One of the biggest problems when analysing pipe network behaviour is the difficulty in accounting for the actual components features, as some conditions change in relation to the designed one. This problem occurs, for example, when some power machines, like turbines or pumps, are connected to the pipes. In fact, for these devices, one how rate value corresponds to each pressure value and vice versa. For this reason, the pipe network operating points depend on both pipe geometry and the physical behaviour of the other components. Furthermore, when hot and multi-component fluids are considered, thermal loss and composition calculations are required to correctly evaluate pipe behaviour. In the following, a simulation code developed by the author (Power Pipe) has been applied to a real geothermal power plant in which the wells can be considered as expanders, and the power unit is a steam turbine plant. Design and off design analyses have been performed by accounting for the exergetic loss of the system components.