# Head Friction Loss in Fittings and Valves

Written by Jerry Ratzlaff on . Posted in Fluid Dynamics

Head loss, abbreviated as $$h_f$$, is the pressure drop caused by fittings and valves.

## Formulas that use Head Friction Loss in Fittings and Valves

 $$\large{ h_f = K \; \frac{v^2}{2 \; g} }$$

### Where:

$$\large{ h_f }$$ = head loss frictional resistance

$$\large{ g }$$ = gravitational constant

$$\large{ K }$$ = loss coefficient for fittings and valves

$$\large{ v }$$ = velocity of flow