更多"The usual symptoms of cavitation in"的相关试题:
[单项选择]Cavitation erosion in the cooling water system of a diesel engine usually occurs at the pump impeller, and on the waterside of the （）
A. fuel nozzle holders
B. exhaust value guides
C. engine cylinder liners
D. low temperature and a low viscosity
[单项选择]Why are removable sleeves installed on centrifugal pump shafts?（）
A. They make it easier to replace the pump shaft packing
B. They can be economically replaced as they wear out
C. They can be removed when it is necessary to lighten the weight of the pump
D. They increase the strength of the shaft
[单项选择]A centrifugal pump attempting to develop flow against a closed discharge valve has a/an （）.
A. capacity of 0%
B. efficiency of 100%
C. internal slippage of 0%
D. shut off horsepower rating of 100%
[单项选择]If a centrifugal bilge pump were continually operated with the discharge valve closed the （）.
A. motor overload would open
B. relief valve would open
C. pump would eventually overheat
D. motor would overheat
[单项选择]If a centrifugal pump were continually operated with the discharge valve closed, the （）.
A. motor controller overload would open
B. pump would eventually overheat
C. relief valve would continuously cycle open
D. motor would overheat
[单项选择]A double suction centrifugal pump impeller has been installed in the reverse direction, and will （）.
A. have a greater head capacity
B. operate with increased impeller efficiency
C. discharge through the suction side of the pump casing
D. require more power to run the shaft
[单项选择]A spring-loaded centrifugal flyweight governor responds to reduced engine load with an immediate increase in （）
A. pilot valve oil pressure
B. speeder spring force
C. compensation needle valve clearance
D. centrifugal force on the flyweights
[单项选择]What is a characteristic of all centrifugal cargo pumps? （）
A. They are self-priming
B. Decreasing the speed of rotation will decrease the discharge pressure
C. Opening the discharge valve wider will increase the discharge pressure
D. All of the above
[单项选择]For optimum results, centrifugal purification of heavy fuel oil should be accomplished with the fuel at the lowest practicable（）
A. throughput
B. additive percent
C. cetane number
D. TBN number
[单项选择]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 energy
B. mechanical energy to potential energy to kinetic energy
C. potential energy to mechanical energy to kinetic energy
D. kinetic energy to mechanical energy to potential energy
[单项选择]While flowing through the volute in a centrifugal pump, part of the （） energy of the liquid is converted to （） energy.
A. kinetic；pressure
B. kinetic；essential
C. pressure；kinetic
D. pressure；height
[单项选择]Under centrifugal pumps are the volute, diffuser, mixed-flow, axial flow and （） or regenerative types.
A. reciprocating
B. hydraulic
C. turbine
D. vane
[单项选择]To operate a centrifugal fire pump at reduced capacity, you should （）.
A. readjust the relief valve
B. throttle the suction line
C. throttle the discharge valve
D. open the priming line
[单项选择]A centrifugal pump may fail to deliver water when first started if the （）.
A. water seal pipe is plugged
B. pump is not primed
C. seal ring is improperly located
D. impeller is flooded
[单项选择]A centrifugal fuel oil purifier should be shut down if （）
A. more sealing water is needed
B. the cover clamp needs tightening
C. the purifier has a bad vibration when started
D. water is discharged from the overflow line
[单项选择]The advantage of a centrifugal pump as compared with a reciprocating pump is that （）.
A. discharge is continuous
B. it has no internal valves
C. upon accidental closing of discharge valve, excessive pressure will not build up
D. all of the above are true
[单项选择]Increasing the speed of a centrifugal pump will result in an increase in its capacity in its capacityAnother means of increasing the capacity pump is to increase the（）
A. diameter of the discharge piping, with all other factors remaining the same
B. diameter of the suction piping, with all other factors remaining the same
C. width of the impeller only
D. diameter of the impeller
[单项选择]The amount of fluid delivered by a centrifugal pump can be regulated by （）.
A. throttling the pressure line
B. changing the speed of the rotor
C. either A or B
D. None of the above is tree
[单项选择]The discharge head of a centrifugal pump will vary directly with the （）.
A. change in impeller diameter
B. square of the impeller diameter
C. cube of the impeller diameter
D. impeller efficiency for large changes in the size of the impeller
