre-qualified.

Have a Great Day, Brent

By 803056

Date 07-06-2012 14:08 Edited 07-06-2012 14:46

I'm not sure what your level of involvement in this operation, but there is an issue that should be given careful consideration.

Lamelar tearing in the thicker member is a potential problem with the joint configuration as detailed. Since this is posted under the heading of D1, I assume it safe to say you are working with AWS D1.1 if you are welding carbon or high strength low alloy steel. That being the case, due consideration to the cautionary comments of clause 2.7.3 and C2.7.3 (D1.1-2010) should be reviewed.

Best regards - Al