Pump Station Suction Pipe
Pump Station Suction Pipe
(OP)
Hello everyone,
I am reviewing a design of water pump station which is fed by an open tank. from the hydraulic point of view, will there be any problem if the impeller level was higher than the tank intake level, although the NPSHr is satisfied and the minimum water level in tank is still higher than the impeller level by 1.5m?, in other words, the suction pipe is going upwards.
Thanks in advance
I am reviewing a design of water pump station which is fed by an open tank. from the hydraulic point of view, will there be any problem if the impeller level was higher than the tank intake level, although the NPSHr is satisfied and the minimum water level in tank is still higher than the impeller level by 1.5m?, in other words, the suction pipe is going upwards.
Thanks in advance





RE: Pump Station Suction Pipe
It is a capital mistake to theorise before one has data. Insensibly one begins to twist facts to suit theories, instead of theories to suit facts. (Sherlock Holmes - A Scandal in Bohemia.)
RE: Pump Station Suction Pipe
Theoretically, there is no concern. But my concern has been because I have never seen such case before.
RE: Pump Station Suction Pipe
With only 1.5 meters of cover, it is possible that, at minimum pumping level, you could experience suction vortices.
These are somewhat common with Cooling Tower Water pumps
http://www.baltimoreaircoil.com/english/resource-l...
https://www.youtube.com/watch?v=2MTIoagkpyc
You may have to consider a baffle in the final design
Was there a mistake in the concrete drawings or perhaps a mistake in the amount of grouting for the pump baseplates ?
MJCronin
Sr. Process Engineer
RE: Pump Station Suction Pipe
I'm a little confused by what you mean by "higher than the tank intake level" Do you mean nozzle?
A simple sketch always helps in these circumstances.
Remember - More details = better answers
Also: If you get a response it's polite to respond to it.
RE: Pump Station Suction Pipe
Following sketch shows what I mean.
Nozzle level = 104.51m
Impeller level = 106.00m
Minimum operating water level in tank = 107.52m
What I mean by 1.5m, is the deference between impeller level and minimum operating water level (107.52-106=1.52m)
Nozzle submergence is checked in accordance with ANSI/HI 9.8-1998 and found enough (no vortex problems), =107.52-104.51=3.00m
RE: Pump Station Suction Pipe
As wise men on these for a have said in the past: MORE INFORMATION = BETTER ANSWERS
MJCronin
Sr. Process Engineer
RE: Pump Station Suction Pipe
http://www.pdhonline.org/courses/m134/m134content....
RE: Pump Station Suction Pipe
No problem hydraulically, just remember a sump type system will collect solid matter faster and you need to have access to it.
Remember - More details = better answers
Also: If you get a response it's polite to respond to it.