# PressureLosses

## Copyright © EDF 2002 - 2025

## ThermoSysPro Version 4.2

Pressure Losses  


Pressure loss, or pressure drop, is the difference in fluid pressure between two points of a pipe. Pressure loss is due to frictional forces. Its main determinants are the fluid velocity and viscosity. The Bernoulli equation is used to calculate the friction pressure loss coefficient for single- and  
two-phase flow (evaporation and condensation).  

For a better understanding of the underlying physics, see Chap. 13 of {cite:p}`el19`.