pipe rack analysis

huangyhg

pipe rack analysis
i am currently analyzing an existing pipe rack in a chemical plant located on the gulf cost. the pipe rack has within it several steam lines of various sizes, along with other chemical process piping. my question is what weight should i use for the steam lines? should it be the weight of the pipe only, or the pipe weight plus some factor for any water that might have collected in the line?
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the pipe loading requirements should come from the piping design engineer.  there are other considerations for the pipe rack also, such as forces induced from expansion and contraction and how the pipe is restrained.  as far as the steam is concerned, the possibility of condensate and a water load should be considered, but again, i would defer to the piping engineer or the process engineer responsible for the selection of the pipe material, etc.
you need to design for the hydrotest when the pipes are full of water, so for gravity loads i would use a pipes full of water.  but steam lines often have huge thermal forces at the anchors.  those loads need to be accounted for and usually come from the piping engineer.  steam lines can be extremely dangerous/deadly if one fails.
if you're doing a prelim design, use the hydrotest for maximum foundation loading. you also want empty loads with maximum wind to test for uplift conditions.
in a final design you will have the neessary stress info to transfer anchor forces through a bracing system to the anchor bay and then it won't matter what is in the pipes.
for existing steam lines, if you have the anchor loads from the original design, the job is much easier. pipe weight with full of water content can be tried first to check the structural strength.