ASME Div. 2 App.4 acceptance criteria

[geng]

I am designing the lifting trunnions of a pressure vessel
and calculate the effect of the loading of the trunnion on the shell as a WRC107 local load calculation.
WRC reports the membrame and membrame+bending stress.

Membrame should be compared to 1.5xSallow.
The allowable membrame+bending is depending on the type
of stress , primary < 1.5xSallow or secundary < 3xSallow.

Can anyone tell me what the allowable membrame+bending stress is for the mechanical loading of a trunnion on the shell.

peter.verbruggen@ggi.be

 

[prex]

The bending stress is a secondary stress, as membrane stresses only can satisfy the equilibrium: I would use 3xS.
I suppose also that the trunnion, as usual, is welded on a doubler plate, and the limiting check should be at the doubler plate perimeter.
Note also that there is no limitation on secondary stresses in ASME VIII div.1, and that your client's specification might give a different limit. Just to make an example, the same stress would be limited to 2.25f under BS5500 (if I remember correctly).
Look at the site below: there's a calculation sheet for WRC297.
prex
motori@xcalcsREMOVE.com

http://www.xcalcs.com

Online tools for structural design