Question 313Steam Plants - Assistant Engineer
70% to passWhen the flame scanner senses flame failure during boiler operation, which of the listed events will occur FIRST?
AThe automatic purge cycle commences.
BThe 'trial for ignition' period commences.
CThe fuel oil solenoid valve is de-energized.
DThe fuel oil service pump is stopped.
AI Explanation
The correct answer is C) The fuel oil solenoid valve is de-energized. When the flame scanner senses a flame failure during boiler operation, the first action that occurs is the fuel oil solenoid valve being de-energized. This immediately stops the flow of fuel oil to the burner, cutting off the fuel supply to prevent a potentially dangerous situation. The other listed events, such as the automatic purge cycle, trial for ignition period, and fuel oil service pump stoppage, occur after the solenoid valve is de-energized as part of the boiler's safety shutdown sequence.
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