1. What is the Flow Rate Equation?

Definition: This calculator determines the volumetric flow rate (Q) in gallons per minute (GPM) based on fluid velocity and cross-sectional area.

Purpose: It helps engineers, plumbers, and fluid system designers calculate flow rates for pipes, channels, and other conduits.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( Q \) — Flow rate (gallons per minute)
• \( V \) — Velocity (feet per second)
• \( A \) — Cross-sectional area (square feet)
• 448.83 — Conversion factor (cubic feet to gallons and seconds to minutes)

Explanation: The velocity and area are multiplied, then scaled by the conversion factor to get GPM.

3. Importance of Flow Rate Calculation

Details: Accurate flow rate calculations ensure proper system design, pump sizing, and fluid delivery in piping systems.

4. Using the Calculator

Tips: Enter the velocity in ft/s and area in ft². Both values must be positive numbers.

5. Frequently Asked Questions (FAQ)

Q1: Why is the conversion factor 448.83?
A: It combines 7.48052 (gallons per cubic foot) and 60 (seconds per minute): 7.48052 × 60 ≈ 448.83.

Q2: What's a typical velocity for water in pipes?
A: Typically 2-8 ft/s for water, with 4-6 ft/s being common in residential plumbing.

Q3: How do I calculate pipe area?
A: For circular pipes: \( A = \pi \times (D/2)^2 \) where D is diameter in feet.

Q4: Can this be used for gases?
A: Yes, but gas flow rates are often measured in CFM rather than GPM.

Q5: What if I know diameter instead of area?
A: First calculate area using \( \pi r^2 \) where r is radius in feet.