Fuel injectors used in heavy fuel oil systems are usually provided with cooling to reduce（）.

[单选题]Injectors for use with heavy fuel oil must be cooled by either water or light oil to_____.A．prevent heat corrosion to internal componentsB．increase fuel delivery rate and economyC．prevent pre-ignitionD．avoid carbonization of the nozzle tips

[单选题]When centrifuging heavy fuel oil, an important factor to consider is the （）(1) flow rate(2) viscosity of the fuel oilA . (1) only is correctB . (2) only is correctC . both (1) and (2) are correctD . neither (1) or (2) are correct

[单选题]In a commonly used fuel oil system, the oil is stored in tanks in the double bottom from which it is pumped to （） and heated.A . a service tankB . a settling tankC . an expansion tankD . a double bottom tank

[单选题]Fuel oil transfer systems used onboard diesel propelled vessels are required to have （）.A . two fuel oil transfer pumps provided where one is to be independent of the main engineB . two fuel oil transfer pumps, with a combined capacity exceeding the

[单选题]Springs in fuel injectors will become not strong enough to work because______.A．the injector opens at a lower pressure than designedB．the needle valve and seat wear outC．the nozzle holes wear outD．long time in use

[单选题]In a typical fuel oil system, the oil is stored in tanks in the double bottom from which it is pumped to （） and heated.A . a service tankB . a collecting tankC . a sumpD . a settling tank

[单选题]The quality of the fuel oil and lube oil （）, Im afraid.A . has much to do with the operation of the engine and its lifeB . have much to do with the operation of the engine and its lifeC . has much doing with the operation of the engine and its lifeD

[单选题]If there is water in fuel oil, the revolution of the engine will （）.A . decreaseB . increaseC . be dismantledD . be reassembled

[单选题]When the fuel oil is burning in the combustion chamber, it _____.A．gives up large amount of heatB．gives off large amount of heatC．gives up large amount of steamD．gives off large amount of steam

[单选题]The fuel oil system for a diesel engine can be considered in two parts--the fuel supply and the （） systems.A . fuel treatmentB . fuel combustionC . fuel injectionD . fuel separating