Coupon thickness vs. weld metal deposit

Date 08-18-2005 17:31

I would like the issue clarified about the weld metal thickness deposited and what it qualifies for in the AWS B2.1. Under 3.4.3 it references that it should be recorded but does not elude to for what it qualifies for. If I understand it correctly there is a coupon thickness qualification , size of pipe and metal deposited. per process. ASME explains it but the copy of B2.1 that I have does not make it real clear unless I missed something on this one. Any clarification would be appreciated. Use example of coupon thickness vs.weld metal deposited. The 5/8 wall thick 2" pipe where you put in the root with GTAW and stick out.
t is metal deposited. and T is coupon thickness. What is qualified

By jon20013 (*****)

Date 08-18-2005 18:13

Check www.sperkoengineering.com and look at this link:

http://www.sperkoengineering.com/html/articles/Sage%20Advice%20on%20SWPSs.pdf

By Jim Hughes (***)

Date 08-18-2005 23:56

Since XX strong 2" is only .436 wall, you must be using a supper coupon. If it were ASME your GTAW would be 0.250 and your SMAW would be unlimited. But AWS says it has to be 3/4" to get unlimited on pipe. So your GTAW would be .250 and your SMAW would be .500. On both, your qualified down to 1" and unlimited on diamiter.
Jim

By MBSims

Date 08-19-2005 04:15

I'm not that familiar with B2.1, but shouldn't he get "2t" for the SMAW. Typically the 5/8" wall x 2-3/4 OD pipe used for the super coupon would have 1/8" deposited weld metal for GTAW and 1/2" deposited weld metal for SMAW. As you say, it would qualify for 1/4" max deposited weld metal for GTAW. But it should qualify for 1" max deposited weld metal for SMAW under B2.1.

By jon20013 (*****)

Date 08-19-2005 09:29

If properly documented (three layers minimum) 1/2" of process deposit should allow the welder unlimited thickness.

By Jim Hughes (***)

Date 08-19-2005 16:35

MBSIMS,

you are right. My mistake. It would be 1" max under AWS.
Thanks
Jim

By firstpass (**)

Date 08-19-2005 17:08

Thank you for the interest in answering the question. Now let us add the prequalified joints in the AWS code. where it is just fill in the blanks.
This is an issue on jobsites where there are short jobs. Most of the time the contractor does not have a procedure. As an inspector to a one or two day job I generally just document the fact that there is no procedure and pass it on to engineer. Normally the engineer of record is not trained in the welding area. How can this issue be resolved where compromise of rules that are required are not circumvented.

By jon20013 (*****)

Date 08-19-2005 17:14

You'll probably get loads of responses to this "new scenario" but my opinion is that on those short, one or two day jobs, it cannot be resolved, it can only be documented as you apparently are already doing.

Depending on the job duration, the amount of welding and the number of processes being used, perhaps you could generate a little overtime by offering to assist, or guide the engineer of record in completing required pre-qualified forms. This however is just a thought.

By Barbosa Norbert (*)

Date 08-20-2005 01:10

HI EVERYBODY. I'M NEW AT THIS ARGUMENT ABOUT WELDING ON THE WHOLE. I'D LIKE TO KNOW HOW TO MEASURE THE THICKNESS OF A GIVEN METAL BASE REGARDING TO A PROCEDURE QUALIFICATION AND A PERFORMANCE QUALIFICATION. I DON'T HAVE AN (AWS D1.1) AT HAND NOW. SO IF SOMEONE HAS AN IDEA OF HOW TO GET IT BY E-MAIL. I'D BE GREATFUL. FOR EXAMPLE IF I WELD A PROCEDURE WITH AN 1/2 PLATE, WHAT WOULD BE THE LIMITATION OF MY QUALIFICATION ON A PERFORMANCE QUALIFICATION AND AN PROCEDURE QUALIFICATION?

THANKS A LOT.