Definition: The word 'Presse' means a press or pressurized water system, often used in hydroelectric power plants to prevent steam pressure from exceeding safety limits. Definition: A system designed to prevent sudden or large-scale damage to equipment by providing an immediate venting and de-pressurization of the steam stream. This is typically done by placing a pressure regulator inside the turbine itself, preventing the steam from being allowed to reach the turbine casing during maintenance, as well as during starting up in case of any issues with the plant's components. This concept was originally used in the 19th century for steam turbines, but later expanded to include all types of power plants.