What is the function of the vacuum breaker in a steam turbine?

The function of the vacuum breaker in a steam turbine is primarily to prevent the formation of a vacuum that can cause operational issues. Specifically, the vacuum breaker helps maintain the appropriate pressure levels within the system, which is essential for the efficient operation of the turbine. If a vacuum develops, it can lead to cavitation and other related problems that affect performance and may lead to damage.

By allowing air to enter the system when the pressure falls below atmospheric levels, the vacuum breaker helps ensure there is sufficient pressure for effective water drainage and aids in protecting against damage. This function is crucial in maintaining the turbine's operational efficiency and overall reliability.

While achieving a faster coast down cycle may be a consideration within turbine operations, it's not the primary role of the vacuum breaker. Instead, its main function pertains to pressure management and preventing the complications associated with vacuum formation.