Straight length suction pipe
Straight length suction pipe
(OP)
The suction piping straight length ( after the first elbow) for one of the Between bearing pump ( suction and discharge nozzles - Top),is only 2D. We are not able to increase further . The pumpflow is 1060 m3/hr , head - 320 metres and the temperature of the hydrocarbon fluid is 338 deg C. My query is , whether the straight length requirement is important for horizontal suction piping or applicable for vertical suction also? Whether this minimum straight length requirement of 2D will affect the pump performance badly and lead to any other problems ? Any other way to overcome the problem? The size of the suction nozzle is 16 Inch.





RE: Straight length suction pipe
With those temperatures you may have NPSH problems already and the 2D certainly won't help.
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"Pumping accounts for 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/
RE: Straight length suction pipe
RE: Straight length suction pipe
Overall, I agree with BigInch. You should always try to allow 5 diameters of straight run. And if you can get 10 diameters without too much trouble or expense, take it.
Johnny Pellin
RE: Straight length suction pipe
JJ & Biginch, The NPSH margin avl is only 0.6 metres. As pennpiper was indicating , does this vertical suction have an advantageous role to play?
RE: Straight length suction pipe
RE: Straight length suction pipe
Johnny Pellin
RE: Straight length suction pipe
Makes no sense to me.
RE: Straight length suction pipe
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"Pumping accounts for 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/
RE: Straight length suction pipe
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Johnny Pellin's comments re bends prior to a pump should be carefully read and understood as it is important point and the root cause of many pump inlet problems in the field.
So far as the number of pipe diameters before a pump inlet flange for the pipe length there are no rules, in some cases 2 is OK in others 8 is insufficient - a lot of the problems are introduced well before this point and are carried thru into the pump.
RE: Straight length suction pipe