7.9.1.2 (6) Interuption in the backing not in corners

Date 09-16-2022 13:59

OK guys ,

Looking for a little bit of interpretation or support. We have a a scenario where a multipiece steel backing has been made continuous and complete prior to installing inside of a multi sided - non square HSS. The previously repaired splice is located in a Corner of this tube. We have an auditor who is insisting that 7.9.1.2 would mean that the previous interruption or splice in the backing that again - has been made to be CJP prior to fitting it into the tube - cannot be in this corner. My interpretation of 7.9.1.2 (6) is that an UNSPLICED unwelded discontinuity cannot be in the corner - but if it is no longer unspliced or unwelded - that there is no longer an interuption to be considered.

7.9.1.2 Full Length Backing . Except as permitted below, steel backing shall be made continuous for the full length of the weld. All joints is steel backing shall be CJP groove welds meeting all the requirements of Clause 7 of this code.

For statically loaded applications, backing for welds to the ends of closed sections, such as hollow structural section (HSS), are permitted to be made from one or two pieces with UNSPLICED discontinuities where all of the following conditions are met:

(I) The closed section nominal wall thickness <lees not exceed 5/8 in [ 16 mm).

(2) The closed section outside perimeter docs net exceed 64 in [ 1625 mm).

(3) The backing is transverse to the longitudinal axis of the closed section.

(4) The interruption in the backing does not exceed 1/4 in [6 mm].

(5) The weld with discontinuous backing is not closer than the HSS diameter or major cross section dimension from
other types of connections.

(6) The interruption in the backing is not located in the corners

By 803056

Date 09-19-2022 16:55

Have you met all the conditions of 7.9.1.2 (1) through (6)?

(5) The interruption would be where the ends of the backing have not been welded together. A gap no more than 1/4-inch is permitted as long as it isn't in the corner.
(6) The interruption can not be located in a corner. If the backing bar is welded with a CJP groove weld, it isn't discontinuous.

My take is that the CJP groove weld can be located in the corner of the hollow structural shape.

Just remember, "He who holds the gold gets to make the rules." You can always go to the Owners Representative, i.e., the Engineer, for clarification. The Engineer has the authority to add to, delete, or modify the Code. He makes the final determination if you are at loggerheads with the Verification Inspector.

Al

By sandeepkumar63 (*)

Date 05-04-2023 08:01

The welding backing types are covered here. https://www.materialwelding.com/backing-bar-in-welding/

By jwright650 (*****)

Date 05-08-2023 11:44

I agree with Al, it seems that you don't have any of the conditions that the auditor is objecting to.