Is welder required to recertify?

Date 10-10-2002 13:39

I have an Inspector holding our erector up until our erector recertifies his men(they were tested 3G and 4G on 1" steel plate with a B-U4a joint).

We have a prequalified B-U4b joint with 3/16" root(0-1/8", plus 1/16 fit up tolerance) and the erector is using ceramic backing to put the root pass in to prevent melting through, then is removing the backing and back gouging to sound metal and filling back up the second side full again.

The Inspector says the erector must recertify because of the use of the ceramic backing material rather than steel backing. I say He's wrong because it is a joint that is welded per the prequalified joint design, the backing is only used to prevent melting through(per Section 5.9, & 5.10 D1.1).

By R. Johnson (**)

Date 10-11-2002 12:22

Have the inspector read section 4.23. The qualification on joints with backing qualifies for welding production joints that are backgouged and welded from the second side.
Qualification with a backing bar would not qualify the welder if they were trying to get a complete joint penetration from one side without backing but since the erector is backgouging this is not a problem.

By jwright650 (*****)

Date 10-11-2002 12:27

Thanks for your reply!
I have read the section you stated and also the parent section 4.20 where it tells you to look at 4.23. Sometimes when you are challenged on issues like this by another CWI, who has been in this longer than yourself, you tend to question whether or not you are interpreting it correctly.

By JINX

Date 10-15-2002 18:48

Very interesting question, the prequalifieds can be confusing. Just to add a little. The Standard Symbols for Welding , Brazing, and Nondestructive Examination can add an interesting twist to interpertation. Page 26 of the ANSI/AWS A2.4-98 shows a typical backing symbol and states if backing is to be removed the backing type is to be indicated in the tale of the symbol, (copper, flux, glass tape, ceramic, iron powder, or similar material to prevent melt through) and the letter "R" in the backing symbol to indicate removal after welding from one side. If the welding symbol on the drawing does not meet this requirement, I agree the inspector has a justifiable comment.

By jwright650 (*****)

Date 10-16-2002 11:24

Thanks for your input, that is a very interesting section(4.8 AWS A2.4-98). I learned something today. I never thought about the fact that it should be noted on our erection plans as per this section. I will issue a revision to the drawings to include these notes about the backing.

Monday, Oct. 14, 2002, I drove 735 miles to the jobsite and met with the inspector, the general contractor, the erector, and the engineers that had hired the inspector. All these issues were resolved, after we talked about what the erector and I were trying to accomplish with the ceramic backing. Some of joints are hard to get to and makes it a tough job welding when you are in the air at these heights. And everyone agreed that if the erector wasn't very careful and burned through, he would have a very big mess to fix, therfore the ceramic backing made sense to all involved.