Which of the following pumps are self-priming, and can deal with liquid from a level below the pump（）
(1) ejector
(2) screw
(3) centrifugal
A.(1)only
B.(1)and(2)
C.(1),(2)and(3)
D.(2)and(3)
您可能感興趣的試卷
你可能感興趣的試題
A.centrifugal
B.plunger
C.injector
D.water
A.discharges into a gradually widening channel
B.has stationary diffuser vanes
C.produces no kinetic energy
D.All of the above are true
A.Piston pump
B.Screw pump
C.Diffuser pump
D.Water-ring pump
A.pump entry branch
B.outlet pipe
C.impeller
D.None of the above is true
A.to fill 2 tanks at the same time
B.to use pump at a higher pressure
C.to return liquid to suction side if discharge valve is closed
D.All of the above are true
最新試題
The major source of chemical contaminants in hydraulic fluid is （）.
A gradual decrease in the discharge pressure of an operating hydraulic pump can be caused by （）.
The control mode in which the final control element is moved from one of two flexed positions to the other is known as （）.
If you are given the job of adding hydraulic fluid to a mooring winch, and are not certain as to the type of fluid to use, you should （）.
The amount of fluid friction or internal friction inherent in a mineral lubricating oil is reflected as a measure of its （）.
Thermostatic expansion valves can be adjusted for （）.
When the steering gear is in operation, you should （）.
The output volume of a positive fixed displacement pump can be changed only by （）.
The temperature differential occurring between the inlet temperature of the fluid to be cooled and the outlet temperature of the cooling medium in a shell-and-tube heat exchanger is greatest in which of the flow designs listed?（）
Which of the problems listed would came the discharge temperature of an R-12 refrigeration compressor to increase?（）