A.pump bearings in poor condition
B.excessively worn actuator-piston packing
C.broken directional control valve centering springs
D.low hydraulic oil viscosity
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A.a spring
B.an electromagnet
C.the force of gravity
D.refrigerant pressure
A.viscosity will decrease
B.volume will increase
C.volume will decrease
D.pour point will be reduced
A.a shortage of refrigerant
B.the compressor running continuously
C.liquid refrigerant returning to the compressor
D.the compressor short cycling on the high pressure cutout
A.evaporation is accomplished in a vacuum
B.due to the higher temperature of the incoming feed
C.due to the latent heat of evaporation principle
D.evaporation in a submerged medium produces more distillate
A.the bow
B.the stem
C.the port side
D.the starboard side
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 （）.
A pressure drop through the refrigerant liquid line may cause （）.
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 （）.
A gradual decrease in the discharge pressure of an operating hydraulic pump can be caused by （）.
An internal bypass is provided on some hydraulic system suction strainers to help reduce the possibility of （）.
One cause of high head pressure occurring in a refrigeration system can be （）.
Thermostatic expansion valves can be adjusted for （）.
Low compressor head pressure in a refrigeration system can be caused by（）.
Which of the following problems could cause the high pressure cutout switch to shut down the compressor in a refrigeration system?（）