HP=GPMXPSI/1714 where 1714 is 100% efficient and theoretical. PSI required is about (varies by altitude) .42 psi/foot lift. 12000 gallons in an hour
or 200 gpm, let's assume 425 foot total lift (425X.42) = 180 psi (static) plus 50 psi to lift and accelerate the volume gives you 200 X 230/1714 (theo) or
about 26.8 hp (theoretical). You'd figure the pump efficiency (Hale firepump) at about 92% volumetric and 90% mechanical or about 83% overall. Factor
that into our 26.8 hp, or 26.8/.83 = 32.3 hp. That's the pump side, we've got the pressure drop in what could be 1200 feet of 3" pipe, @200 gpm that adds about
60 psi, add a few elbows (+15 psi) and you've got 75 psi drop just for the pipe at 200 gpm. So required horsepower is 230 (flow psi) + 75 (pipe drop) X
200 gpm= 1714/actual efficiency OR 42.8 real honest horsepower at the pump. So, John's hour fill would have a minimum of 43 real horsepower and with
the altitude correction you'd most likely need a 50 hp prime mover.
Edited 1 time(s). Last edit at 10/18/2017 04:17PM by rehunn.