1. What is a Volume Flow Rate Calculator?

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

Purpose: It helps engineers, plumbers, and fluid system designers determine flow rates in pipes and channels.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( Q \) — Volume flow rate (gallons per minute)
• \( V \) — Fluid 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 multiplied by area gives flow in cubic feet per second, which is then converted to GPM.

3. Importance of Flow Rate Calculation

Details: Accurate flow rate calculations ensure proper system design, pump sizing, and pipe diameter selection for efficient fluid transport.

4. Using the Calculator

Tips: Enter the fluid velocity in ft/s and cross-sectional area in ft². All values must be > 0.

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) to convert ft³/s to GPM.

Q2: How do I measure cross-sectional area?
A: For circular pipes: \( A = \pi \times r² \). For rectangular ducts: \( A = width \times height \).

Q3: What's a typical velocity for water in pipes?
A: Typically 4-8 ft/s for supply lines, 2-5 ft/s for drainage to prevent noise and erosion.

Q4: Can I use this for gases?
A: Yes, but gas flow rates are often measured in CFM (cubic feet per minute) instead of GPM.

Q5: How does pipe diameter affect flow rate?
A: Flow rate increases with the square of pipe diameter (double diameter = 4x flow at same velocity).