BHP = Q × P / (C × n)

Where:

BHP = Brake Horsepower in horsepower
Q = Flow Rate in gallons per minute
P = Pressure in pounds per square inch
n = Efficiency expressed as a decimal
C = A conversion factor depending on units of flow and pressure

 

Units Value of C
GPM / PSI 1714
GPM / Hd. Ft. 3960 / SG
Barrels per Day / PSI 58773
Barrels per Day / Hd. Ft. 135788 / SG
CFM / PSI 229.16
CFM / Hd. Ft. 529.45 / SG
Cubic Meters per Hour / PSI 6.4875
Cubic Meters per Hour / Hd. Ft. 14.989 / SG

* SG = Specific Gravity of the fluid

Horsepower [HP] = Flow Rate [GPM] × Pressure [PSI] / (C × Efficiency)

 

Example #1:

Flow Rate = 750 GPM
Pressure = 125 PSI
Efficiency = 78%

750 [GPM] × 125 [PSI] / (1714 × 0.78) = 70.12 HP

Example #2:

Flow Rate = 125,000 BBL/Day
Pressure = 798 Hd.Ft.
SG = 0.75
Efficiency = 81%

125,000 [BBL/Day] × 798 [Hd.Ft.] / {( 135,788 / 0.75) × 0.81} = 680.2 HP

These calculations and the information provided on this page is for reference only. Power Zone Equipment is not responsible for errors or incorrect caclulations when applied to real life projects. Please use this information with care. For engineering assistance and design of equipment systems, please contact Power Zone Equipment.

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