A.broken inlet valves
B.broken discharge valves
C.pulsations in the air distribution system
D.overloading of the air distribution system
您可能感興趣的試卷
你可能感興趣的試題
A.warping head
B.fairlead
C.wildcat
D.capstan
A.system was overcharged with refrigerant
B.high pressure switch was improperly adjusted
C.expansion valve strainers were fouled
D.suction valves were leaking slightly
A.increased pump speed
B.excessive pump discharge pressure
C.too low of a tilting box angle
D.low pump speed
A.Lube oil passing through the system
B.Moisture or foreign matter collecting at the valve seat and orifice
C.Variable spring tension caused by the changing temperature
D.Frost on the liquid line
A.an immediate crankcase explosion
B.oil contamination in the compressed air
C.a decrease in compressor capacity
D.no immediate loss of the compressed air capacity
最新試題
A pressure drop through the refrigerant liquid line may cause （）.
A gradual decrease in the discharge pressure of an operating hydraulic pump can be caused by （）.
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?（）
If the head pressure of a reciprocating refrigeration compressor is excessive, （）.
One cause of high head pressure occurring in a refrigeration system can be （）.
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 （）.
Low compressor head pressure in a refrigeration system can be caused by（）.
Which of the listed pumps is NOT a positive displacement pump?（）
The amount of fluid friction or internal friction inherent in a mineral lubricating oil is reflected as a measure of its （）.