I have received a copy of this paper and have a number of reservations about its use today.
1. It appears to be based on some very old Code design rules. As a minimum, I believe that users should substitute rules of current codes for the allowable stresses presented in Table B. Note that users under B31.1 and B31.3 will use DIFFERENT allowables for some of these cases, even ignoring the different allowables for most materials in the two codes.
2. For typical built-up attachments (as discussed on pages 3 and 4 of the first paper), it appears to be nonconservative to assume that the support force acts on the "center of gravity" (centroid) of the attachment as calculated. I believe that they should instead be calculating the centroid of the CONTACT AREA between the attachment and the support steel. This will, in general, result in the force acting farther from the OD of the pipe than in the recommended calculation method. Fortunately, this is a very rare type of attachment!
3. Reference is made in several places to allowing local stresses to be 2.0 X Code allowables. This sounds like sound design technique for FEA modeling and may well be covered in something like Section VIII or Section III, but I am not aware of anything like this explicitly stated in the current B31 Codes.
4. The tables given for the design of the horizontal trunnions should be avoided like the plague. They are based on allowable materials properties from an unknown Code, in an unknown year. They do not cover many materials in common use today. If you MUST use tables, calculate your own TMF table from the formula given immediately below the TMF table.
5. The note that base support trunnions should not, in general, require reinforcing pads is completely bogus. Most references today recommend re-pads for all piping below Sch. 40.
Although this paper provides a great starting point for the design of a trunnion, it appears to have been written long, long ago. Although it's dated 1988, I am pretty sure it existed in the early 1970's and suspect from the style that it may date from the 1950's or before. Essentially the same equations are presented in the 2nd edition of the Kellogg book, which was published in 1956.
I heartily recommend that users of this technique pay much attention to current design rules. WRC-448 appears to be a far better reference, although it (sadly) does not appear to cover trunnions made of round and hollow material.
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CraigB
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