GIFSQ Tools · Module 17 — Food Processing, Thermal Engineering & Utilities · Tool 336 of 500
Work out the hydraulic and shaft power a pump needs from the flow rate, total head, fluid density and pump efficiency.
Try sample values — fills the form with the worked example below.
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Hydraulic power (kW)
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Shaft power (kW)
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Head pressure (kPa)
Equation: Hydraulic power P = ρ × g × Q × H, with Q in m³/s and g = 9.81 m/s²; shaft power = hydraulic power ÷ efficiency; head pressure = ρ × g × H.
Method: Standard pump power equation from Bernoulli’s principle, as used in food process engineering (Heldman and Singh) and pump handbooks.
Assumptions: steady, incompressible flow; the stated head already includes static lift plus friction and minor losses; efficiency is the pump efficiency alone.
Limitations: motor efficiency is not included — divide again by motor efficiency for electrical input power; viscous fluids need a viscosity correction to the pump curve.
Rounding: powers to 3 decimal places, pressure to 1; intermediates unrounded.
This is a calculation aid, not a laboratory report — confirm against your accredited method before citing a value.
Method: Standard pump power equation from Bernoulli’s principle, as used in food process engineering (Heldman and Singh) and pump handbooks.
Assumptions: steady, incompressible flow; the stated head already includes static lift plus friction and minor losses; efficiency is the pump efficiency alone.
Limitations: motor efficiency is not included — divide again by motor efficiency for electrical input power; viscous fluids need a viscosity correction to the pump curve.
Rounding: powers to 3 decimal places, pressure to 1; intermediates unrounded.
This is a calculation aid, not a laboratory report — confirm against your accredited method before citing a value.
Worked example: 10 m³/h against 20 m of head, water at 1000 kg/m³, 65% efficiency: hydraulic power = 0.545 kW, shaft power = 0.838 kW, head pressure = 196.2 kPa.
Enter values above to see results.
Total head = static lift + friction loss + minor losses + pressure head; measure or calculate each part before sizing the pump. Tool 336 of 500 — GIFSQ
