1. What is a Pump Horsepower Calculator?

Definition: This calculator determines the required horsepower for a pump based on flow rate, head pressure, fluid density, and pump efficiency.

Purpose: It helps engineers and technicians properly size pumps for various fluid transfer applications.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( HP \) — Pump horsepower
• \( Q \) — Flow rate (gallons per minute, GPM)
• \( H \) — Head (feet of fluid)
• \( \rho \) — Fluid density (pounds per gallon, lb/gal)
• \( \eta \) — Pump efficiency (decimal, 0-1)

Explanation: The formula calculates the power required to move a specific volume of fluid against a given pressure head, accounting for pump efficiency.

3. Importance of Pump Horsepower Calculation

Details: Proper horsepower calculation ensures pumps are correctly sized for the application, preventing underpowered or overpowered systems.

4. Using the Calculator

Tips: Enter the flow rate in GPM, head in feet, fluid density (default 8.34 lb/gal for water), and pump efficiency (default 0.85). All values must be > 0.

5. Frequently Asked Questions (FAQ)

Q1: What is the 3960 constant in the formula?
A: It's a conversion factor that combines various unit conversions to give horsepower directly from the input units.

Q2: What's a typical pump efficiency value?
A: Most pumps operate between 70-90% efficiency (0.7-0.9). High-efficiency pumps may reach 95%.

Q3: How do I determine the head pressure?
A: Head is the vertical distance the fluid must be pumped plus friction losses in the piping system.

Q4: What if I'm pumping something other than water?
A: Adjust the density value accordingly (e.g., 7.48 lb/gal for gasoline, 9.3 lb/gal for seawater).

Q5: Should I add a safety factor?
A: Yes, it's common to add 10-20% to the calculated horsepower for safety margins and future needs.