Is there any calculation dictated by ASME on UG-34 sketch m for example. Of course "t" of flat head you can find, but retaining rings or threads in different sketches, is there any "approved" calculation procedure?
However, I do believe that U-2 (g) will be applicable in this case.
There are also other questions related to sketches like (m).
What should be the shell thickness? Is the minimum thickness under the retaining ring? I think no. It should be the original thickness.
What is the sealing element between shell and flat head, between the outer surface of head and shell, or between the ring and (head & Shell)?