eli5: explain the meaning behind “pumps create flow not pressure and resistance to flow creates pressure.”

Question

Isn’t this kind of the same thing as saying the pump creates the pressure?

In: 2

Answer 1

Pumps physically move fluid. They create flow. There’s nothing in the pump mechanism itself that creates pressure, they just move fluid around…if you leave the outlet open on a pump you’ll have full flow and zero (ambient) outlet pressure. It’s only by restricting the flow that you get pressure.