A.non-pulsating
B.pulsating
C.positive
D.non-positive
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A.injection valve
B.relief valve
C.discharge valve
D.inlet filter
A.gear
B.vane
C.screw
D.centrifugal
A.low pressure
B.low discharge
C.low speed
D.high pressure
A.positive displacement
B.non-positive displacement
C.mixed-flow
D.axial-flow
A.Reciprocating pumps
B.Rotary pumps
C.Centrifugal pumps
D.Gear pumps
最新試題
The control mode in which the final control element is moved from one of two flexed positions to the other is known as （）.
If the suction pressure at the refrigeration compressor is below normal, the cause can be（）.
Heavy wear in a particular area of the inner circumference of a packing ring may be caused by （）.
Low compressor head pressure in a refrigeration system can be caused 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?（）
When the steering gear is in operation, you should （）.
The output volume of a positive fixed displacement pump can be changed only by （）.
Which of the problems listed would came the discharge temperature of an R-12 refrigeration compressor to increase?（）
A pressure drop through the refrigerant liquid line may cause （）.
A grease gun is generally used to lubricate a （）.