Pressure Loss & Velocity in Piping

Friction loss, velocity, Reynolds number and regime at a given size and flow, for five fluids.

Unit system

Inputs

FluidPipe sizeScheduleMass flow

Pipe length

Line pressure (absolute)

Temperature

Ignored for saturated steam — the temperature follows from the pressure.Pipe roughnessElevation change

Positive when rising. Negligible on steam, but on water it can dwarf the friction.

Total pressure loss

0.07609bar a

Flow velocity

13.15m/s

Velocity check	Within the recommended limit (40 m/s)
Friction component	0.07609 bar a
Elevation component	0 bar a
Reynolds number	447,039
Flow regime	Turbulent
Friction factor λ	0.01750
Density	5.145 kg/m³
Volume flow	388.7 m³/h
Loss per metre	0.000761 bar a

This is STRAIGHT pipe friction. Bends, valves and strainers are not included; use the Pressure Drop Analysis screen for an element chain.
Density comes from the same source as the rest of the package (IAPWS-IF97 / ideal gas). Viscosity is a correlation; since Reynolds enters friction to the 0.25 power, a 1 % deviation moves the result by half a per mille.
The fluid is treated as incompressible. If the loss exceeds about ten percent of the line pressure, split the line into sections — the density changes along it.

A PDF carrying the inputs, results, assumptions and the source. A one-time code is sent to your address.

Results are for engineering pre-assessment and are not a product selection commitment. Final responsibility rests with the user.