Weld Symbol Clarification

Date 12-10-2002 20:58

Yes, this weld would be a CJP weld. The first 1/2" means the depth of preparation and the (1/2") indicates the effective throat thickness of your weld.

Regards,
Sean

By jwright650 (*****)

Date 12-10-2002 20:58

Not if there is no back gouging done or backing bar in place, so D1.1 section 3.12.1, says it is a PJP.
Hope this helps clarify your question,
John Wright

By Louis

Date 12-10-2002 21:02

It depends AWS D1.1 code does not recognize it as such unless it is welded with backing strip or backing weld or back gouged and a bead ran on the back side. If one of these are done and complete penetration is achieved then D1.1 would agree that it would be a CJP weld.
If you have only a single-bevel weld symbol with these dimentions and that is all. This would mean the weld is made from one side only without backing and D1.1 would call it a PJP.
Louis

By jwright650 (*****)

Date 12-10-2002 21:09

Agreed,
What he has described is a joint that was filled completely, and not actually complete penetration.
John Wright

By Sean

Date 12-12-2002 12:35

Sorry about my advice, I confused my codes. I didn't have the AWS code with me when I replied and forgot that this was one of the differences between the Canadian Standards and AWS D1.1.

In Canada, one can have a CJP weld, welded from one side provided the procedure and welder are both qualified. I should have confirmed that this was also the case with AWS D1.1..

By kpauley (*)

Date 12-12-2002 13:33

Thank you all. I was 99% sure that this was not "Technically" a pre-qualified CJP, but I just needed a little reassurrance.

By pipewelder_1999 (****)

Date 12-12-2002 15:20

I may be way off base here but I say that that is a complete penetration weld symol. The effective throat and depth of preparation both indicate complete joint penetration. This has nothing to do with D1.1 or any code. AWS A 2.4 or 3.0? (my memory fails me) indicates this signifies CJP.

What if the groove symbol were ommited. What would that signify? I say CJP. I will try to get the welding symbols book out and see and adjust my comments accordingly with efernces to standards as opposed to my own opinions based on things learned long ago. Boy if I'm wrong, I sure have been a pain to many fabricators over the years.

Just because its not a "Prequalified" joint dosen't mean its not per AWS D1.1. What about CJP welds in structural tubing? Some are done without backing.

Gerald Austin
WWW.weldinginspectionsvcs.com

By jwright650 (*****)

Date 12-12-2002 15:48

Gerald you are correct in that your last example is for tubular connections without backing, see Para. 4.12(2) and Para. 4.12.2, these reference Fig. 4.24 showing the joint you are talking about.
I'm not sure a non tubular connection falls into the same category, see Para. 3.12.1 for definition of PJP. Also for a tubular connection to be prequalified welding must be from both sides or one side with backing.
Confusing?
John Wright

By jwright650 (*****)

Date 12-12-2002 16:38

Gerald,
I got out my AWS A2.4-98 Symbols book, I couldn't find anything to support either of our positions on this. It merely states that He has a 1/2" bevel and 1/2" weld on the arrow side only. It really did not call it either PJP or CJP, only stated what it means as for prep and weld size.
Get your copy out when you get a chance and help me.
John Wright

By pipewelder_1999 (****)

Date 12-12-2002 17:21

If a 1/2" weld size is required in a groove weld for a 1/2" thick plate, can that be achived without full penetration?

G Austin

By pipewelder_1999 (****)

Date 12-12-2002 17:19

Very confusing, but still interesting. When I get back home I will train myself up in this matter.

G Austin

By jwright650 (*****)

Date 12-12-2002 17:25

I agree, but anything I can learn new or better understand, is fun to me.
I enjoy reading all these posts on here.
Have a great day,
John Wright

By bmaas1

Date 12-12-2002 19:01

It would clear everything up if they put that tiny, little melt thru symbol on the other side wouldn't it. HA HA

Brian Maas

By jwright650 (*****)

Date 12-12-2002 21:14

It's funny we are talking about this because I have some skewed tab plates that are 3/8" thick and get 3/8" weld, the tab is skewed at 45 degrees creating a 3/8" deep bevel. Weld symbol shows 3/8" groove weld in the bevel.
John Wright

By CHGuilford (****)

Date 12-13-2002 15:23

I often find that the detailers really don't know what they want for a weld symbol. So they use the symbol they find on the contract drawings, or else something from a previous job that was "almost but not quite.". Of course, the person who put the symbols on the contract drawing doesn't know which ones to use either. That means send out RFIs to find out the intention, or, if we can't contact the responsible party, make all grooves full-pen. Other than for cost issues, that is the easiest way to go, even though what was intended might have been only a seal weld.
It would really help if detailers were required to make welding symbols that comply with AWS A2.4 and the checkers looked for them.

CHGuilford

By jwright650 (*****)

Date 12-13-2002 15:56

We made our 3/8" plate full pen also just to be on the safe side. I filled the groove up and backgouge the backside and filled it back up. Alot of times we end up filling the groove and putting a fillet weld up the back if full pen was not required.

I agree 100% about the detailers and checkers needing to know alittle about welding and the correct symbols to use. I was a detailer and a checker in my former life outside of the shop. I would ring up drawings when I was checking, for incorrect weld symbols, and catch flack for it. But it all stems back to the fact that they simply don't know.

I had met with a Community College here in town and they developed a course that was "Welding for Non-welders" and it taught basic principles of welding and the symbols. It was directed toward managers and engineers that wanted to learn more about what they are asking the shop to do.

John Wright