1. What is the Flow Rate Formula?

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

Purpose: It helps engineers, plumbers, and fluid system designers determine the flow rate in piping systems.

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 (ft³/s to GPM)

Explanation: The velocity multiplied by area gives flow in ft³/s, 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.

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 converts cubic feet per second to gallons per minute (1 ft³/s = 448.83 GPM).

Q2: How do I calculate pipe cross-sectional area?
A: For circular pipes: \( A = \pi \times (D/2)^2 \) where D is diameter in feet.

Q3: What's a typical velocity for water in pipes?
A: 2-5 ft/s for supply lines, 5-10 ft/s for drainage systems.

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

Q5: How does pipe material affect flow rate?
A: Material affects friction loss but not this basic calculation - use Darcy-Weisbach for detailed analysis.