1. What is Flow Calculation for Gases?

Definition: This calculator estimates the flow rate of gases in gallons per minute (GPM equivalent) based on velocity and cross-sectional area.

Purpose: It helps engineers and technicians determine gas flow rates in piping systems and ventilation applications.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( Q \) — Flow rate (gallons per minute, GPM equivalent)
• \( V \) — Velocity of the gas (feet per second, ft/s)
• \( A \) — Cross-sectional area (square feet, ft²)
• 448.83 — Conversion factor to get GPM equivalent

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 ensure proper system design, efficient operation, and safety in gas handling systems.

4. Using the Calculator

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

5. Frequently Asked Questions (FAQ)

Q1: Why is there a conversion factor of 448.83?
A: This converts cubic feet per second to gallons per minute (1 ft³/s = 448.83 GPM).

Q2: What's a typical gas velocity in piping systems?
A: For compressed air, typical velocities range from 20-40 ft/s in mains and 50-120 ft/s in branch lines.

Q3: How do I calculate cross-sectional area?
A: For circular pipes: \( A = \pi \times (D/2)^2 \) where D is diameter in feet.

Q4: Does this work for liquids too?
A: Yes, the same formula applies to liquid flow calculations.

Q5: How accurate is this calculation?
A: It provides theoretical flow rates. Actual flow may vary due to friction, temperature, and pressure effects.