# Hazen-Williams Equation Flow through a Pressurized Pipe

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 Equation flow through a pressurized pipe formula

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

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

Where:

$$\large{ p_d }$$ = pressure drop over the length of pipe

$$\large{ Q }$$ = flow rate

$$\large{ C }$$ = Hazen-Williams Coefficient

$$\large{ d }$$ = pipe inside diameter (ID)