Hazen-Williams Head Loss due to Friction Equation

Written by Jerry Ratzlaff on . Posted in Fluid Dynamics

This head loss due to friction formula is used in Hazen-Williams equations.

 

Hazen-Williams Head Loss due to Friction Equation formulas

\(\large{ h_f = \frac { 4.73\; l_p \; \left( \frac {Q}{C} \right) ^{1.852} }{d^{4.87} }  }\)  (US units) 
\(\large{ h_f = 4.73  \left( \frac {Q}{C} \right) ^{1.852}  \frac{l_p}{d^{4.87}}   }\)  (US units) 
\(\large{ h_f = 10.7  \left( \frac {Q}{C} \right) ^{1.852}  \frac{l_p}{d^{4.87}}   }\)  (SI units)

Where:

 Units English Metric
\(\large{ h_f }\) = head loss due to friction \(\large{ft}\)  \(\large{m}\) 
\(\large{ Q }\) = 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 \(\large{in}\) \(\large{mm}\)
\(\large{ l_p }\) = lenght of pipe \(\large{ft}\) \(\large{m}\)

 

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Tags: Pipe Sizing Equations Head Equations Hazen-Williams Equations