What’s the deal with pipe stress?
Well, the truth is that pipe stress is the last thing we think about before completing a file.
Every pipe connects various pieces of process equipment to form a system. Those vessels, tanks, exchangers, pumps, and compressors all come with limits to piping loads on the equipment nozzles, eg., API 610 for pumps, API 650 for tanks, API 617 for compressors…and so on. Since these are typically quite sensitive, that is usually the first thing we do, make sure the piping layout, and restraints result in piping loads within those limits.
Then we make sure there are guides and anchors placed strategically to control the piping expansion, to keep it on its supports, to avoid clashes, and that the loads on the restraints aren’t too high.
Finally, now that the ‘hard’ part is done, we do a final check that the stresses in the piping meet code..B31.3, B31.1, Z662 etc., and most of the time stresses are not the issue. It turns out there is a lot more to pipe stress than just S=M/Z.