1. What is a Pipe Flow Rate Calculator?

Definition: This calculator determines the volumetric flow rate of liquid through a pipe in gallons per minute (GPM) based on flow velocity and pipe cross-sectional area.

Purpose: It helps engineers, plumbers, and fluid system designers properly size pipes and understand system flow characteristics.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( Q \) — Flow rate (gallons per minute)
• \( V \) — Flow velocity (feet per second)
• \( A \) — Cross-sectional area (square feet)
• \( 448.83 \) — Conversion factor (ft³/s to GPM)

Explanation: The formula converts the basic volumetric flow rate (velocity × area) from cubic feet per second to gallons per minute.

3. Importance of Flow Rate Calculation

Details: Accurate flow rate calculations ensure proper pipe sizing, maintain desired velocities, and prevent issues like excessive pressure drop or water hammer.

4. Using the Calculator

Tips: Enter the flow velocity in ft/s and the pipe's cross-sectional area in ft². For circular pipes, area = π × (diameter/2)².

5. Frequently Asked Questions (FAQ)

Q1: What's a typical flow velocity for water pipes?
A: Residential systems typically use 4-8 ft/s, while industrial systems may go up to 10-15 ft/s depending on application.

Q2: How do I calculate pipe cross-sectional area?
A: For circular pipes: A = π × r² where r is the radius in feet. Our Pipe Area Calculator can help with this calculation.

Q3: Why 448.83 as the conversion factor?
A: It converts cubic feet per second to gallons per minute (1 ft³/s = 448.83 GPM).

Q4: Does this work for any liquid?
A: Yes, but the formula assumes the liquid has similar properties to water. For viscous fluids, additional factors may be needed.

Q5: What if I know diameter instead of area?
A: First calculate area using diameter: A = π × (diameter/2)², then use that value in this calculator.