Fluid Free Flowing Through Centrifugal Pump 1

[mmur]

Hello. I have a situation where my system will sometimes need a pump but other times the fluid wont require the pump to move the fluid. This is caused by varying densities of fluid being moved. If I always allow for fluid to be on both the suction and discharge ends of the pump can any cavitation occur? To put it simply when the pump is not needed the fluid will free flow through the pump.
Is this ok? (it is a centrifugal pump)

 

[BigInch]

Almost every major gas or liquid pipeline transmission system that has booster stations every 50 to 100 miles or so along what may be a 1000 mile + route use a bypass arrangement around the stations when operating at less than full capacity and a particular station, or even a group of pumps in a station, are not required for such a low flowrate (but still higher than needed to prevent check valve flutter as such low flows are so uneconomic to pump they are better left to simply shut the whole pipeline down.) In conjunction with an active bypass in such cases, rather than leave both bypass and pump suction open potentially flowing through both routes, a block valve on the pump suction and another on the pumps discharge is closed when it becomes apparent that the pumps can be shut down to send the station into bypass mode. Without block valves and at slightly higher flowrates some flow might be forced through the idle pumps creating unnecessary wear and tear on the pumps and inconvenience in what would otherwise be an opportune time to do some pump maintenance. I'd recommend a very conventional setup with a check bypass and block valves on the suction and discharge of the pump. If you think about it, you would probably like to have them for certain purposes, but they are not totally necessary hydraulically speaking and do make it necessary to have someone, or some remote motor actuator open them again when the flowrate builds up again to where you need to bring the station on line again.

From "BigInch's Extremely simple theory of everything."

 

[1gibson]

Upthrust