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 formulas
\(\large{ \Delta P = \frac{f \; l \;v^2}{2 \; g \; d} }\) |
\(\large{ \Delta P = 2 \; f_f \left( \frac{ l }{ d } \right) \left( \rho \; \bar {v}^2 \right) }\) |
Where:
Units | English | Metric |
\(\large{ \Delta P }\) = pressure loss | \(\large{\frac{lbf}{in^2}}\) | \(\large{Pa}\) |
\(\large{ \bar {v} }\) = average velocity | \(\large{\frac{ft}{sec}}\) | \(\large{\frac{m}{s}}\) |
\(\large{ \rho }\) (Greek symbol rho) = density | \(\large{\frac{lbm}{ft^3}}\) | \(\large{\frac{kg}{m^3}}\) |
\(\large{ f_f }\) = Fanning friction factor | \(\large{ dimensionless }\) | |
\(\large{ f }\) = friction factor | \(\large{ dimensionless }\) | |
\(\large{ g }\) = gravirational acceleration | \(\large{\frac{ft}{sec^2}}\) | \(\large{\frac{m}{s^2}}\) |
\(\large{ d }\) = inside diameter of pipe | \(\large{ in }\) | \(\large{ mm }\) |
\(\large{ l }\) = lenght of pipe | \(\large{ ft }\) | \(\large{ m }\) |
\(\large{ v }\) = velocity of fluid | \(\large{\frac{ft}{sec}}\) | \(\large{\frac{m}{s}}\) |
Tags: Equations for Pressure