This lesson describes the basic operation of the valves that control the speed and operation of a typical steam turbine. • Identify the purpose of the main steam stop valves • Identify how main steam stop valves affect a unit’s operation in BES emergency operations • Identify how turbine speed control affects a unit’s ability to support normal, contingency, and emergency BES operations • Identify the purpose of the turbine governor and control valves • Identify the difference between reheat and intercept valves • Identify how turbine valves are manipulated by Automatic Generation Control (AGC) systems using Area Control Error (ACE) data • Recognize what happens during a turbine trip • Recall the basic operation of a flyweight governor control system • Identify the difference between full arc admission and partial arc admission • Identify common steam turbine ramp rates • Identify steam turbine viability as an option in normal, contingency and emergency operations