Shell insert

[edmiester]

I am trying to find out if a proposed shell insert plate would be acceptable per code; I will attempt to describe it since I cannot attach a picture:

-The shell insert plate would be 24" x 24" and it would intersect the cornerweld at a 90 degree angle
-The insert will placed along an existing vertical weld and the horizontal weld would intersect this vertical weld at a 90 degree angle
-There will only be one rounded corner

I think that it cannot be installed this way because:
-API 653 section 9.2.2.1 describes the repalcement plate as having "rounded corners", which to me means it needs to have at least 2
-secondly, Figure 9.1 in API 653 does not show this to be an "acceptable" layout and one of the patches shown in this figure crosses the vertical weld by at least V or needs to stay away from a vertical weld by at least V

Your opinions would be greatly appreciated. Thank you.

 

[Duwe6]

Sounds acceptable to me. Couple of 'compliance' points;
Weld the vert first, to allow the hoop shrinkage from the weld to occurr unimpeded, then weld the corner.
Ensure that the rounded corner on the insert is generous - 2" min. radius, but more is better. Watch for notches and other 'oopses' where the corner transitions into the flat side - they create stress concentrations.
Finally, weld all of one side of the corner weld and perform the required 'diesel oil' leak test prior to starting on the other side.