Question 110Motor Plants - 1st Asst/Chief

70% to pass

When changing over from residual to distillate fuel on a slow-speed diesel propelled vessel, you should limit the rate of temperature change of the fuel in order to prevent what operational difficulty?

ASeizing and scuffing of fuel pump plungers and injector needle valves due to thermal effects on close clearance components.
BDezincafication of the fuel in the mixing tank.
CSurging/hunting of the governor due to rack sticking.
DCarbonization in the fuel heater.
AI Explanation

The correct answer is A) Seizing and scuffing of fuel pump plungers and injector needle valves due to thermal effects on close clearance components. When changing over from residual to distillate fuel, the fuel temperature needs to be changed gradually to prevent thermal shock to the engine's fuel system components. Sudden changes in fuel temperature can cause the metal fuel pump plungers and injector needle valves to seize or become scuffed due to the differing thermal expansion rates between the components. This can lead to operational difficulties and potential engine damage. The other answer choices do not directly relate to the effects of rapid fuel temperature changes during the fuel changeover process.

Related Questions
Q@q.QuestionNumber:An exhaust gas bypass is installed on a waste heat boiler in order to___________... Q@q.QuestionNumber:Telescopic pipes which are attached to water cooled pistons of large, slow-speed... Q@q.QuestionNumber:While operating the fuel oil centrifuge shown in the illustration, the bowl fail... Q@q.QuestionNumber:When one cylinder has a lower compression pressure and higher exhaust gas temper... Q@q.QuestionNumber:Regarding the fuel injector shown in the illustration, the purpose of piece #38 ...

Ready to test your knowledge?

Take a Motor Plants - 1st Asst/Chief Practice Exam
Official Resources
46 CFR Machinery & Electrical 46 CFR Engineering USCG National Maritime Center
← Previous All Questions Next →

Want to practice with timed exams?

Download Coast Guard Exams for the full exam experience.

Get the App