Flow Information
Gallons per minute
Affects velocity limits
Recommended Pipe Sizes
About Pipe Sizing
Formula: Velocity (ft/s) = 0.408 × Flow Rate (GPM) / Pipe Diameter² (inches)
Velocity Guidelines:
- Residential Water: Maximum 8 ft/s, optimal 4-6 ft/s
- HVAC Systems: Optimal 3-4 ft/s (heating/chilled water)
- Commercial: Maximum 8 ft/s, optimal 5-7 ft/s
Why Velocity Matters: Too high velocity causes noise, erosion, and pressure loss. Too low velocity can lead to sediment buildup and poor system performance.
Common Pipe Sizes Reference
Typical Flow Rates:
- Bathroom Faucet: 1.5-2.5 GPM
- Kitchen Faucet: 2.0-2.5 GPM
- Shower: 2.0-2.5 GPM
- Toilet: 3.0-5.0 GPM (flush)
- Washing Machine: 4.0-5.0 GPM
- Dishwasher: 2.0-3.0 GPM
- Garden Hose: 5.0-10.0 GPM