# Hazen-Williams Flow through a Pressurized Pipe Equation

Written by Jerry Ratzlaff on . Posted in Fluid Dynamics

The Hazen-Williams Equation can be used for flow through an open channel or through a pressurized pipe.

## Hazen-Williams flow through a pressurized pipe Equation formulas

 $$\large{ p_d = \frac{4.52 \; Q^{1.852}} {C^{1.852} \; d^{4.8704}} }$$ (US units) $$\large{ p_d = \frac{10.67 \; Q^{1.852}} {C^{1.852} \; d^{4.8704}} }$$ (SI units)

### Where:

 Units English Metric $$\large{ p_d }$$ = pressure drop over the length of pipe $$\large{\frac{lbf}{in^2}}$$ $$\large{Pa}$$ $$\large{ Q }$$ = flow rate $$\large{\frac{ft^3}{sec}}$$ $$\large{\frac{m^3}{s}}$$ $$\large{ C }$$ = Hazen-Williams coefficient $$\large{dimensionless}$$ $$\large{ d }$$ = inside diameter of pipe $$\large{in}$$ $$\large{mm}$$