Pipe sizing tool.
Check velocity, straight-pipe pressure loss and friction head using the actual internal bore.
Know what
the result includes.
Size by the actual bore
The calculation uses Darcy–Weisbach, with an iterated Colebrook friction factor for turbulent flow and 64/Re for laminar flow. Pressure loss is withheld in the transitional range 2,300 ≤ Re < 4,000. The input is internal diameter; nominal sizes vary with material and wall thickness.
The example properties approximate clean water at 20°C. Temperature and glycol concentration change viscosity and density. Check these against the fluid supplier’s data. See the EPA EPANET hydraulic-method reference and NIST water-viscosity reference.
Friction head here covers only the straight length entered. It excludes fittings, valves, equipment, elevation requirements and the rest of the index circuit. It is not the pump duty.
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Calculations run in your browser. Engin does not save these inputs.
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