The Hazen-Williams Formula is frequently used in the analysis of pressure pipe systems (such as water distribution networks and sewer force mains). The formula is as follows:
| |
Q |
= |
Discharge in the section (m 3 /s, cfs) |
| |
C |
= |
Hazen-Williams roughness coefficient (unitless) |
| |
A |
= |
Flow area (m 2 , ft. 2 ) |
| |
R |
= |
Hydraulic radius (m, ft.) |
| |
S |
= |
Friction slope (m/m, ft./ft.) |
| |
k |
= |
Constant (0.85 for SI units, 1.32 for US units). |
