The Tool Box
Hydronic sizing
Pump Head Loss Calculator
Darcy-Weisbach friction losses plus fittings and pump shaft power for a straight run. Use to validate designer pump selections and sanity-check pressure drop calculations.
Inputs
Result
Velocity1.27 m/s
Reynolds number111688
Friction factor f0.0199
Friction head loss1.97 m
Minor losses0.50 m
Total head loss2.47 m
Shaft power0.35 kW
How this works
Friction head is computed with the Swamee-Jain explicit approximation of the Colebrook equation. Minor losses from fittings are the sum of K × v² / 2g.
Shaft power = ρ · g · Q · H / η. A typical wet-rotor circulator sits at η = 55-65%, a well selected end-suction centrifugal at η = 70-82%.
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