Pressure Loss

Pressure loss, abbreviated as \(\Delta P\), also called pressure drop, is the difference in pressure between two points, usually caused by friction resistance in the pipe, but moisture can also affect it.

 

Pressure Loss formula
\(\large{ P_l =  \mu  \; \left( \frac{ l_p  }{ d_h } \right) \; \left( \rho\;\frac{ v^2 }{ 2 } \right) }\)
Symbol	English	Metric
\(\large{  P_l }\) = pressure loss	\(\large{\frac{lbf}{in^2}}\)	\(\large{Pa}\)
\(\large{ \rho }\)   (Greek symbol rho) = density	\(\large{\frac{lbm}{ft^3}}\)	\(\large{\frac{kg}{m^3}}\)
\(\large{ \mu }\)  (Greek symbol mu) = friction coefficient	\(\large{ dimensionless }\)
\(\large{ d_h }\) = hydraulic diameter	\(\large{ ft }\)	\(\large{ m }\)
\(\large{ l }\) = lenght of pipe	\(\large{ ft }\)	\(\large{ m }\)
\(\large{ v }\) = velocity of fluid	\(\large{\frac{ft}{sec}}\)	\(\large{\frac{m}{s}}\)