Basic pump operation
Basic pump operation
(OP)
Excuse my ignorance but this is driving me crazy - If the discharge pressure of a pump is greater than the suction pressure then why doesnt the flow go backwards through he pump?
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RE: Basic pump operation
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RE: Basic pump operation
The pump captures a bit of fluid, adds energy and pushes or slings it out the discharge end. There is some recirculation from the high pressure to the low pressure areas that goes through the mechanical clearances, but usually not all that much.
If you connect the discharge to the suction with a clear plastic pipe segment going around the exterior of the pump, you'll see the high to low pressure flow.
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RE: Basic pump operation
These wear-rings are fixed into the pump casing, and the impeller (the pumping mechanism), rotates inside them. There is a very small clearance between the impeller and the wear-ring and this acts like a labyrinth seal.
As long as the discharge is open, there will be very little recirculation within the pump.
If you start to close the discharge, then more and more pumped product will circulate inside the casing. You will also notice that, as there is reduced "flow" through the pump, it will heat up. You will also notice that the motor amps are greatly reduced in this condition as the pump is not doing much work. This is why it is common practise to start a pump with a shut, or almost shut discharge valve.
RE: Basic pump operation
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RE: Basic pump operation
For example, in an air operated diaphragm pump, there are inlet and outlet check valves.
In a centrifugal pump, the answer is that it DOES go back from the discharge to the suction. But only a small amount does this.
RE: Basic pump operation
RE: Basic pump operation
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RE: Basic pump operation
RE: Basic pump operation
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RE: Basic pump operation
Centrifugal pumps...gerotor pumps...gear pumps...piston pumps.
Trying to anything other than crawl is too hazzardous.
Basic mechanics seperates negative and positive pressure.
Regards
Adrian