1. What is Volume Flow Rate?

Definition: Volume flow rate measures the volume of fluid that passes through a given surface per unit time.

Purpose: This calculator helps engineers and technicians determine the flow rate in gallons per minute (GPM) based on velocity and cross-sectional area.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( Q \) — Volume flow rate (gallons per minute, GPM)
• \( V \) — Velocity (feet per second, ft/s)
• \( A \) — Cross-sectional area (square feet, ft²)
• 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 gallons per minute.

3. Importance of Flow Rate Calculation

Details: Accurate flow rate calculations are essential for designing piping systems, pumps, and fluid handling equipment.

4. Using the Calculator

Tips: Enter the fluid velocity in ft/s and the pipe's 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): 7.48052 × 60 = 448.8312.

Q2: How do I calculate cross-sectional area?
A: For circular pipes: A = π × (diameter/2)². For rectangular ducts: A = width × height.

Q3: What's a typical velocity for water in pipes?
A: Typically 2-8 ft/s, with 5 ft/s being common for many applications.

Q4: Can I use this for gases?
A: Yes, but note that gas flow rates are often measured in standard cubic feet per minute (SCFM).

Q5: How accurate is this calculation?
A: It provides theoretical maximum flow; actual flow may be less due to friction and other factors.