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______device is provided to prevent starting air from being admitted to the cylinder before the reversing is completed.
A.An automatic
B.A transmission
C.A self-regulating
D.An interlocking
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更多 “ ______device is provided to prevent starting air from being admitted to the cylinder before the reversing is completed.A.An automaticB.A transmissionC.A self-regulatingD.An interlocking ” 相关考题
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US and allied officials have said they have seen no credible evidence of civilian casualties(伤亡)from the air campaign,and they say that precision weapons are used in the strikes in an effort to()being hurt.A. prevent civilians onB.prevent civilians fromC. Prevent civilians toD.Prevent civilians in
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第二组Under normal operation, some lubrication oil mist may be discharged from the air compressor to the air start system. This oil may be from excess compressor cylinder lubrication, from faulty oil scraper rings, or may even be suspended oil vapor contaminating the engine room atmosphere and drawn in at the compressor suction. Oil discharge is kept to a minimum by draining the after cooler, air receiver and starting system. If small quantities of lubrication oil do get passed into the starting air system, they will deposit as thin moist film over internal pipe surfaces but are not readily combustible. If a cylinder non-return valve leak while the engine is in operation, some hot gas, possibly with unburned fuel and cylinder lubrication oil, may be blown through the valve to the adjacent air manifold. With further heating from the leaky valve, this, together with the already deposited oil film, will carbonize and form. incandescent carbon. If starting air is applied to the system while still hot, the high pressure air coming into contact with the burning carbon may cause an explosion. Such an explosion will cause a flame to pass back through the air start pipe system, evaporating the deposited oil film and igniting it in the presence of air. Very high velocities and shockwaves are generated which may rupture pipes and fittings.Alternatively, if excessive oil has entered the air start system, a mixture of air and oil droplets may be discharged through the open cylinder non-return valve during starting. This spray may ignite due to high temperatures in the cylinder, causing a flame through the still open valve to the air manifold.To prevent an explosion, air start valves must be correctly maintained and lubricated to ensure correct timing and free movement with positive closing. Oil in the system must be kept to a minimum, pipe lines must be drained and cleaned internally when necessary and oil discharge from air compressors must be kept to a minimum by good maintenance.The passage is mainly aboutA.crankcase explosionB.scavenge box fireC.starting air pipeD.the danger of explosion in the starting air system
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Vessels having main engines arranged for air starting are to be provided with at least__.A.one automatic drain serving both containersB.two air starting containers of approximately equal sizeC.one control air container and one starting air containerD.one additional means of starting the main engine
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In an operating diesel engine, which of the following conditions is an indication of a leaking air starting valve?A.Noise coming from that air starting valveB.Continuous operation of the starting air compressorC.Zero air pressure in the air starting systemD.Overheated starting air pipe to the cylinder head
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In the event of the cylinder starting valve leakage ______would pass into the air pipes and ignite the oil deposited.A.cooling waterB.vapor from the boilerC.starting airD.hot gases
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单选题Vessels having main engines arranged for air starting are to be provided with at least ()A
one automatic drain serving both containersB
two air starting containers of approximately equal sizeC
one control air container and one starting air containerD
one additional means of starting the main engine
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单选题The opening or closing of the cylinder starting valve is controlled by ().A
the starting air distributorB
the cut-off valve on the air mainC
the main starting valveD
the air bottle control valve
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单选题The main purpose of starting the diesel engine on air briefly is()A
to inspect if the cylinder has the water leakageB
to expel out the residual water/gas/oil from the cylinderC
to check if fuel supply is normalD
A and B
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单选题() device is provided to prevent starting air from being admitted to the cylinder before the reversing is completed.A
An automaticB
A transmissionC
A self-regulatingD
An interlocking
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单选题The starting air system usually has () to prevent starting if anything is not in order.A
stop valvesB
interlocksC
non-return valvesD
air vents
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单选题The starting air system usually has () to prevent starting if anything is not in order.A
drain cocksB
vent valvesC
counteractsD
interlocks
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单选题Condensate must be drained periodically from the air compressor receivers to prevent ().A
second stage cylinder lockupB
oil sump contaminationC
faulty operation of pneumatic valvesD
corrosion of air receiver baffles
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单选题Which of the following conditions could contribute to the cracking of a diesel engine cylinder head?()A
Leaking seal ringB
Insufficient heat transfer from the exhaust valvesC
Block cooling water passages to the headD
Excessive scavenging air provided to the engine
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单选题When an air started, four-stroke/cycle diesel engine is being cranked, the starting air is admitted to each cylinder during what would normally be the()A
intake strokeB
compression strokeC
power strokeD
exhaust stroke
考题
单选题Diesel engine cylinder head test cocks are used to()A
check cylinder lubrication prior to starting engineB
connect exhaust gas analyzers to determine engine efficiencyC
pressure test cylinder heads to check for leaksD
remove moisture accumulations from cylinder prior to starting
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单选题Which of the following methods is used to prevent throttling of compressed air through the diesel engine air starting valves?()A
Holding the valve open for a long periodB
Increasing the starting air pressure usedC
Opening the stating air valve quicklyD
Reducing the starting air valve size
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单选题The compressed air is admitted to each cylinder through a cam operated by starting air valve when the piston has just passed its ().A
BDCB
TDCC
BBDCD
ATDC
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单选题Compressed air is supplied by air compression to ().A
the air receiversB
the starting valvesC
the cylinder coversD
the distributors
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单选题In the event of the cylinder starting valve leakage () would pass into the air pipes and ignite the oil deposited.A
cooling waterB
vapor from the boilerC
starting airD
hot gases
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单选题During (), the starting air valves should be closed to prevent the engine from turning.A
overhaulB
runningC
blowing downD
All of the above are correct
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单选题A safety outlet is provided on the CO2 discharge piping to prevent().A
over pressurization of the space being floodedB
rupture of cylinder due to temperature increaseC
over pressurization of the CO2 discharge pipingD
flooding of a space where personnel are present
考题
单选题The principal difference between loop scavenging and crossflow scavenging, as used in single acting diesel engines, is the ()A
direction of air flow within the cylinderB
sequence of port openingC
method of opening exhaust portsD
volume of air admitted to the cylinder
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单选题When starting air is admitted, a diesel engine turns over very slowly without firingThe cause may be ()A
an obstruction in an cylinderB
water accumulation in some engine cylindersC
low starting air pressureD
low scavenge air pressure
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单选题When the starting air valve closes on one cylinder, another starting air valve has () opened on another cylinder whose piston has just commenced its downward stroke.A
justB
nearlyC
merelyD
already
考题
单选题In an operating diesel engine, which of the following condition is an indication of a leaking air starting valve?()A
noise coming from that air starting valveB
continuous operation of the starting air compressorC
zero air pressure in the air starting systemD
overheated starting air pipe to the cylinder head
考题
单选题The air distributor is conventionally driven by() and distributes into each cylinder by() certain sequence.A
camshaft;fresh airB
camshaft;starting airC
electronic motor which is controlled by a computer;fresh airD
electronic motor which is controlled by a computer;starting air
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