A.unusual vibration
B.excessive worn parts
C.abnormal pressure
D.any of the above
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A.Relief valve
B.Direction control valve
C.Stop valve
D.Pressure control valve
A.flow of oil
B.pressure of oil
C.A and B
D.temperature of oil
A.Relief valves
B.Check valves
C.Safety valves
D.Reducing valve
A.Hydraulic pumps
B.Valve
C.Hydraulic cylinders
D.Hydraulic motors
A.The hydraulic pumps
B.Valves
C.Hydraulic cylinders
D.Hydraulic motors
最新試題
Which of the listed pumps is NOT a positive displacement pump?（）
A pressure drop through the refrigerant liquid line may cause （）.
The major source of chemical contaminants in hydraulic fluid is （）.
A salinity indicator is used to determine the （）.
Thermostatic expansion valves can be adjusted for （）.
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（）.
Which of the problems listed would came the discharge temperature of an R-12 refrigeration compressor to increase?（）
The output volume of a positive fixed displacement pump can be changed only by （）.
The usual symptoms of cavitation in a centrifugal pump is （）.