Question 462Steam Plants - Assistant Engineer

The correct answer is B) constant pump discharge pressure governor. The main boiler feed pump discharge is controlled by the admission of steam to the auxiliary turbine. The admission of steam is normally regulated by a constant pump discharge pressure governor. This governor maintains a constant discharge pressure from the boiler feed pump by adjusting the amount of steam admitted to the auxiliary turbine, which in turn controls the pump's speed and output. The other options are incorrect because: A) a flyweight controlled regulating valve is not specifically used to control the boiler feed pump discharge; C) a multi-nozzle arrangement is not the primary means of regulating the steam admission; and D) a constant speed limiting governor would maintain a fixed pump speed rather than adjusting it to maintain constant discharge pressure.