A.blue
B.green
C.orange
D.purple
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你可能感興趣的試題
A.excessive condenser cooling water
B.warm food in the refrigerator
C.a shortage of refrigerant
D.s shortage of compressor oil
A.either all the way open or all the way closed
B.normally open
C.throttled depending on load
D.controlled by suction pressure
When a hydraulic vane pump is working, which of the following is in contact with the vanes?（）
(1) the rotor
(2) the internal surface of the housing
(3) the external surface of the housing
A.(1) only
B.(2) only
C.(1) and (2)
D.(1), (2) and (3)
A.Control of evaporation
B.A separate means to prevent feed-water contamination
C.Power circulating pump
D.Super-heater
A.check and regulate the water level
B.close the air cock once fires are lit
C.blowdown the gage glass
D.crack the steam stop to assure protective steam flow
最新試題
The output volume of a positive fixed displacement pump can be changed only by （）.
The usual symptoms of cavitation in a centrifugal pump is （）.
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?（）
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 grease gun is generally used to lubricate a （）.
Which of the following problems could cause the high pressure cutout switch to shut down the compressor in a refrigeration system?（）
On tank vessels equipped with power operated cargo tank valves, the type of power operator most commonly used is （）.
When a refrigeration compressor has developed a high head pressure as a result of a refrigerant overcharge, you should （）.
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 （）.