1. What is a Key Hose Friction Loss Calculator?

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

Purpose: It helps firefighting professionals and hydraulic engineers determine the pressure drop in hoses for proper system design.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( \Delta P \) — Pressure loss (psi)
• \( C \) — Friction coefficient (dimensionless, e.g., 27 for some models)
• \( Q \) — Flow rate (gpm)
• \( L \) — Hose length (ft)

Explanation: The pressure loss increases with the square of the flow rate and linearly with hose length, scaled by the specific hose coefficient.

3. Importance of Friction Loss Calculation

Details: Accurate friction loss estimation ensures proper pump selection, adequate water pressure at nozzles, and efficient firefighting operations.

4. Using the Calculator

Tips: Enter the friction coefficient (default 27), flow rate in gpm, and hose length in feet. All values must be > 0.

5. Frequently Asked Questions (FAQ)

Q1: What's a typical friction coefficient for fire hoses?
A: Common values range from 24-30, with 27 being typical for many 1.75" attack hoses.

Q2: Why does flow rate have a squared relationship?
A: Friction loss increases exponentially with flow velocity due to turbulent flow conditions.

Q3: How does hose diameter affect the coefficient?
A: Larger diameter hoses generally have lower coefficients (less friction per foot).

Q4: Should I include fittings in the length?
A: No, this calculator is for straight hose lengths only. Fittings require additional loss calculations.

Q5: Does this account for elevation changes?
A: No, elevation changes require separate calculations (0.434 psi per foot of elevation gain).