What is the difference between a pump's head and its flow rate?

What is the difference between a pump's head and its flow rate?

• A. Head is the pressure against which the pump must push (height/pressure), while flow rate is the volume moved per time.
• B. Head is the flow rate; flow rate is pressure.
• C. Head is maximum flow; flow rate is energy used.
• D. Head and flow rate are the same.

Answer: (A)

Head represents the pressure energy the pump has to overcome to move the fluid to a certain height or against backpressure. It’s like how high or how hard the pump can push the liquid. Flow rate, on the other hand, is how much liquid is moved each second or minute—volume per unit time. So a pump can generate significant head (high pressure) but still deliver a small flow if the discharge is restricted, and vice versa. In pump curves, increasing head usually means the flow rate falls. That’s why the difference is that head is the pressure/energy the pump must overcome, while flow rate is the amount of liquid moved over time.

Head represents the pressure energy the pump has to overcome to move the fluid to a certain height or against backpressure. It’s like how high or how hard the pump can push the liquid. Flow rate, on the other hand, is how much liquid is moved each second or minute—volume per unit time.

So a pump can generate significant head (high pressure) but still deliver a small flow if the discharge is restricted, and vice versa. In pump curves, increasing head usually means the flow rate falls. That’s why the difference is that head is the pressure/energy the pump must overcome, while flow rate is the amount of liquid moved over time.