Page 97 - Know and Understand Centrifugal Pumps

Know and Understand Centrifugal Pumps

A

0 6 10
GPM
Figure 7-3
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impossible to operate
between shut-off head
The pump can be to
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,

assembled parts and toleranc
the pump.

Pump efficiency
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Let’s talk about the pump efficiency. Imagine a small pump connected
to a garden hose squirting a stream of water across the lawn. You could
direct the flow from the hose up into the air at about a 45-degree
angle, and the stream would arc upward and attain its best distance of
reach from the nozzle or launch point. The stream of water would
attain a specific height into the air and a specific distance. The efficiency
curve of a pump is seen as the trajectory or arc of a stream of water.
When squirted from a hose, the elevation that attains the best distance,
when plotted onto the pump curve, is called the best efficiency point
(REP). On the pump curve, it is seen as in Figure 74.