PVC pipe — Hazen-Williams headloss

This page covers headloss calculation for PVC pipe using the Hazen-Williams equation — the canonical pairing for Cold water, irrigation, sewer (gravity + pressure).

Pipe parameters — PVC

Hazen-Williams C-factor (new)

150

Hazen-Williams C-factor (aged)

140

Absolute roughness (ε)

5e-06 ft

Typical uses

Cold water, irrigation, sewer (gravity + pressure)

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.