How to get from pump flow rate to pressure change

1. Nov 8, 2012

zzinfinity

Hi,
Essentially what I need is a pump that will pump 40 gallons of water per hour to a height of 8 feet. Ignoring pressure losses in the lines (for now) I used the bernouli equation to determine that I need a pressure change of 3.44 psi in my pump. I found these pumps that look suitable but all list a max head far lower than the 8 feet I need. http://www.drsfostersmith.com/product/prod_display.cfm?pcatid=21414

I was thinking maybe just use one with a higher volume flow to compensate for the head loss. Maybe the 100 gph one? Is there a way to determine exactly what I need? Thanks!

2. Nov 8, 2012

SteamKing

Staff Emeritus
If the pump cannot deliver a head greater than 8', increasing the flow will not compensate. Find a pump which can deliver at least 8' of head, or re-design the piping system to reduce the head loss.

3. Nov 8, 2012

zzinfinity

Fascinating. Fluid mechanics has always baffled me. Thanks!

4. Nov 8, 2012

5. Nov 8, 2012

zzinfinity

Out of curiosity, is there a fundamental reason why a pump that can pump 200 gph to a height of 5 feet, can't also pump 100 gph to a height of 10 feet?