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
A centrifugal pump produces the required pressure energy by means of a rotating （） provided with vanes.
A
propeller
B
impeller
C
circumference
D
screw
参考答案
参考解析
解析：
暂无解析
更多 “单选题A centrifugal pump produces the required pressure energy by means of a rotating （） provided with vanes.A propellerB impellerC circumferenceD screw” 相关考题
考题
Throttling in the _____ line of a centrifugal pump involves the risk of the pump cavitation.A.suctionB.exhaustC.pressureD.discharge
考题
Before performing any maintenance on a hydraulic system storing energy in an accumulator, you shouldA.pressurize the system to test for leaksB.bleed off all pressure within the systemC.operate the machine until it reaches normal temperatureD.disconnect the pump pressure control switch
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
All of the following steps are taken in starting a centrifugal pump，EXCEPT to ______．A.Set the relief valveB.Check the lubrication systemC.Vent the pump casingD.Open the pump suction and discharge valves
考题
单选题With respect to centrifugal pump impellers, which of the following descriptions represents the correct centrifugal pump classification? （）A
Single stage or multistageB
High pressure or low pressureC
Open or close coupledD
Horizontal or vertical
考题
单选题While flowing through the volute in a centrifugal pump, part of the （） energy of the liquid is converted to （） energy.A
kinetic；pressureB
kinetic；essentialC
pressure；kineticD
pressure；height
考题
单选题A centrifugal bilge pump requires priming （）.A
primarily to lubricate the shaft sealsB
due to the inability of this type of pump to lift water to cover the suction (eye) of the impellerC
to initially unload the pump by having its head pressure equal to discharge pressureD
in order to overcome the potential energy of water in the discharge line
考题
单选题In general, the oil mist defectors include a base plate with air blast pumpThe function of air blast pump is to （）crankcase.A
supply clean air to the measuring compartment of the units for more accuracyB
generaate the pressure required for the extraction of the oil mist from theC
generate the pressure required for the extraction of the oil mist from the crankcaseD
supply clean air to the measuring track of the units for more accuracy
考题
单选题Which of the following will be the advantage of a centrifugal pump as compared with a reciprocating pump?（） (1) Its discharge is continuous (2) It has no internal valves (3) Upon accidental closing of discharge valve, excessive pressure will not build upA
（1），（2）B
（2），（3）C
（1），（2），（3）D
（2）only
考题
单选题Most pump manufacturers recommended that the discharge piping for centrifugal pumps be （）.A
one size larger than the pump discharge nozzleB
the same size as the pump discharge nozzleC
one size smaller than the pump discharge nozzleD
installed with a short radius elbow at the pump
考题
单选题Increasing the speed of a centrifugal pump will result in an increase in its capacity Another means of increasing the capacity of a centrifugal pump is to increase the （）.A
diameter of the discharge piping, with all other factors remaining the sameB
diameter of the suction piping, with all other factors remaining the sameC
width of the impeller onlyD
diameter of the impeller
考题
单选题All of the following steps are taken in starting a centrifugal pump，EXCEPT to（）.A
set the relief valveB
check the lubrication systemC
vent the pump casingD
open the pump suction and discharge valves
考题
单选题A pump is defined as device that（）A
produces pressureB
imparts energy to a fluid to move it from level ‘A’ to level ‘B’C
creates a vacuum to move a liquid in all installationD
is to develop a pressure differential
考题
单选题A fire pump may be used for other purposes if（）.A
the other services are run off a reducing station with a pressure gageB
one of the required pumps is kept available for use on the fire main system at all timesC
no relief valves are installedD
all of the above conditions are met
考题
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（）.A
excessive pump speedB
excessive suction headC
worn wearing ringsD
gross pump misalignment
考题
单选题The centrifugal pump component responsible for converting the mechanical energy of the liquid being pumped, to that of kinetic energy is the （）.A
electric motorB
voluteC
impellerD
diffusion nozzle
考题
单选题The purpose of the wearing rings used in a centrifugal pump is to （）.A
prevent an internal explosion in the pump when it is overheatedB
enable a visual inspection of the pump while it is runningC
insure a proper alignment of the pump coupling to the driverD
accommodate for friction between the impeller and the easing
考题
单选题Which of the listed statements is correct concerning the starting of centrifugal pumps?（）A
They should always be started with the discharge valve closedB
They should always be started with the discharge valve openedC
A priming pump is always required to flood the impeller suctionD
They should always be started with the sealing line valves closed
考题
单选题The basic function of the centrifugal pump impeller is to （）.A
directly increase the pressure of the liquid being pumpedB
directly increase the velocity of the liquid being pumpedC
convert the potential energy of the liquid to kinetic energyD
separate air from the liquid being pumped
考题
单选题Most pump manufacturers recommend that the suction piping dimension for centrifugal pumps be （）.A
one size smaller than the pump suction nozzleB
the same size as the pump suction nozzleC
one size larger than the pump suction nozzleD
installed with a short radius elbow at the pump
考题
单选题Which of the following pumps belongs to centrifugal pump?（）A
Piston pumpB
Screw pumpC
Diffuser pumpD
Water-ring pump
考题
单选题A centrifugal pump produces flow with a resulting discharge head by energy conversionIt is typical for the energy conversion to follow the order of （）.A
mechanical energy to kinetic energy to potential energyB
mechanical energy to potential energy to kinetic energyC
potential energy to mechanical energy to kinetic energyD
kinetic energy to mechanical energy to potential energy
考题
单选题A centrifugal pump produces the required pressure energy by means of a rotating （） provided with vanes.A
propellerB
impellerC
circumferenceD
screw
考题
单选题To maintain design discharge pressure from a centrifugal pump, the design clearance must be maintained between the （）.A
shaft and impellerB
motor and pump shaftC
casing and impeller wearing ringsD
lantern ring and impeller
考题
单选题On modern ships, centrifugal pump with a self-primer has replaced reciprocating pump as bilge pump because（）A
centrifugal pump is cheaper than reciprocating pumpB
the size of centrifugal pump with same capacity is smaller than that of reciprocating pumpC
centrifugal pump makes maintenance easier than reciprocating pump doesD
all of the above
考题
单选题Some of the energy fed into the pump will be dissipated as （） due to mechanical inefficiencies, the remainder will be converted into pressure rise and fluid velocity.A
hydraulic headB
static headC
heat energyD
steam
考题
单选题The amount of fluid delivered by a centrifugal pump can be regulated by （）.A
throttling the pressure lineB
changing the speed of the rotorC
either A or BD
None of the above is tree
考题
单选题Which of the following centrifugal pump components converts the liquid kinetic energy of velocity to the potential energy of pressure?（）A
ImpellerB
Electric motorC
VoluteD
Eye
热门标签
最新试卷