Question 314Steam Plants - 1st Asst/Chief

The correct answer is B) E. The follow-up mechanism in the turbo-generator governing system, which prevents the nozzle valves from cycling between the fully open and fully closed positions with each variation in turbine speed, is the speed error feedback device (labeled E in the illustration SE-0009). This feedback device senses the generator speed and provides a corresponding electrical signal to the speed governor (labeled D), which in turn adjusts the nozzle valve position to maintain a stable, steady speed. The other options (A, C, and D) do not directly perform this follow-up function to prevent rapid valve cycling.