1. What is a Fire Flow Formula Calculator?

Definition: This calculator estimates the fire flow rate (in gallons per minute) for firefighting systems based on the orifice flow equation.

Purpose: It helps fire protection engineers and designers determine the required water flow rate for fire suppression systems.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( Q \) — Flow rate (gallons per minute, GPM)
• \( C_d \) — Discharge coefficient (dimensionless)
• \( A \) — Area of the orifice (square feet, ft²)
• \( \Delta P \) — Pressure difference (pounds per square inch, psi)
• \( \rho \) — Density of the fluid (pounds per cubic foot, lb/ft³)

Explanation: The formula calculates the flow rate through an orifice based on the pressure difference and fluid properties.

3. Importance of Fire Flow Calculation

Details: Accurate flow rate estimation ensures proper fire suppression system design, adequate water supply, and compliance with fire safety codes.

4. Using the Calculator

Tips: Enter the discharge coefficient (default 0.61 for sharp-edged orifices), area, pressure difference, and fluid density (default 62.4 lb/ft³ for water). All values must be > 0.

5. Frequently Asked Questions (FAQ)

Q1: What is a typical discharge coefficient (C_d)?
A: For sharp-edged orifices, 0.61 is common. For rounded orifices, it may be 0.98, and for nozzles, 0.7-0.9.

Q2: How do I determine the area (A)?
A: For circular orifices, use \( A = \pi \times r^2 \) where r is the radius in feet.

Q3: What's the significance of the 448.83 factor?
A: This converts the result from cubic feet per second to gallons per minute (1 ft³/s = 448.83 GPM).

Q4: When would I change the fluid density (ρ)?
A: For fluids other than water at standard conditions, or for water at different temperatures.

Q5: How accurate is this calculation?
A: It provides theoretical maximum flow. Actual flow may be 5-10% less due to friction losses and other factors.