单项选择题
Which of the following statements concerning the lubrication of diesel propulsion engines used in vessels over 300 gross tons is most accurate?()
A.Lubrication systems using engine driven lube oil pumps do not require any additional independent arrangement when such arrangements have been proven reliable
B.The use of engine driven pre-lube pumps is permitted on vessels with propulsion systems developing less than 500 shaft horsepower
C.When forced lubrication is used for propulsion engines, one independently driven stand-by pumps is to be provided in addition to the necessary pumps for normal operation
D.Lubrication systems where two oil coolers are fitted require a minimum of two temperature control devices which may be actuated by similar sensors
相关考题
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单项选择题
If the coolant temperature of a closed cooling water system for a diesel engine gradually increases, the trouble usually is ()
A.a broken shaft on the freshwater pump
B.an excessive accumulation of scale exchanger
C.an incorrect thermostatic element operating range
D.lube oil in the cooling water -
单项选择题
The amount of fuel delivered by a helical plunger fuel injection pump is controlled by ()
A.varying the pump discharge pressure
B.varying the pump return pressure
C.rotation of the pump plunger
D.rotation of the pump barrel -
单项选择题
On a diesel engine equipped with a hydraulic speed control governor, hunting in many cases can be corrected by adjusting the ()
A.accumulator spring compressor
B.balance piston
C.compensating needle valve
D.proportional piston
