What is the function of wearing rings found on some centrifugal pumps ________．A.Absorb erosion of high velocity discharge streamB.Seal pump shaft against entry of airC.Isolate the outlet side from the inlet sideD.Dampen the turbulent discharge flow
What is the function of wearing rings found on some centrifugal pumps ________．
A.Absorb erosion of high velocity discharge stream
B.Seal pump shaft against entry of air
C.Isolate the outlet side from the inlet side
D.Dampen the turbulent discharge flow
相关考题：
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
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 causes cavitation in a centrifugal pump ________．A.Vapor pockets in the flow streamB.Rough impeller surfacesC.Worn wearing ringsD.Heavy fluid in the flow stream
单选题If a centrifugal pump vibrates and is noisy when operating, the cause could be （）.Aworn gland sealing shaftBworn wearing ringsCa bent shaftDreversed pump coupling
单选题What is the function of wearing rings found on some centrifugal pumps? （）AAbsorb erosion of high velocity discharge streamBSeal pump shaft against entry of airCIsolate the outlet side from the inlet sideDDampen the turbulent discharge flow
单选题What is a function of the wearing rings used in most centrifugal pumps?（）AAbsorb erosion of high velocity discharge streamBSeal pump shaft against entry of airCIsolate the discharge side from the suction sideDDampen the turbulent discharge flow
单选题Scuffed cylinder liner wearing surfaces in a diesel engines can result from （）Astarting the engine while hotBknurling the piston skirtCoperating the engine overheatedDscuff resistant piston rings
单选题The pumps employed on board ship can be divided into two main categories ie（） pumps and centrifugal pumps.AgearBnonpositive displacementCpositive displacementDrotary
单选题What is a characteristic of all centrifugal cargo pumps? （）AThey are self-primingBDecreasing the speed of rotation will decrease the discharge pressureCOpening the discharge valve wider will increase the discharge pressureDAll of the above
单选题What function is provided by the crankcase ventilation system on some diesel engines?（）AIncreases the sludge forming tendency of lube oilBPrevents the accumulation of combustible gasesCImproves lube oil coolingDImproves cold weather starting
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Under centrifugal pumps are the volute, diffuser, mixed-flow, axial flow and （） or regenerative types.AreciprocatingBhydraulicCturbineDvane
单选题The capacity of a centrifugal pump can be increased by the installation of a larger diameter impeller Another means of increasing the pump capacity is to （）.Aincrease speedBincrease the size of the cardent assemblyCreduce wearing ring clearancesDchange the pump to a close coupled arrangement
单选题If you were operating a centrifugal water service pump with worn wearing rings, the （）.Apump would be very noisyBpump would vibrate excessivelyCpump would develop insufficient flowDstuffing box would leak excessively
单选题If a centrifugal pump is driven by a constant speed electric motor and produces a discharge pressure less than designed, the cause is probably（）.Aexcessive pump speedBexcessive suction headCworn wearing ringsDgross pump misalignment
单选题To absorb the wear resulting from impeller rotation and abrasives in the liquid, a centrifugal pump is usually fitted with （）.Alantern ringsBbearingsCeasing volutesDwearing rings
单选题Lube oil pumps taking suction from the sump of most small marine engines are usually （）.Aof the diaphragm typeBof the centrifugal typeCof the positive displacement typeDindependently driven by electric motors
单选题If the capacity of a centrifugal pump decreases gradually over a long period of time, you should replace the （）.Apacking glandBmechanical sealsClantern ringsDwearing rings
单选题The piston rings if found worn out （） and supplied by shipchandler.Amust replaceBmust to be equippedChas to be repairedDhave to be renewed
单选题The purpose of the wearing rings used in a centrifugal pump is to （）.Aprevent an internal explosion in the pump when it is overheatedBenable a visual inspection of the pump while it is runningCinsure a proper alignment of the pump coupling to the driverDaccommodate for friction between the impeller and the easing
单选题When installed for bilge pumping or ballast duty, centrifugal pumps require a （） to remove air from the suction pipe.Aair chamberBhead lankCprimerDprime mover
单选题Which of the following pumps belongs to centrifugal pump?（）APiston pumpBScrew pumpCDiffuser pumpDWater-ring pump
单选题To maintain design discharge pressure from a centrifugal pump, the design clearance must be maintained between the （）.Ashaft and impellerBmotor and pump shaftCcasing and impeller wearing ringsDlantern ring and impeller
单选题Which of the materials listed is used as the dynamic seal material on mechanical seals installed on most centrifugal pumps used in water service?（）ACopperBCopper and carbonCCarbonDBronze
单选题Which features of a centrifugal pump reduce the need for renewing worn impellers and pump casings?（）AClose radial clearance between impeller hub and casingBLow rotational speed of impellerCRemovable end plateDReplaceable impeller and casing wearing rings
单选题Centrifugal pumps, however, can be designed with a number of impellers （） to attain a large amount of liquid.Ain seriesBin parallelCassembledDtogether
单选题Which of the listed conditions can lead to cavitation气穴in a centrifugal pump?（）AVapor pockets formed in the suction flow streamBRough easing volute surfacesCWorn wearing ringsDHeavy fluid in the flow stream