Double V-Grve Weld Using SAW from Both Sides-No Backgouging

Topic American Welding Society Services / Technical Standards & Publications / Double V-Grve Weld Using SAW from Both Sides-No Backgouging

By edsalax Date 10-07-2008 22:45

For spirally welded large diameter steel pipe (16 in. and up to 72 in.), with wall thicknesses of 0.500 in., 0.625 in., and 0.750 in., can a WPS be qualified for this condition (no backgouging when welded from two sides), and still be considered a complete joint penetration (CJP) weld? Double-V would have a root face (with 60 deg. bevel). Section 3.12.1 of D1.1 indicates this as a PJP for a prequalified condition.

By HgTX

Date 10-07-2008 22:52

I think 4.10.4 provides for qualifying a weld that doesn't officially meet the requirements for CJP.

Hg

By Bill M

Date 10-08-2008 16:35

SAW is only pre-qualified in diameters greater than or equal to 24".

I think you could prequalify a subarc CJP joint in this case (over 24" dia only) using B-U3c-S. This would require incorporating some type of "backgouge".

So would cleaning the opposite root surface by grinding before welding the opposite side be possible, and would it comply with "backgouging" definition?

Topic American Welding Society Services / Technical Standards & Publications / Double V-Grve Weld Using SAW from Both Sides-No Backgouging