Hazen-Williams vs. Darcy-Weisbach: Head Loss Selection Criteria in Water Piping Design

A comparative analysis of empirical vs. fundamental friction loss equations across temperature, viscosity, and pipe roughness ranges.

Published by Dr. Elena Rostova, PE (Chief Process Hydraulicist) • August 1, 2026

Choosing between the empirical Hazen-Williams formula and the fundamental Darcy-Weisbach equation is critical in water distribution and industrial piping.