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Up Topic American Welding Society Services / Technical Standards & Publications / Seal Welds
- - By rickc (**) Date 01-19-2009 22:57
We'd like to put a seal weld around a 3" bar to plate connection to keep moisture out - there shouldn't be any loads on the weld. Our Engineering department called out a 1/8" fillet. I don't have my copy of D1.1:2008 in front of me but, D1.1:2006 would like a 5/16" Fillet by Table 5.8 (P.204) for that material thickness. Still well within the maximum single pass thickness so, I suppose I don't really care either way but, I'd obviously prefer to be following the standard.

Any thoughts? Is there a more appropriate code that we should be using for seal welds?

Thx,
-Rick
Parent - - By hogan (****) Date 01-19-2009 23:11
One thing about AWS D1.1 is that the engineer makes the rules. Whatever they say goes, just get it in writing. That connection reminds me of a fab shop I spent 6 weeks at. For the entire six weeks I did not accept one of there connections. They had an issue with the weld cracking around the bar and thought all of my suggestions were incorrect. I later found out that they paid welding engineer a good deal of money to make the same suggestions. The foreman called and explained this to me and then asked me for any suggestions on there current problem. I told them I wanted the rate he had just mentioned for the welding engineer.
Parent - - By rickc (**) Date 01-19-2009 23:49
Dare to dream!
We use alot of ASTM-A514. After welding we have to wait 48 hours before performing our NDT (per 6.11 on P.212). If we find any indications we have to repair 'em and then wait another 48 hours to check again. Like I said, I don't really care what size the fillet is but, I do want it to do its sealing job and I want my welders to be able to weld it right the first time. I think a larger fillet such as D1.1 recommends won't be any more difficult for the welders and it should reduce the amount of cracking we'll see. Better, faster, cheaper.
Parent - - By 803056 (*****) Date 01-20-2009 07:12
The purpose of the minimum weld size requirements (based on material thickness) is to provide sufficient heat input to reduce the cooling rate and prevent hardening in the HAZ.

While the engineer is given wide latitude to make decisions that are contrary to the code requirements, it is in the engineer's interest to understand why the code includes the requirement to begin with. In this case there is a sound metallurgical reason for the requirement. Hopefully the engineer is compensating for the rapid cooling rate by taking other steps to prevent a hard HAZ, brittleness in the weld and HAZ, and potential cracking problems.

Best regards - Al
Parent - - By 3.2 Inspector (***) Date 01-20-2009 14:10
If I may add "avoid thermal stress" to your reply.

3.2
Parent - - By rickc (**) Date 01-20-2009 16:35
The engineer thought he was doing us a favor by making the fillets smaller so, that it would be easier and faster for the welders. I explained that this was not the case, showed him the section in the commentary about fillet weld sizes are, in part, to ensure sufficient heat input to prevent cracking. I explained about the 48 hours for NDT and showed him the section on maximum single pass fillet weld size.
...So, he's gonna make 'em bigger.

Thank you for your help!
Parent - - By mountainman (***) Date 01-20-2009 20:48
atleast there were good intentions on his part to try and minimize time and consumables for your welders. kudos to him for making the effort, you don't see that an awful lot much anymore.

JJ
Parent - - By rickc (**) Date 01-21-2009 01:07
Yeah, it was a surprisingly pleasant exchange!
Parent - By eekpod (****) Date 01-21-2009 11:12
To get back the original post.
The seal weld and the structural weld may be different.  I have seen two different weld sizes called for; one is the "structural" weld that per either the code or the engineer/ drawings is called for, then the other is the seal weld, which is not a structural weld but is nothing more than a small weld to keep water out.
As long as the part is not AESS and visual limitations are not a problem this will work.
If the engineer says an 1/8" is ok, then he can override the code, and do what he says.
Chris
Up Topic American Welding Society Services / Technical Standards & Publications / Seal Welds

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