A.The pump delivers full capacity when started, but gradually slackens off toan abnormally low flow
B.The pump packing gland overheats after short operating periods
C.The motor over-current protective device continually shuts the pump down
D.Pounding noises can be heard at the pump suction chest
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A.diameter of the discharge piping, with all other factors remaining the same
B.diameter of the suction piping, with all other factors remaining the same
C.width of the impeller only
D.diameter of the impeller
A.run continuously
B.not start
C.have high discharge pressure
D.short cycle on the high pressure switch
A.Electrical energy
B.Thermal energy
C.Potential energy
D.Kinetic energy
A.sliding block
B.pintle
C.reaction ring
D.tilting box or swash plate
A.overfeeding of the expansion valve
B.damage to the condenser
C.constant running of the compressor
D.flooding of the receiver
最新試題
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?（）
A pressure drop through the refrigerant liquid line may cause （）.
An increasing head pressure in a refrigeration system, without any corresponding change in the cooling water inlet temperature, would probably be caused by （）.
One cause of high head pressure occurring in a refrigeration system can be （）.
A grease gun is generally used to lubricate a （）.
The major source of chemical contaminants in hydraulic fluid is （）.
Low compressor head pressure in a refrigeration system can be caused by（）.
Which of the following statements is correct concerning heat transfer?（）
If the head pressure of a reciprocating refrigeration compressor is excessive, （）.
A salinity indicator is used to determine the （）.