As someone who does pipe stress work occasionally, but is extremely interested in the subject, I have had trouble finding an answer to the following question. Is there a set of guidelines that I could use, on a very large chemical plant piping job for instance, to cull out pipe runs that do not need analysis? I am familar with paragraph 319.4.1, but that seems very restrictive (...no intermediate restraints...). Is there a generally accepted temperature differential limit, or other criteria? How do the pipe stress masters determine which lines to analyze and which should be ok?!?