A.In order for a fluid to be pumped, a fluid must be made to flow
B.A substance must be cold in order for it to be pumped
C.The kinetic energy imparted by the pump can be used to force a liquid through a hydraulic system
D.A pump must receive its energy from an external source
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A.one size smaller than the pump suction nozzle
B.the same size as the pump suction nozzle
C.one size larger than the pump suction nozzle
D.installed with a short radius elbow at the pump
A.first stage flash chamber
B.second stage flash chamber
C.first stage after condenser
D.second stage distilling condenser
A.system is low on refrigerant
B.high pressure cutout switch is improperly adjusted
C.discharge valves are leaking slightly
D.discharge valves are leaking excessively
A.leaky discharge valves on the LP cylinder
B.leaky discharge valves on the HP cylinder
C.insufficient intercooler cooling
D.low ambient air pressure
A.one size larger than the pump discharge nozzle
B.the same size as the pump discharge nozzle
C.one size smaller than the pump discharge nozzle
D.installed with a short radius elbow at the pump
最新試題
If the suction pressure at the refrigeration compressor is below normal, the cause can be（）.
Pitting in the suction areas of a centrifugal pump bronze impeller is usually caused by （）.
A gradual decrease in the discharge pressure of an operating hydraulic pump can be caused by （）.
Which of the listed pumps is NOT a positive displacement pump?（）
An excessive charge of refrigerant in an air-cooled refrigeration system can cause （）.
The output volume of a positive fixed displacement pump can be changed only by （）.
If the thermal bulb of an expansion valve is incorrectly placed at the center of the coil instead of the end, it will （）.
Which of the following problems could cause the high pressure cutout switch to shut down the compressor in a refrigeration system?（）
Low compressor head pressure in a refrigeration system can be caused by（）.
An internal bypass is provided on some hydraulic system suction strainers to help reduce the possibility of （）.