Calculate Pump Horsepower From Flow And Head

Pump Hydraulic Horsepower Formula:

\[ HP = \frac{GPM \times Head_{ft} \times SG}{3960 \times Efficiency} \]

Flow Rate (GPM):

GPM

Head:

feet

Specific Gravity (SG):

(unitless)

Efficiency:

decimal

Hydraulic Horsepower (HP):

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1. What Is Pump Hydraulic Horsepower?

Hydraulic horsepower represents the actual power delivered to the fluid by the pump. It's a crucial parameter in pump selection and system design, indicating the energy required to move fluid against system resistance.

2. How Does The Calculator Work?

The calculator uses the hydraulic horsepower formula:

\[ HP = \frac{GPM \times Head_{ft} \times SG}{3960 \times Efficiency} \]

Where:

\( HP \) — Hydraulic horsepower
\( GPM \) — Flow rate in gallons per minute
\( Head_{ft} \) — Total dynamic head in feet
\( SG \) — Specific gravity of the fluid
\( Efficiency \) — Pump efficiency as a decimal (0.0 to 1.0)
\( 3960 \) — Conversion constant

Explanation: This equation calculates the power required to move a specific flow rate against a given head, accounting for fluid density and pump efficiency.

3. Importance Of Hydraulic Horsepower Calculation

Details: Accurate hydraulic horsepower calculation is essential for proper pump selection, motor sizing, energy consumption estimation, and system efficiency analysis in various industrial and commercial applications.

4. Using The Calculator

Tips: Enter flow rate in GPM, head in feet, specific gravity (1.0 for water), and pump efficiency as a decimal (e.g., 0.75 for 75% efficiency). All values must be positive numbers.

5. Frequently Asked Questions (FAQ)

Q1: What is the difference between hydraulic HP and brake HP?
A: Hydraulic HP is the power delivered to the fluid, while brake HP is the power input to the pump shaft. Brake HP = Hydraulic HP / Efficiency.

Q2: Why is specific gravity important?
A: Specific gravity accounts for fluid density. Denser fluids require more power to pump at the same flow rate and head.

Q3: What is a typical pump efficiency range?
A: Pump efficiencies typically range from 50% to 85%, depending on pump type, size, and operating conditions.

Q4: Can this formula be used for all pump types?
A: Yes, this fundamental hydraulic horsepower formula applies to centrifugal, positive displacement, and other pump types.

Q5: How does head affect horsepower requirements?
A: Horsepower increases linearly with head - doubling the head doubles the horsepower requirement at constant flow.