1. What is the Gravity Pipe Velocity Formula?

The velocity formula calculates the flow velocity in a pipe based on flow rate and cross-sectional area. It is essential for designing and analyzing gravity flow systems in various engineering applications.

2. How Does the Calculator Work?

The calculator uses the velocity formula:

Where:

• \( V \) — Velocity (ft/s)
• \( Q \) — Flow rate (gpm)
• \( A \) — Cross-sectional area (sq ft)
• 448.83 — Conversion factor

Explanation: The formula converts flow rate in gallons per minute to velocity in feet per second, accounting for unit conversions through the constant factor.

3. Importance of Velocity Calculation

Details: Calculating flow velocity is crucial for proper pipe sizing, ensuring adequate flow rates, preventing sediment deposition, and maintaining system efficiency in gravity-fed systems.

4. Using the Calculator

Tips: Enter flow rate in gallons per minute (gpm) and cross-sectional area in square feet (sq ft). All values must be valid positive numbers.

5. Frequently Asked Questions (FAQ)

Q1: Why is the conversion factor 448.83?
A: This factor converts gallons per minute to cubic feet per second (7.48052) and accounts for the area unit conversion (1 ft² = 144 in²).

Q2: What are typical velocity ranges in gravity pipes?
A: Typically 2-5 ft/s for wastewater, 3-10 ft/s for water supply. Too low causes sedimentation; too high increases friction losses.

Q3: How do I calculate cross-sectional area?
A: For circular pipes: A = π × (diameter/2)². Convert to square feet by dividing by 144 if diameter is in inches.

Q4: Does this work for pressurized systems?
A: Yes, the formula works for both gravity and pressurized systems, as it's based on continuity equation principles.

Q5: When should I be concerned about velocity?
A: High velocities (>10 ft/s) can cause erosion, water hammer, and excessive noise. Low velocities (<2 ft/s) may allow sediment accumulation.