"Shear with you" ?????
My general suggestions, based on many years of dealing with trunnion supports is:
1) Trunnion diameter shall be piping not less than 1/2 of the parent pipe diameter
2) Trunnion diameter shall not be the same size as the parent pipe diameter
(Very difficult to fabricate and the larger diameter is usually unnecessary)
Therefore, I would consider: 8 inch NPS, 10 inch NPS and 12 inch NPS all as possible candidates ... Depending, of course on calculation
Do you see where it says that " Trunnion size shall normally be one size down as parent pipe and shall be verified by calculation" ?
You are the pipe support designer ... what were the results of the calculation you performed ?
What is both the material and the pipe schedule of the parent pipe ?
You are not trying to put a trunnion on that shitty Schedule 10/10S piping are you ????!!!!?????/
MJCronin
Sr. Process Engineer