four corner cutout/weld?

[dcceecy]

We designed some shoes/anchors for gasoline pipe. a bunch of steel plates are welded together and then welded to the pipe. One of reviewer's comments is "new compliance calls for a four corner cutout/weld. As shown it would appear to be four point weld". I do not understand what that is.

Can anybody help me on this?

 

[dhengr]

Dcceecy:
We can’t see it from here and a ‘bunch of steel plates are welded together’ is a little short on a meaningful description. They probably don’t want you welding into or around sharp corners, particularly on the pipe. Your sketch is so incomplete that it is tough to tell. You’re just not likely to get any good answers if you can’t define your problem any better than you have. A copy/attachment of the detail his note pointed to might do the trick.

 

[dcceecy]

Please see the attached pdf for the details. Thanks.

 

[paddingtongreen]

I'm not familiar with the expression, but in the anchor detail, I would clip "ratholes" in the four corners from the 11 1/4" plate so that you don't have weld on weld on weld.



Michael.
"Science adjusts its views based on what's observed. Faith is the denial of observation so that belief can be preserved." ~ Tim Minchin

 

[dhengr]

Dcceecy:
Normally you do not want to weld into any inside corner from two or three directions. You stand the possibility of getting some really nasty biaxial or triaxial stresses and residual stresses from the welding, and the potential of crack starters in that corner. As Paddington suggested, you can clip inside corners on stiff. pls. so they can’t weld into the corners. They probably don’t care much about this down further on your shoe, but they sure do up on the pipe. API or some such stds. will govern what you can do on that pipe. But, this same thinking does apply on your shoe details. On details 3/G & 1/G, you want an 11" long fillet weld to the pipe, stopping .5" from each end of the .5" pl. You do not want that fillet to the pipe around the end of the .5" pl. That weld to the pipe would be even better if it could be located +/- an inch or so and welded to the pipe in a down hand position. Then your .5" pl. would be only 8" long, and it would fall where it would on the base pl. and that would be the field weld, down hand. On details 4/A & 2/A, the same thinking applies, I would not weld over the top edge of the saddle pl. to the pipe. I would stop the saddle welds to the pipe .5" short. I would make the saddle pls. and the longitudinal pl. a sub-assembly and apply them to the pipe with down hand welding if I could. Then make my base pl. 6-8" longer and weld to that down hand also. Also, move the bolts in 1" to improve wrench clearance. Alternatively, the only field welds in your det. 2/A should be the longit. welds and the saddle welds to the pipe, the entire shoe should be a sub-assembly.

When you try to weld around the standing edge/corner of a stiff. pl., that is, from the longit. weld around the end of the pl. to the other longit. weld, your det. 1/G at the pipe, you will almost always have the base metal at the pl. corner slough into to fillet puddle, and this leaves a really nasty notch. This is often double trouble in overhead field welding. There is a long winded fix for this and an explanation of why it happens, but just don’t do it.