单选题Air chambers are usually fitted to reciprocating pumps in order to （）.Aincrease discharge pressureBincrease suction vacuumCdevelop pulsation flowDkeep a steady rate of flow
单选题
Air chambers are usually fitted to reciprocating pumps in order to （）.
A
increase discharge pressure
B
increase suction vacuum
C
develop pulsation flow
D
keep a steady rate of flow
参考解析
解析：
暂无解析
相关考题：
_______is usually driven by the engine camshaft and supplies pilot air to the cylinder air start valve.A.An air receiverB.An operating valveC.An automatic valveD.An air distributor
If a reciprocating air compressor has a knock occurring in frequency with its operating RPM, the cause is probably _____.A.misalignment or worn main bearingsB.insufficient cylinder lubricationC.defective or poorly fitted valvesD.All of the above
Centrifugal pumps have what advantage（s）over reciprocating pumps ________．A.They are less expensiveB.They are smaller for equivalent pumping abilityC.They pump more cargo in less timeD.All of the above
What is the most probable cause of reduced capacity in a reciprocating air compressor ________．A.Carbon on cylinder headsB.Faulty unloaderC.Leaking air valvesD.Plugged air cooler
单选题Excessive lube oil consumption by a reciprocating air compressor can be caused by （）.Ausing a slightly dirty air filterBusing oil having an excessive viscosityCintercooler or after-cooler leaksDcarrying the oil level higher than normal
单选题Mechanical lubricators for diesel engine cylinders are usually small reciprocating pumps which are （）.Aoperated manually once an hourBoperated until the engine has startedCplaced into operation only at maximum loadDadjustable to meet lubrication requirements
单选题To obtain maximum efficiency, two stage air compressors are usually （）.Ahorizontally mountedBnever fitted with intake filtersCfitted with intercoolersDoperated in an unloaded condition at all times
单选题In an air conditioning system, low head pressure associated with a reciprocating compressor can be the result of （）Abroken valve springsBtight drive beltsChigh line voltageDair in the system
单选题A gypsy or gypsyhead is a（）.Apunt used for painting over the sideBsmall, reciprocating steam engineCspool-shaped drum fitted on a winchDswinging derrick
单选题Which of the following statements represents the advantage of rotary pumps as compared to reciprocating pumps?（）AThe high discharge pressure of the rotary pumps permits a larger volume of fluid per unit time than the reciprocating pumpBRotary pumps are capable of pumping more fluid than reciprocating pumps of the same weightCRotary pumps occupy only one-half the space of reciprocating pumpsDRotary pumps eliminate discharge slippage of the pumped liquid, while this does not hold true for a reciprocating pump
单选题Failure of fuel injection is usually due to trouble in the （）.Aexhaust valvesBmechanical lubricatorsCcooling water pumpsDfuel injection pumps
单选题The pressurized air is usually cooled to increase the charge air （）.AviscosityBdensityCvelocityDelectricity
单选题A reciprocating pump belongs to （） according to its working principle.Ainjector pumpsBpositive displacement pumpsCcentrifugal pumpDcentripetal pumps
单选题Centrifugal pumps have what advantage(s) over reciprocating pumps?（）.AThey are less expensiveBThey are smaller for equivalent pumping abilityCThey pump more cargo in less timeDAll of the above
单选题Which of the listed operating conditions would have the greatest effect on the volumetric efficiency of an operating reciprocating air compressor?（）AThe density of the air entering the compressorBThe temperature of the air entering the compressorCThe designed rotating speed of the compressorDA leaking head gasket
单选题（） is usually driven by the engine camshaft and supplies pilot air to the cylinder air start valve.AAn air receiverBAn operating valveCAn automatic valveDAn air distributor
单选题The air compressor pumps air to the （）.Aexpansion tankBcombustion chamberCair receiverDevaporator
单选题The air compressor pumps air to the （）.Aair cylinderBcombustion chamberCsteam drumDexpansion tank
单选题A reciprocating air compressor is running roughly and vibrating excessively, indicating that the （）.Acompressor is overloadedBmotor is overloadedCfoundation bolts are looseDbelts are too tight
单选题The air reservoirs must have （） fitted to prevent rupture in the event of fire.Ahigh pressure alarmBfire alarmCextinguishersDfusible plugs
单选题If a reciprocating air compressor has a knock occurring in frequency with its operating RPM, the cause is probably （）.Amisalignment or worn main bearingsBinsufficient cylinder lubricationCdefective or poorly fitted valvesDall of the above
单选题（） or air venting arrangement is fitted to the fuel supply passage.AAn air pumpBA compressorCA fuel pumpDA priming
单选题Excessively low air pressure occurring in the intercooler of a reciprocating air compressor is caused by（）.Aleaky discharge valves on the LP cylinderBleaky discharge valves on the HP cylinderCinsufficient intercooler coolingDlow ambient air pressure
单选题By far the greatest item of maintenance of the reciprocating air compressors concerns （）.Athe lubricationBthe coolingCthe moisture separationDthe valves
单选题The air required for combustion is taken from the engine room through a filter fitted on the turbochargerThis reduces the risk for too and contamination of the combustion air（）Ahigh temperaturesBlow temperaturesCwetDdirty