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Pump Efficiency Calculator

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Notes:

  • 3960 is the standard conversion factor for converting GPM × ft into hydraulic horsepower (HP) in Imperial units.
  • In Imperial units, efficiency is calculated using:
    Efficiency (%) = (3960 × GPM × Head in ft) ÷ (BHP × 746) × 100
  • In Metric units, efficiency is calculated using:
    Efficiency (%) = (9.81 × L/s × Head in m) ÷ (kW × 1000) × 100
    Flow is entered in LPM (liters per minute) and converted to L/s internally for the calculation.
  • The efficiency result is shown as a percentage and rounded to two decimal places.
  • These calculations assume the pumped liquid is clean water or a fluid with a specific gravity close to 1.0. Heavier or lighter fluids will affect actual power requirements and efficiency.
  • Brake Horsepower (BHP) is the actual power delivered to the pump shaft. In metric, this is entered directly in kilowatts (kW).
  • Pump efficiency values over 100% are not physically possible and indicate incorrect input data or unrealistic assumptions.

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