Hazen-Williams Pipe Hydraulics

Flow velocity and head loss of water pipes by the Hazen-Williams formula (C = 140 / 130 / 100).

Pipe inputs

Velocity limits by nominal size: DN15–20 ≤ 1.0, DN25–40 ≤ 1.2, DN50–70 ≤ 1.5, ≥ DN80 ≤ 1.8 m/s.

Pipe material

Design flow Q (L/s)

Calculated diameter d (mm)

Pipe length L (m)

Velocity v

—

m/s

Head loss i

—

mm/m

Total head loss

—

Velocity limit check

—

i = (1000·4^3.0185 / (0.849·π^1.8519)) · (0.001·Q/C)^1.8519 · (d/1000)^−4.8704

For a preselected diameter, velocity v = Q/(1000·A); automatic diameter selection from economic velocities can be applied per design flow.