1. What is a Fire Hose Friction Loss Calculator?

Definition: This calculator estimates the pressure loss due to friction in fire hoses based on the flow rate, hose length, and friction coefficient.

Purpose: It helps firefighters and fire protection engineers determine the pressure needed to maintain adequate water flow through hoses.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( FL \) — Friction loss (psi)
• \( C \) — Friction loss coefficient (depends on hose type)
• \( Q \) — Flow rate (gallons per minute)
• \( L \) — Hose length (feet)

Explanation: The formula accounts for the quadratic relationship between flow rate and friction loss, scaled by hose length and material characteristics.

3. Importance of Friction Loss Calculation

Details: Proper friction loss estimation ensures adequate water pressure at the nozzle, which is critical for firefighting effectiveness and safety.

4. Using the Calculator

Tips: Enter the friction coefficient (typical values: 8-24), flow rate in gpm, and hose length in feet. All values must be > 0.

5. Frequently Asked Questions (FAQ)

Q1: What are typical friction coefficients for fire hoses?
A: Common values are 8 for 5" hose, 15 for 3" hose, and 24 for 1¾" hose. Check manufacturer specifications.

Q2: Why does friction loss increase with the square of flow rate?
A: This reflects the turbulent flow regime in fire hoses where energy loss increases exponentially with velocity.

Q3: How does hose diameter affect friction loss?
A: Smaller diameter hoses have significantly higher friction loss at the same flow rate compared to larger hoses.

Q4: Should I include nozzle pressure in my calculations?
A: No, this calculator only determines friction loss. Add nozzle pressure (typically 50-100 psi) to get total required pump pressure.

Q5: How accurate is this calculation?
A: It provides a good estimate for new, clean hoses. Actual loss may vary with hose age, condition, and elevation changes.