更多"A spring-loaded centrifugal flyweig"的相关试题:
[单项选择]Which of the following centrifugal pump components converts the liquid kinetic energy of velocity to the potential energy of pressure?（）
A. Impeller
B. Electric motor
C. Volute
D. Eye
[单项选择]A centrifugal pump vibrates excessively during operationUpon disassembling the pump it is found that the impeller is out of balanceWithout an available spare, you should （）.
A. drill holes through the heavy side of the impeller until it balances
B. weld counterweights to the light side of the impeller
C. remove metal from the heavy side by machining in a lathe
D. acid wash and serape the heavy side until it balances
[单项选择]The centrifugal pump component responsible for converting the mechanical energy of the liquid being pumped, to that of kinetic energy is the （）.
A. electric motor
B. volute
C. impeller
D. diffusion nozzle
[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]The basic function of the centrifugal pump impeller is to （）.
A. directly increase the pressure of the liquid being pumped
B. directly increase the velocity of the liquid being pumped
C. convert the potential energy of the liquid to kinetic energy
D. separate air from the liquid being pumped
[单项选择]Centrifugal pumps are popular because they are very simple in construction,and produce smooth, constant, （） discharge.
A. non-pulsating
B. pulsating
C. positive
D. non-positive
[单项选择]A multistage centrifugal pump can be BEST described as having （）.
A. two or more impellers housed together in one casing and mounted on a single shaft
B. a single stepped impeller mounted in a progressively staged casing
C. a large radial clearance between the impeller and casing to prevent overheating due to
D. an increase in the discharge velocity of the liquid with a corresponding decrease in pressure through the stages
[单项选择]With respect to centrifugal pump impellers, which of the following descriptions represents the correct centrifugal pump classification? （）
A. Single stage or multistage
B. High pressure or low pressure
C. Open or close coupled
D. Horizontal or vertical
[单项选择]The usual symptoms of cavitation in a centrifugal pump is （）.
A. noise and vibration
B. an increase in discharge pressure
C. an increase in suction pressure
D. lifting of the relief valve
[单项选择]A centrifugal bilge pump requires priming （）.
A. primarily to lubricate the shaft seals
B. due to the inability of this type of pump to lift water to cover the suction (eye) of the impeller
C. to initially unload the pump by having its head pressure equal to discharge pressure
D. in order to overcome the potential energy of water in the discharge line
[单项选择]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 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 discharge rate or capacity of a centrifugal pump will vary directly as the （）.
A. change in the impeller diameter
B. square of the impeller radius
C. cube of the impeller diameter
D. impeller efficiency for large changes in its size
[单项选择]When starting a centrifugal pump, the discharge valve should be （）.
A. closed
B. opened fully
C. cracked open
D. partly open
[单项选择]High-speed rotation in a centrifugal purifier can produce a force （） the force of gravity.
A. many thousand times larger than
B. the same as
C. many thousand times smaller
D. none of the above
[单项选择]High-speed rotating in a centrifugal purifier can produce a force （） larger than the force of gravity.
A. many thousand times
B. between times
C. one time
D. at times
[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]If the capacity of a centrifugal pump decreases gradually over a long period of time, you should replace the （）.
A. packing gland
B. mechanical seals
C. lantern rings
D. wearing rings
[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]Shaft sealing in a centrifugal pump can be effected by （）.
A. the mechanical seal
B. packed stuffing boxes
C. either A or B
D. neither A nor B
