Ductile Iron pipe — Hazen-Williams headloss

This page covers headloss calculation for Ductile Iron pipe using the Hazen-Williams equation — the canonical pairing for Water mains, sewage force mains.

Pipe parameters — Ductile Iron

Hazen-Williams C-factor (new)

130

Hazen-Williams C-factor (aged)

100

Absolute roughness (ε)

0.00085 ft

Typical uses

Water mains, sewage force mains

Hazen-Williams method

Water-only, turbulent flow, 40-75°F. The default choice for municipal and irrigation work.

Formula

h_f = 10.67 · L · (Q/C)^1.852 / D^4.87  (SI units)

Limitations

Inaccurate for non-water fluids, very cold or hot temperatures, and laminar flow.