1. What Is Flow GPM?

Definition: Flow GPM (Gallons Per Minute) measures the volumetric flow rate of liquids through a pipe or channel.

Purpose: This calculator helps engineers, plumbers, and irrigation specialists determine liquid flow rates in various 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 hydraulic efficiency in piping systems.

4. Using the Calculator

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

5. Frequently Asked Questions (FAQ)

Q1: What's the 448.83 conversion factor?
A: It converts cubic feet per second to gallons per minute (1 ft³/s = 448.83 GPM).

Q2: How do I find the cross-sectional area?
A: For circular pipes: \( A = \pi \times r² \) where r is the radius in feet.

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

Q4: Does this work for any liquid?
A: Yes, but the velocity should be appropriate for the specific liquid's viscosity.

Q5: How accurate is this calculation?
A: It provides theoretical flow; actual flow may vary due to friction, elevation, and pipe roughness.