1. What is Water Flow Rate Measurement?

Definition: This calculator measures water flow rate in gallons per minute (GPM) using velocity and cross-sectional area.

Purpose: It helps engineers, plumbers, and irrigation specialists determine water flow through pipes, channels, or other conduits.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( Q \) — Flow rate (gallons per minute)
• \( V \) — Water 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 volumetric flow in cubic feet per second, which is then converted to GPM.

3. Importance of Flow Rate Calculation

Details: Accurate flow rate measurement ensures proper system design, efficient water distribution, and compliance with regulations.

4. Using the Calculator

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

5. Frequently Asked Questions (FAQ)

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

Q2: How do I measure velocity?
A: Use flow meters or calculate from pressure drop using Bernoulli's equation.

Q3: What's a typical pipe flow velocity?
A: Residential systems: 4-8 ft/s, industrial: up to 10 ft/s depending on application.

Q4: How to calculate pipe area?
A: \( A = \pi \times r² \) where r is pipe radius in feet.

Q5: Can this be used for other liquids?
A: Yes, but density differences may require adjustment of the conversion factor.