更多"Centrifugal pumps, however, can be "的相关试题:
[单项选择]Centrifugal pumps can be designed with a number of impellers （） to attain a high final delivery pressure.
A. in series
B. in parallel
C. either A or B
D. None of the above is tree
[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]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]Centrifugal pumps have what advantage(s) over reciprocating pumps?（）.
A. They are less expensive
B. They are smaller for equivalent pumping ability
C. They pump more cargo in less time
D. All of the above
[单项选择]Centrifugal pumps are non-positive and a fairly （） unit.
A. low pressure
B. low discharge
C. low speed
D. high pressure
[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]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 （）.
A. increase speed
B. increase the size of the cardent assembly
C. reduce wearing ring clearances
D. change the pump to a "close coupled" arrangement
[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]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
[单项选择]A centrifugal pump can’t supply water after startingYou should check （）.
A. priming water
B. power supply
C. packing gland
D. bearing lubrication
[单项选择]The pumps employed on board ship can be divided into two main categories ie（） pumps and centrifugal pumps.
A. gear
B. nonpositive displacement
C. positive displacement
D. rotary
[单项选择]Who can contact the Designed Person?（）
A. the designated person
B. the captain
C. all senior officer
D. all officers and crew
[单项选择]Gear pumps are of positive displacement type pumps because they discharge a near constant amount of liquid （） pressure.
A. depending on
B. in relative to
C. regardless of
D. because of
[单项选择]The Shipowner can，however，exempt himself from liability for（），but if he wishes to do so，he must use clear and unambiguous language.
A. seaworthy
B. seaworthiness
C. unseaworthy
D. unseaworthiness
[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]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]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
