"Pipe" is intended to withstand internal pressures from fluids that tend to straighten the "circle" and which will not "kink" or collapse under axial loads. Hollow Structural Shapes Rounds are also "round" hollow steel cylinders, but they are straightened to structural standards and are more suited to structural buckling resistance without failing. Use a seamless HSSR member, NOT a "pipe" even though both will be the same OD, and both may have the same will thickness.
Sure, physically a "drain" (and its cover plate) can be held up. The pipe is "steel" anyways!
But, remember - without straining the calculations too much! - that that drain cover may get run over by forklift trucks or semi-trailers carrying a full load. Or may never see anything more than 1 nekkid person taking a shower and the janitor's mop bucket.
(Of course, some nekkid people might have substantial load themselves .....)
Are you talking about using a piece of angle iron and some ubolts to support a small valve and open ended pipe from the main header pipe that the drain connects to? I can't speak for the typical crazy requirements the nuke boys come up with, but over in the B31.3 world, we support pipe like that all the time. In truth, I find it preferable as you avoid the possibility of breaking the drain line due to thermal movements of the header if the drain line is hard supported/anchored to the ground.
Edward L. Klein
Pipe Stress Engineer
Houston, Texas
"All the world is a Spring"
All opinions expressed here are my own and not my company's.
