A.broken inlet valves
B.broken discharge valves
C.pulsations in the air distribution system
D.overloading of the air distribution system
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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
If the viscosity of the liquid being transferred remains constant as the discharge pressure increases, the rotary pump （）.
The usual symptoms of cavitation in a centrifugal pump is （）.
A gradual decrease in the discharge pressure of an operating hydraulic pump can be caused by （）.
An excessive charge of refrigerant in an air-cooled refrigeration system can cause （）.
The rate of heat transfer between the hot and cold fluids passing through a shell-and-tube type heat exchanger will （）.
Which of the following problems could cause the high pressure cutout switch to shut down the compressor in a refrigeration system?（）
Pitting in the suction areas of a centrifugal pump bronze impeller is usually caused by （）.
One cause of high head pressure occurring in a refrigeration system can be （）.
Who is responsible for ensuring that someone is assigned to close the watertight doors in an emergency?（）
The control mode in which the final control element is moved from one of two flexed positions to the other is known as （）.