HDPE pipe ā Darcy-Weisbach headloss
This page covers headloss calculation for HDPE pipe using the Darcy-Weisbach equation ā the canonical pairing for Trenchless install, gas, slip-line rehab.
Pipe parameters ā HDPE
- Hazen-Williams C-factor (new)
- 150
- Hazen-Williams C-factor (aged)
- 145
- Absolute roughness (ε)
- 5e-06 ft
- Typical uses
- Trenchless install, gas, slip-line rehab
Darcy-Weisbach method
Universal ā works for any fluid + any flow regime (laminar, transitional, turbulent).
Formula
h_f = f · (L/D) · (V² / 2g)
Limitations
Requires the friction factor f, which depends on Reynolds number and relative roughness ā typically evaluated via the Colebrook equation or Moody chart.