What are the four trip conditions that can occur on a steam turbine?

The identification of the four trip conditions specifically relates to the operational safety and reliability of steam turbines. Overspeed indicates that the turbine is rotating faster than its designed maximum speed, which can cause mechanical failure. High vibration suggests problems such as imbalance or misalignment, which can lead to severe damage if not addressed. Generator trips may occur due to fluctuations in electrical output or other conditions that require the turbine to be shut down for safety reasons. Water seal loss refers to the loss of a necessary barrier function that helps to prevent leakage and maintain proper operation, which can impact the turbine’s efficiency and safety.

The other options do not accurately reflect the critical conditions that typically lead to the tripping of a steam turbine. While elements like high back pressure and low lube-oil pressure are important in overall turbine health, they do not represent the primary trip conditions. Similarly, high and low pressures or temperatures may influence operational performance but are not categorized as trip conditions in the context of steam turbine safety as clearly as the conditions mentioned in the correct option.