A.a high suction head
B.rotating rings
C.badly worn bearings
D.a loose stuffing box gland
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A.solenoid valve to seize
B.compressor to hunt
C.formation of flash gas in the liquid line
D.expansion valve to freeze open
A.insufficient condenser cooling water
B.excessive condenser cooling water
C.air in the refrigeration system
D.excessive refrigerant in the system
A.Thermal expansion valve frozen open
B.Suction gas heat exchanger bypassed
C.Condenser clogged or fouled
D.High pressure cutout switch inoperative
A.noise and vibration
B.an increase in discharge pressure
C.an increase in suction pressure
D.lifting of the relief valve
A.insufficient cooling water flow to the condenser
B.a low refrigerant charge in the system
C.the liquid valve is open too much
D.high evaporator superheat
最新試題
A gradual decrease in the discharge pressure of an operating hydraulic pump can be caused by （）.
The control mode in which the final control element is moved from one of two flexed positions to the other is known as （）.
An internal bypass is provided on some hydraulic system suction strainers to help reduce the possibility of （）.
Which of the following problems could cause the high pressure cutout switch to shut down the compressor in a refrigeration system?（）
When the steering gear is in operation, you should （）.
A pressure drop through the refrigerant liquid line may cause （）.
A salinity indicator is used to determine the （）.
Which of the listed pumps is NOT a positive displacement pump?（）
The general purpose of a heat exchanger is to （）.
The rate of heat transfer between the hot and cold fluids passing through a shell-and-tube type heat exchanger will （）.