Aquatec 8800 series Flow vs Pressure question

[jimmol]

I am using an Aquatec 8852 diaphragm pump for pumping from holding tanks to buckets and some vacuum work. I was looking at the specs sheet at http://www.freshwatersystems.com/specifications/8800_RO_Booster_Pump_24Vac.pdf and noticed that the flow increases as the pressure goes down. Opposite seems of a hose attached to the house water.

Since I know nothing about pumps, or fluid hydraulics for that matter, I was wondering if some could explain how this can be?

I assume this might mean if we want a higher flow to fill the buckets faster, we turn down the pressure. Would a higher flow/lower pressure also equal more vacuum?

Thanks in advance for taking the time to answer.

[maple flats]

That is correct. When the pump needs to generate more pressure to make the liquid move it looses GPM. When it is just open discharge (no restriction) it moves more GPM. In this case, you need to think of the pressure as a restriction to flow.

[village idiot]

It is just like a garden hose. When you put your thumb over the end of it the pressure will go up (it shoots out farther) but the flow (volume moved in 1 min) will go down.

[jimmol]

Thanks for the examples, it is clearer now.

[pennslytucky]

i have the same pump (8852) sitting on the shelf. how did it work for you?