The term for a pump where discharge volume changes with head is which?

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Multiple Choice

The term for a pump where discharge volume changes with head is which?

Discharge that changes with head comes from pumps that don’t deliver a fixed amount of fluid per cycle. In nonpositive-displacement pumps, the flow depends on the system head: as backpressure (head) increases, the discharge decreases, and when head drops, more fluid is discharged. This category includes common centrifugal pumps, where the pump curve shows lower flow at higher head and higher flow at lower head. In contrast, positive-displacement pumps deliver a nearly fixed volume per cycle, so their discharge stays relatively constant regardless of head until limits are reached. Rotary-displacement and diaphragm pumps are typical examples of positive-displacement types. So, the term describing a pump whose discharge volume changes with head is nonpositive-displacement.

Discharge that changes with head comes from pumps that don’t deliver a fixed amount of fluid per cycle. In nonpositive-displacement pumps, the flow depends on the system head: as backpressure (head) increases, the discharge decreases, and when head drops, more fluid is discharged. This category includes common centrifugal pumps, where the pump curve shows lower flow at higher head and higher flow at lower head.

In contrast, positive-displacement pumps deliver a nearly fixed volume per cycle, so their discharge stays relatively constant regardless of head until limits are reached. Rotary-displacement and diaphragm pumps are typical examples of positive-displacement types.

So, the term describing a pump whose discharge volume changes with head is nonpositive-displacement.

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