A.insufficient lube oil circulating through the system
B.excessive circulation of lube oil through the system
C.insufficient refrigerant in the system
D.an overworked compressor
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A.decreased clearances between rotating parts
B.decreased slippage to the suction side of the pump
C.air binding in the discharge ports
D.erosion and excessive wear
A.a shortage of refrigerant in the system
B.air in the system
C.an accumulation of liquid refrigerant in the crankcase
D.a shortage of oil in the crankcase
A.ram relief valves bypass oil to stop rudder movement
B.six-way valve shifts to the neutral flow position
C.steering pump electric motor is de - energized by the transfer switch
D.follow-up gear takes the hydraulic pump off stroke
A.maintain a preset pressure on the line
B.closely regulate the amount of flow
C.relieve excessive pressure on the line
D.allow flow in one direction only
A.insufficient load
B.excessively high oil viscosity
C.relief-valve pressure setting too high
D.reservoir level being maintained two inches above normal
最新試題
One cause of high head pressure occurring in a refrigeration system can be （）.
A pressure drop through the refrigerant liquid line may cause （）.
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?（）
A salinity indicator is used to determine the （）.
On tank vessels equipped with power operated cargo tank valves, the type of power operator most commonly used is （）.
Heavy wear in a particular area of the inner circumference of a packing ring may be caused by （）.
Which of the following problems could cause the high pressure cutout switch to shut down the compressor in a refrigeration system?（）
The general purpose of a heat exchanger is to （）.
Thermostatic expansion valves can be adjusted for （）.
Pitting in the suction areas of a centrifugal pump bronze impeller is usually caused by （）.