A.acid formation
B.sludge formation
C.ice in the expansion valve
D.All of the above
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A.superheated outside the system
B.in contact with an open flame
C.heated to the boiling point
D.All of the above
A.Variable volumes can be obtained with gear pumps only by variation of the pump drive speed
B.A radial piston pump houses sliding pistons in a stationary cylinder block through which passes a rotating pintle or ported shaft
C.The amount of fluid displaced per revolution of an axial piston rotary pump is dependent on the angle formed between the cylinder block and valve plate
D.All of the above
A.transmit the rudder angle to the bridge indicator
B.prevent the control linkage from striking the stops when hard over
C.automatically purge all entrained air from the system
D.send hydraulic signals to the receiving unit
A.horizontally mounted
B.never fitted with intake filters
C.fitted with intercoolers
D.operated in an unloaded condition at all times
A.High pressure compressors are more efficient than low pressure compressors
B.Mechanical efficiency divided by compressor efficiency will equal the overall efficiency of the compressor unit
C.Two stage compressors are generally more efficient than single stage compressors
D.The volumetric efficiency is decreased in multistage compressors
最新試題
An increasing head pressure in a refrigeration system, without any corresponding change in the cooling water inlet temperature, would probably be caused by ().
Which of the following statements is correct concerning heat transfer?()
A pressure drop through the refrigerant liquid line may cause ().
The output volume of a positive fixed displacement pump can be changed only by ().
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 control mode in which the final control element is moved from one of two flexed positions to the other is known as ().
Heavy wear in a particular area of the inner circumference of a packing ring may be caused by ().
If the relief valve on the discharge side of a hydraulic pump lifts, the cause could be ().
A gradual decrease in the discharge pressure of an operating hydraulic pump can be caused by ().
When the steering gear is in operation, you should ().