______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
______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
相关考题：
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
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
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
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
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
单选题Vessels having main engines arranged for air starting are to be provided with at least （）Aone automatic drain serving both containersBtwo air starting containers of approximately equal sizeCone control air container and one starting air containerDone additional means of starting the main engine
单选题The opening or closing of the cylinder starting valve is controlled by （）.Athe starting air distributorBthe cut-off valve on the air mainCthe main starting valveDthe air bottle control valve
单选题The main purpose of starting the diesel engine on air briefly is（）Ato inspect if the cylinder has the water leakageBto expel out the residual water/gas/oil from the cylinderCto check if fuel supply is normalDA and B
单选题（） device is provided to prevent starting air from being admitted to the cylinder before the reversing is completed.AAn automaticBA transmissionCA self-regulatingDAn interlocking
单选题The starting air system usually has （） to prevent starting if anything is not in order.Astop valvesBinterlocksCnon-return valvesDair vents
单选题The starting air system usually has （） to prevent starting if anything is not in order.Adrain cocksBvent valvesCcounteractsDinterlocks
单选题Condensate must be drained periodically from the air compressor receivers to prevent （）.Asecond stage cylinder lockupBoil sump contaminationCfaulty operation of pneumatic valvesDcorrosion of air receiver baffles
单选题Which of the following conditions could contribute to the cracking of a diesel engine cylinder head?（）ALeaking seal ringBInsufficient heat transfer from the exhaust valvesCBlock cooling water passages to the headDExcessive scavenging air provided to the engine
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（）Aintake strokeBcompression strokeCpower strokeDexhaust stroke
单选题Diesel engine cylinder head test cocks are used to（）Acheck cylinder lubrication prior to starting engineBconnect exhaust gas analyzers to determine engine efficiencyCpressure test cylinder heads to check for leaksDremove moisture accumulations from cylinder prior to starting
单选题Which of the following methods is used to prevent throttling of compressed air through the diesel engine air starting valves?（）AHolding the valve open for a long periodBIncreasing the starting air pressure usedCOpening the stating air valve quicklyDReducing the starting air valve size
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 （）.ABDCBTDCCBBDCDATDC
单选题Compressed air is supplied by air compression to （）.Athe air receiversBthe starting valvesCthe cylinder coversDthe distributors
单选题In the event of the cylinder starting valve leakage （） would pass into the air pipes and ignite the oil deposited.Acooling waterBvapor from the boilerCstarting airDhot gases
单选题During （）, the starting air valves should be closed to prevent the engine from turning.AoverhaulBrunningCblowing downDAll of the above are correct
单选题A safety outlet is provided on the CO2 discharge piping to prevent（）.Aover pressurization of the space being floodedBrupture of cylinder due to temperature increaseCover pressurization of the CO2 discharge pipingDflooding of a space where personnel are present
单选题The principal difference between loop scavenging and crossflow scavenging, as used in single acting diesel engines, is the （）Adirection of air flow within the cylinderBsequence of port openingCmethod of opening exhaust portsDvolume of air admitted to the cylinder
单选题When starting air is admitted, a diesel engine turns over very slowly without firingThe cause may be （）Aan obstruction in an cylinderBwater accumulation in some engine cylindersClow starting air pressureDlow scavenge air pressure
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.AjustBnearlyCmerelyDalready
单选题In an operating diesel engine, which of the following condition is an indication of a leaking air starting valve?（）Anoise coming from that air starting valveBcontinuous operation of the starting air compressorCzero air pressure in the air starting systemDoverheated starting air pipe to the cylinder head
单选题The air distributor is conventionally driven by（） and distributes into each cylinder by（） certain sequence.Acamshaft；fresh airBcamshaft；starting airCelectronic motor which is controlled by a computer；fresh airDelectronic motor which is controlled by a computer；starting air