1. What is a Hose Monster Fire Hydrant Calculator?

Definition: This calculator estimates the flow rate from a fire hydrant using the Hose Monster formula, which considers discharge coefficient, outlet diameter, and pitot pressure.

Purpose: It helps firefighters and water system engineers determine hydrant flow capacity for firefighting operations and system design.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( Q \) — Flow rate (gallons per minute)
• \( c \) — Discharge coefficient (dimensionless, typically 0.9)
• \( d \) — Outlet diameter (inches, typically 2.5")
• \( P \) — Pitot pressure (psi)

Explanation: The formula calculates flow based on hydrant outlet characteristics and measured pressure.

3. Importance of Hydrant Flow Calculation

Details: Accurate flow estimation ensures adequate water supply for firefighting and helps identify potential system deficiencies.

4. Using the Calculator

Tips: Enter the discharge coefficient (default 0.9), outlet diameter (default 2.5 inches), and pitot pressure in psi. All values must be > 0.

5. Frequently Asked Questions (FAQ)

Q1: What is the Hose Monster method?
A: It's a standardized method for measuring fire hydrant flow using pitot pressure and known outlet characteristics.

Q2: Why 29.83 in the formula?
A: This constant combines unit conversions and accounts for water density to give flow in gallons per minute.

Q3: When would I change the discharge coefficient?
A: Adjust if using different outlet types (0.8 for older hydrants, 0.95 for smooth nozzles) or based on manufacturer specs.

Q4: How do I measure pitot pressure?
A: Use a pitot gauge in the center of the flow stream at the hydrant outlet.

Q5: What's a typical flow rate for fire hydrants?
A: Most hydrants deliver 500-1,500 gpm, but this varies by location and water system capacity.