A.throttling the pressure line
B.changing the speed of the rotor
C.either A or B
D.None of the above is tree
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A.reciprocating pumps
B.positive displacement pumps
C.centrifugal pumps
D.centripetal pumps
A.positive displacement
B.ejector
C.centrifugal
D.air compressor
A.single screw pump
B.double-screw pump
C.triple screw pump
D.centripetal pump
A.steady
B.in pulsation
C.continuous
D.large
A.propeller
B.impeller
C.circumference
D.screw
最新試題
Which of the following statements is correct concerning heat transfer?（）
Which of the problems listed would came the discharge temperature of an R-12 refrigeration compressor to increase?（）
Which of the listed pumps is NOT a positive displacement pump?（）
An excessive charge of refrigerant in an air-cooled refrigeration system can cause （）.
The rate of heat transfer between the hot and cold fluids passing through a shell-and-tube type heat exchanger will （）.
The control mode in which the final control element is moved from one of two flexed positions to the other is known as （）.
A gradual decrease in the discharge pressure of an operating hydraulic pump can be caused by （）.
A salinity indicator is used to determine the （）.
A grease gun is generally used to lubricate a （）.
When the steering gear is in operation, you should （）.