Question 5Steam Plants - Assistant Engineer
70% to passWhile trying to light off a burner on a semi-automated boiler, you note that the fuel oil solenoid valve at the burner will not stay open. Which of the following conditions could cause this problem?
AThe fuel oil pressure at that burner is too high.
BThe solenoid coil is energized causing the valve to remain closed.
CThe forced draft air supply has failed.
DThe flame scanner is adjusted for excessive time delay in the ignition trial circuit.
AI Explanation
The correct answer is C) The forced draft air supply has failed. If the forced draft air supply has failed, the lack of air flow to the burner would prevent the fuel oil solenoid valve from staying open. Without the proper air/fuel ratio, the burner would be unable to sustain combustion, causing the solenoid valve to close. The other options are incorrect because: A) High fuel oil pressure would not prevent the solenoid valve from opening. B) The solenoid coil being energized would keep the valve open, not closed. D) Ignition trial circuit timing issues would not affect the solenoid valve operation.
Related Questions
Q530:Which of the journal bearings listed most easily accommodates the minor turbine ... Q501:After restoring the normal water level in a boiler following a high water casual... Q589:In securing the main turbines, steam to the second stage air ejectors should be ... Q499:Which action should be taken if the water level in the boiler gage glass drops o... Q188:Which of the valves listed should be closed before lighting off a boiler? ...
Ready to test your knowledge?
Take a Steam Plants - Assistant Engineer Practice ExamOfficial Resources