Eddwin
Industrial
- Jul 24, 2009
- 3
Hello,
I am designing piping around 3 parallel centrifugal cooling water pumps.
650m3/hr each, inlet piping 18", outlet 12".
All three pumps have a dedicated inlet pipe, coming from a basin 3 meters upstream. The outlet will be combined into a common header to the plant.
The pump manufacturer states that there shall be no compensators on the inlet or outlet nozzles, because it may disturb the flow and cause or increase cavitation. And that they never see them around the pumps.
The civil and other "experienced" people say they always see compensators around the pumps, and that we need them. But, they can not tell me why.
I would like not to use compensators and follow the manufacturer, but then I will go against my colleagues.
I can think of the following considerations:
1) thermal expansion. I think this should be negligible for cooling water.
2) make up for misalignment. I think with careful installation, it should be possible to get the piping done without compensator.
3) Vibration damping. I don't know if it is required for a centrifugal pump.
4) Settlement between basin and pump foundation. Everything is on piles here, but this could be an issue in time.
5) Noise suppression. I have no clue on this topic. The pumps are not really noisy to begin with.
There seems to be a general tendency to install compensators around compressors/turbines/pumps around my office, but nobody really can explain me why. I'd like to get rid of them as much as possible (some of them are 60 bar/10", so quite large reaction forces will be present.
Anybody there with more considerations/experience?
I am quite new to piping up rotating equipment.
Thank y
I am designing piping around 3 parallel centrifugal cooling water pumps.
650m3/hr each, inlet piping 18", outlet 12".
All three pumps have a dedicated inlet pipe, coming from a basin 3 meters upstream. The outlet will be combined into a common header to the plant.
The pump manufacturer states that there shall be no compensators on the inlet or outlet nozzles, because it may disturb the flow and cause or increase cavitation. And that they never see them around the pumps.
The civil and other "experienced" people say they always see compensators around the pumps, and that we need them. But, they can not tell me why.
I would like not to use compensators and follow the manufacturer, but then I will go against my colleagues.
I can think of the following considerations:
1) thermal expansion. I think this should be negligible for cooling water.
2) make up for misalignment. I think with careful installation, it should be possible to get the piping done without compensator.
3) Vibration damping. I don't know if it is required for a centrifugal pump.
4) Settlement between basin and pump foundation. Everything is on piles here, but this could be an issue in time.
5) Noise suppression. I have no clue on this topic. The pumps are not really noisy to begin with.
There seems to be a general tendency to install compensators around compressors/turbines/pumps around my office, but nobody really can explain me why. I'd like to get rid of them as much as possible (some of them are 60 bar/10", so quite large reaction forces will be present.
Anybody there with more considerations/experience?
I am quite new to piping up rotating equipment.
Thank y