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The Pipe Sizing Calculator helps plumbing and mechanical engineers determine appropriate pipe diameters based on flow rate and velocity requirements. Calculate pipe sizes for water supply, gas distribution, and drainage systems.
Proper pipe sizing ensures adequate flow capacity while maintaining acceptable velocities and pressure drops. Oversized pipes waste materials and increase costs, while undersized pipes cause excessive pressure loss and noise.
Enter flow rate, desired velocity, and pipe type to calculate required pipe diameter. The calculator recommends standard pipe sizes and helps optimize pipe selection for water supply, gas, and drainage applications.
Features
Everything you need
- Pipe diameter calculations
- Flow rate and velocity inputs
- Water, gas, and drainage support
- Standard pipe size recommendations
- Velocity limit verification
- Pressure drop considerations
- Imperial and metric units
How it works
Simple workflow
- 1Enter required flow rate
- 2Specify desired velocity
- 3Select pipe type (water, gas, drain)
- 4Review calculated pipe diameter
- 5See recommended standard size
Use cases
Built for real-world scenarios
Water supply design
Size water supply pipes for residential and commercial plumbing systems.
Gas distribution
Determine gas pipe sizes for natural gas and propane distribution systems.
Drainage design
Size drainage pipes for sanitary and storm drainage systems.
System retrofitting
Evaluate existing pipe capacity and determine upgrade requirements.
FAQ
Frequently asked questions
Pipe Area = Flow Rate ÷ Velocity. Diameter = √(4 × Area ÷ π). For water: typical velocity 4-8 ft/s. For drainage: 2-4 ft/s minimum to prevent solids deposition.
Water supply: 4-8 ft/s (higher for mains, lower for branches). Gas: 10-30 ft/s depending on pressure. Drainage: 2-4 ft/s minimum. Higher velocities increase pressure drop and noise.
Standard sizes: 1/2", 3/4", 1", 1-1/4", 1-1/2", 2", 2-1/2", 3", 4", 6", 8", 10", 12". The calculator recommends the next standard size up from calculated diameter.
Smaller pipes create higher velocities and greater pressure drop (head loss). Pressure drop increases with velocity squared, so doubling velocity quadruples pressure drop. Proper sizing balances flow needs with pressure loss.
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