reverse flow through a pump

Replies

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  Ramani Aswath

  This can happen in a idling centrifugal pump, which will not affect the pump. It can happen in a peristaltic pump if run in reverse, which also will not affect. In other pumps it cannot happen.
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  Don Ross

  I run a centrifugal pump back wards on a cooling system in the winter time to keep the water moving so as to not freeze the heat exchanger outside. Then when the cooling load increases and the valves shift from bypass to full flow I swap them to a forward motion. The pumps over amp due to a poor design in the bypass piping so I have to do it. They will pump water running backwards.The amperage drops about 15%. Weird but true.
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  Ramani Aswath

  Don Ross

  The amperage drops about 15%. Weird but true.

  A centrifugal pump has a progressively enlarging chamber. Rotating the impelletr in reverse still spins the water and the centrifugal force will pump it out. However, the now forward swept impeller and the reverse direction of rotation leads to poorer performance. The lesser head leads to lesser amps.
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  Don Ross

  The reversing of the direction of motor rotation is one thing but his question is in the direction of water flow. That will not happen if the pump is running. Other than that it is just along for the ride and when off it should rotate in the direction of the flow of water. But I can't not see that app. I've seen one pump over take and reverse the flow of another. And actually come to a dead stop in their flow against each others head. I lost a 50 hp compressor because of that..
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  NAVATHE SACHIN

  Generally in two stage pumps in order to create more vacuum in pump,discharge port is connected to suction port through cross manifold see the figure.
• 

  Ramani Aswath

  N.SACHIN

  Generally in two stage pumps in order to create more vacuum in pump,discharge port is connected to suction port

  However, in each stage the flow is always from suction to delivery. In a multistage it is actually so many pumps in series.
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  Don Ross

  Yea pumps,,,,fun let's talk about pumps. Be very specific a s to the type of pump and application. Don't just talk generic. specifics guys.
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  Don Ross

  It's like the big bang everyone is a specialist about the internal combustion engine but no one can work on it. Ever lay on a pump with your screw driver in your ear listening to the sound of the bearings,,,, hmmm Lay on a 50 hp pump and tell the customer what you think he should do lol
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  Don Ross

  Ever have two 50 hp pumps in parallel running side by side and surging between each other. lol life is living it not just text books.