1. What is a Gravity Fed Water Pipe Flow Calculator?

Definition: This calculator estimates the flow rate in gallons per minute (GPM) for water flowing through a pipe due to gravity.

Purpose: It helps engineers, plumbers, and irrigation specialists design gravity-fed water systems without pumps.

2. How Does the Calculator Work?

The calculator uses two formulas:

Where:

• \( V \) — Velocity of water (ft/s)
• \( g \) — Acceleration due to gravity (32.174 ft/s²)
• \( h \) — Head height (ft)
• \( Q \) — Flow rate (GPM)
• \( A \) — Cross-sectional area of pipe (ft²)

Explanation: First calculates the theoretical velocity from height, then converts to flow rate using pipe area.

3. Importance of Flow Rate Calculation

Details: Proper flow rate estimation ensures adequate water supply, correct pipe sizing, and efficient system design.

4. Using the Calculator

Tips: Enter the head height (vertical drop), pipe cross-sectional area, and gravity constant (default 32.174 ft/s²). All values must be > 0.

5. Frequently Asked Questions (FAQ)

Q1: How do I find pipe area?
A: For circular pipes: \( A = \pi \times (diameter/2)^2 \). Convert diameter to feet first.

Q2: Does this account for friction losses?
A: No, this is theoretical maximum. Actual flow will be less due to pipe friction and turbulence.

Q3: What's the conversion factor 448.83 for?
A: It converts ft³/s to GPM (1 ft³/s = 448.83 GPM).

Q4: Can I use this for non-water liquids?
A: Only if they have similar viscosity to water. The results won't be accurate for thicker liquids.

Q5: What's a typical head height for residential systems?
A: Typically 10-50 ft for gravity-fed systems, depending on terrain and water source elevation.