Question 529Steam Plants - Assistant Engineer70% to pass
With vacuum up and the main propulsion turbine standing by while awaiting engine orders, it is necessary to roll the unit alternately ahead and astern every five minutes to _______________.
AI Explanation
The correct answer is B) reduce the possibility of warping the turbine rotors.
When a steam turbine has been shut down, the rotors can become warped if they are not rotated periodically. Rotating the turbine unit ahead and astern every 5 minutes helps to prevent this warping by evenly distributing the heat and stresses on the rotors. This regular alternating rotation keeps the rotors from becoming deformed or out of alignment, which could lead to damage when the turbine is restarted.
The other answer choices are incorrect because they do not address the primary purpose of the periodic rotation, which is to maintain the integrity of the turbine rotors.
Related Questions
#527 After starting the main lube oil pump in a gravity-type lube oil system, you should verify that the gravity tanks are full by _______________.#528 When a turbine rotor is not rotating during maneuvering, the heat tends to be concentrated at the _______________.#530 Which of the journal bearings listed most easily accommodates the minor turbine shaft misalignment? #531 On a main propulsion turbine bearing, the readings obtained with a bridge gage represent the _______________.#532 The adjustable spherically seated self-aligning bearing housings used in main turbines are provided with oil deflector rings. The function of these rings is to _______________.