What device is responsible for automatically controlling the speed of a steam turbine?

The governor valve is designed specifically to automatically control the speed of a steam turbine. It does this by adjusting the flow of steam into the turbine based on the actual speed of the turbine compared to the desired set point. When the turbine speed decreases, the governor valve opens to allow more steam to flow into the turbine, increasing its speed. Conversely, if the speed exceeds a certain limit, the governor closes the valve to reduce steam flow, thereby preventing overspeed conditions and maintaining safe operational levels.

This automatic regulation is crucial for the stability and efficiency of turbine operation, especially under varying load conditions. It ensures that the turbine runs smoothly and efficiently, contributing to overall system reliability.

In contrast, a turbine brake is used to slow down or stop the turbine, a throttle valve is responsible for controlling the power output by varying steam flow, and a pressure regulator maintains a specific pressure in steam lines but does not directly manage turbine speed.