网友您好， 请在下方输入框内输入要搜索的题目：
题目内容
（请给出正确答案）
单选题
In the common rail system, excessive pressure in the header may be caused by （）
A
improper adjustment of the bypass valve
B
a dribble in the fuel injection nozzle
C
insufficient leak-off through injection nozzle packing
D
a malfunctioning injection nozzle
参考答案
参考解析
解析：
暂无解析
更多 “单选题In the common rail system, excessive pressure in the header may be caused by （）A improper adjustment of the bypass valveB a dribble in the fuel injection nozzleC insufficient leak-off through injection nozzle packingD a malfunctioning injection nozzle” 相关考题
考题
Low compressor head pressure in a refrigeration system can be caused by ___.A.insufficient condenser cooling waterB.excessive condenser cooling waterC.air in the refrigeration systemD.excessive refrigerant in the system
考题
Air trapped in the hydraulic fluid of a steering system may be indicated byA.the steering pumps overspeedingB.a jammed open relief valveC.a constantly occurring improper rudder responseD.excessive ram pressure
考题
Sweating of the refrigeration system compressor crankcase is caused by_______ .A.too much superheatB.insufficient superheatC.suction pressure too lowD.excessive refrigerant returning to the compressor
考题
Which of the following problems could cause the high pressure cutout switch to shut down the compressor in a refrigeration system?A.A shortage of liquid refrigerant.B.Excessive frost on the evaporator.C.Excessive condenser cooling water.D.Insufficient condenser cooling water flow.
考题
If a diesel engine turned over freely but failed to start, the cause could be ________.A.water in the fuelB.cold lube oilC.excessive starting air pressureD.excessive fuel pressure
考题
If a centrifugal pump is driven by a constant speed electric motor and produces a discharge pressure less than designed, the cause is probably ______.A.excessive pump speedB.excessive suction headC.worn wearing ringsD.gross pump misalignment
考题
An increase in the heat load to a refrigeration system will cause ______.A.the suction pressure to decreaseB.the suction temperature to increaseC.increased ice formation on the evaporator coilD.excessive short cycling of the compressor
考题
Restrictions occurring in the small orifices(孔) of pneumatic control system components can be caused by ______.A.moisture in the compressed air supplyB.excessive dryness in the compressed air supplyC.pressure surging in the compressed air receiverD.insufficient lubrication of the system components
考题
（） is a system of unitized multimodal land transportation of transport by road and rail.A、Land bridgeB、Rail/roadC、PiggybackD、Sea/air
考题
Which of the following is the MOST common problem that occurs in server rooms？（）A、 Excessive coolingB、 Dust buildupC、 Poor ground wiresD、 Wet floors
考题
单选题In （） pump a closed discharge valve will not cause excessive pressure to build up.A
gearB
vaneC
screwD
centrifugal
考题
单选题How does an inert gas system on a tanker function to prevent explosions in cargo tanks? （）A
De-energizes the charged mist effectB
Maintains a positive pressure on the vent header to cool the flammable vaporsC
Inert gas filters out the flammable vapors from the cargo tank spacesD
Inert gas dilutes the flammable vapor and air concentrations to keep them below the lower explosive limit
考题
单选题An increase in diesel engine crankcase pressure generally indicates excessive（）A
compression pressureB
lube oil header pressureC
scavenge air pressureD
piston ring blow-by
考题
单选题Most hydraulic steering gears are fitted with relief valves which（）A
function when the rudder is amidshipsB
relieve excess whip pressure from the hydraulic oil systemC
protect the piping assembly from external rudder shockD
relieve excessive telemotor pressure
考题
单选题Excessive diesel engine back pressure may be an indication of （）A
carbon buildup in the exhaust manifoldB
overcooling of the exhaust manifoldC
eroded muffler baffle platesD
high injection pressure
考题
单选题Which of the following will take place if the clearance of the main bearings are excessive?（）A
bearing knocksB
dropping of pressure of LOC
noisesD
all the above
考题
单选题Which of the following may take place if the clearance of the main bearings are excessive?（）A
bearing knocksB
dropping of pressure of LOC
noisesD
all the above
考题
单选题In conventional systems, the injection pressure（）, while it’s（）in common rail diesel engines.A
fluctuates with the engine speed to some extent, independent of the engine speedB
keeps constant at all engine speed, dependent on the engine speed to some extentC
keeps constant at all engine speed, independent of the engine speedD
is decided by the engine speed, constant at all engine speed
考题
单选题Excessive clearances in the main or crank-pin bearings will sometimes be indicated by （） before any bearing knock is heard.A
loss of flow in the fuel systemB
loss of pressure in the air systemC
loss of flow in the lubricating systemD
loss of pressure in the lubricating system
考题
单选题An excessive charge of refrigerant in an air-cooled refrigeration system can cause （）.A
oil foaming in the compressorB
higher than normal suction and discharge pressures with a higher box temperatureC
higher than normal discharge pressure with a normal box temperatureD
the compressor to run continuously
考题
单选题An un-loader is installed on an air compressor to （）.A
bypass the high pressure stage to the low pressure stage on 100% of the air compressors in serviceB
prevent excessive inter-stage pressure buildupC
control compressor discharge pressureD
remove all but the frictional load during starting
考题
单选题A swing check valve is used in a pipeline to （）.A
maintain a preset pressure on the lineB
closely regulate the amount of flowC
relieve excessive pressure on the lineD
allow flow in one direction only
考题
单选题A crew member reports that the high-pressure alarm light of a low-pressure CO2 fixed fire extinguishing system is illuminated. The most probable cause of this condition would be that（）.A
an air leak has developed in the tankB
the tank cooling system has malfunctionedC
the pilot cylinder discharge valve is leakingD
an excessive amount of insulation has been installed on the tank and piping
考题
单选题（）uses one or two high pressure pumps for all the cylinders with one more standby, while（）have a separate high-pressure pump for each cylinder.A
A common rail engine；conventional enginesB
A conventional engine；common rail enginesC
A marine diesel engine；most other enginesD
A two-stroke engine；four-stroke engines
考题
单选题In common rail engines, the fuel is（） before is injected into the cylinders.A
stored in a common fuel lineB
pumped by the injection pumpC
at low pressureD
already atomized
考题
单选题A common rail engine has only one or two high pressure pumps in operation at the same（）time, and the injection into each cylinder.A
can’t be controlled very preciselyB
can’t be controlled as flexibly as the separate pump systemC
can be controlled as flexibly as the separate pump systemD
can be controlled more precisely and flexibly
热门标签
最新试卷