Bevel Weld Symbol

[dengmech]

I have a question...

A weld symbol for a T joint between equal thickness plates shows a bevel weld above the line and below the line (double bevel weld). No bevel size or angle is shown. In the tail of the symbol is the word "BACKGOUGE".

How is this interpereted per AWS D1.1, in terms of the size of the bevel welds.

 

[48v]

Backgouging is removing the (polluted) root of a weld from the opposite side of the joint until you expose sound metal from the first weld. The purpose of removing the polluted metal is to prepare for a back weld from the 2nd side of the joint to finish a CJP weld. So if they are showing a single bevel with backgouging, you can be pretty sure that they want a CJP joint. Unless there's a reason to do otherwise, bevel dimensions would be per prequalified procedure TC-U4b.

 

[DVWE]

If you have a double bevel groove without the depth of preparation or groove weld size specified, the groove shall be prepared symmetrically, and the depth of each bevel shall be approximately 1/2 of the thickness of the member being beveled. Weld shall be full penetration.

See AWS A2.4, 7.2.2

 

[dieselofdog]

Agreed. Butt joint is full penetration unless indicated otherwise.