Page 27 - Know and Understand Centrifugal Pumps

Know and Understand Centrifugal Pumps

9 ATMOSPHERIC
PRESSURE
I

L4 I I DISCHARGE
DISCHARGE
HEAD
HEAD
SUCTION
SUCTION
I I
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Figure 1-6
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The total head is:
The work of the pump.

The measure of the pump's ability to raise the liquid to a given
height.
The measure of the pump's ability to develop a given discharge
pressure.
The discharge elevation minus the suction elevation.
The discharge head minus the suction head.
The discharge head plus the suction lift.

The discharge absolute pressure reading minus the suction absolute
pressure reading.

Suction head
The suction head is the available head at the suction nozzle of the
pump.

Discharge head
The discharge head is the vertical distance from the centerline of the
pump (this would be the shaft on a horizontal pump) to the level in the
discharge vessel.

Suction lift
Suction lift is negative suction head. It exists when the liquid level in
the suction vessel is below the centerline of the pump. The pump must
aspirate the liquid up from the suction vessel into the pump and then