Condensing steam turbine with level sensing device and methods for regulating the level

A condensing steam turbine comprises a condensate reservoir (1) for storing the condensed working fluid (10) of the condensing steam turbine and a level detection means for detecting the filling level in the condensate reservoir. The level detection means comprises a first pressure detecting means (2) for detecting a first pressure (P1) of the condensed working fluid (10) at a first height in the condensate reservoir, a second pressure detecting means (3) for detecting a second pressure (P0) above a second level in the condensate reservoir and an evaluation device for forming the pressure differential (.DELTA.P) between first and second respective pressure and for outputting an output signal of this pressure difference.