Maximum Pipe Deflection
Maximum Pipe Deflection
(OP)
I'm working on a project where we're exposing a pipeline while it is in service to repair some damaged coating. I'm wondering how to figure out the maximum allowable stress due to the bending of the pipe, so that I can decide how much pipe to excavate at one time. Any help would be greatly appreciated.
Thanks
Thanks





RE: Maximum Pipe Deflection
Do a stress analysis of the pressured line while "virtually" removing restraining soil and "virtually" increasing the unsupported length until you are nearing maximum allowable stress, then shorten that unsupported length by a safety factor, and/or support the pipe with sand bags at intermediate locations. Be sure to replace any underlying soil removed with sand cement bags that will guarantee adequate support in the future.
If its a gas pipeline see allowable stress clauses of ASME B31.8, liquid line see B31.4
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"Pumping systems account for nearly 20% of the world's energy used by electric motors and 25% to 50% of the total electrical energy usage in certain industrial facilities." - DOE statistic (Note: Make that 99.99% for pipeline companies) http://virtualpipeline.spaces.live.com/