1. What is Flow Rate vs Volumetric Flow Rate?

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

Purpose: It helps engineers and technicians determine fluid flow rates in pipes and channels for various applications.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( Q \) — Flow rate (GPM)
• \( V \) — Velocity (ft/s)
• \( A \) — Cross-sectional area (ft²)
• 448.83 — Conversion factor (ft³/s to GPM)

Explanation: The velocity is multiplied by the cross-sectional area to get volumetric flow in ft³/s, then converted to GPM.

3. Importance of Flow Rate Calculation

Details: Accurate flow rate calculations are essential for pipe sizing, pump selection, and system design in water supply, HVAC, and industrial processes.

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 difference between flow rate and velocity?
A: Velocity is speed (ft/s), while flow rate is volume per time (GPM). Flow rate = Velocity × Area.

Q2: Why 448.83 conversion factor?
A: It converts ft³/s to GPM (1 ft³/s = 448.83 GPM).

Q3: How do I find cross-sectional area?
A: For circular pipes: A = π × (diameter/2)². For rectangular channels: A = width × height.

Q4: What's a typical water velocity in pipes?
A: Domestic water: 4-8 ft/s. HVAC: 2-4 ft/s. High-pressure systems: up to 15 ft/s.

Q5: Can this be used for gases?
A: Yes, but gas flow calculations often require additional factors for compressibility.