Pump Discharge Pressure (PDP) = Nozzle Pressure (NP) + Friction Loss (FL) of hoselay ± Head Pressure (HP)
GPM (Gallons Per Minute) and NP:
Forester
3/16 tip: 7 gpm (50 psi NP)
3/8 tip: 30 gpm (50 psi NP)
Variable Pattern (Adjustable Barrel)
1 inch: 20 gpm (100 psi NP)
1½ inch: 60 gpm (100 psi NP)
FL for 1″ hose:
10 gpm = 3 psi per 100 ft.
20 gpm = 10 psi per 100 ft.
30 gpm = 23 psi per 100 ft.
FL for 1½” hose:
20 gpm = 1 psi per 100 ft.
30 gpm = 3 psi per 100 ft.
60 gpm = 13 psi per 100 ft.
HP: Add or subtract 1 psi for every 2 foot elevation change.
Gallons of water to fill 100 feet of hose:
¾” hose ≈ 2 gals.
1″ hose ≈ 4 gals.
1½” hose ≈ 9 gals.
Maximum effective lift for drafting = 22 feet at sea level, 14 feet at 8,000 ft. elevation.
Loss of 1 foot draft per 1000 feet elevation.
Use check and bleeder valve on pump discharge when pumping uphill to prevent back flow into the pump.
A parallel hose lay will have ¼ the friction loss of a single hoselay.