1. What is a Fire Hose Flow Calculator?

Definition: This calculator estimates the water flow rate through a fire hose based on the hose diameter, pressure, and a coefficient.

Purpose: It helps firefighters and emergency responders determine the water flow capacity of their hoses under different pressure conditions.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( Q \) — Flow rate (gallons per minute)
• \( c \) — Coefficient (dimensionless, typically 0.97 for smooth bore nozzles)
• \( d \) — Hose diameter (inches)
• \( P \) — Pressure (psi)

Explanation: The flow rate increases with the square of the hose diameter and with the square root of the pressure.

3. Importance of Flow Rate Calculation

Details: Accurate flow rate estimation ensures proper water supply for firefighting, helps select appropriate pump sizes, and maintains effective fire suppression.

4. Using the Calculator

Tips: Enter the coefficient (default 0.97), hose diameter in inches, and pressure in psi. All values must be > 0.

5. Frequently Asked Questions (FAQ)

Q1: What affects the coefficient value?
A: The coefficient depends on hose material, age, and nozzle type (0.97 for smooth bore, 0.74-0.95 for fog nozzles).

Q2: How does diameter affect flow rate?
A: Flow rate increases with the square of diameter - doubling diameter quadruples flow at same pressure.

Q3: Why square root of pressure?
A: Flow is proportional to velocity, which is proportional to the square root of pressure according to Bernoulli's principle.

Q4: What's a typical fire hose diameter?
A: Common sizes are 1.5", 1.75", 2.5", and 3" diameters.

Q5: What pressures are typical in firefighting?
A: Standard operating pressures range from 50 psi to 300 psi depending on application.