A.misalignment or worn main bearings
B.insufficient cylinder lubrication
C.defective or poorly fitted valves
D.all of the above
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A.They make it easier to replace the pump shaft packing
B.They can be economically replaced as they wear out
C.They can be removed when it is necessary to lighten the weight of the pump
D.They increase the strength of the shaft
A.superheated
B.saturated
C.condensed
D.convected
A.radially from the shaft
B.parallel to each other and to the shaft
C.parallel to each other but at a right angle to the shaft
D.at an angle to each other and to the shaft
A.3 or 5
B.5 or 7
C.7 or 9
D.9 or 11
A.sensible heat
B.latent heat
C.total heat
D.residual heat
最新試題
Which of the following problems could cause the high pressure cutout switch to shut down the compressor in a refrigeration system?（）
An internal bypass is provided on some hydraulic system suction strainers to help reduce the possibility of （）.
If the head pressure of a reciprocating refrigeration compressor is excessive, （）.
Which of the listed pumps is NOT a positive displacement pump?（）
Which of the following statements is correct concerning heat transfer?（）
Who is responsible for ensuring that someone is assigned to close the watertight doors in an emergency?（）
A gradual decrease in the discharge pressure of an operating hydraulic pump can be caused by （）.
If you are given the job of adding hydraulic fluid to a mooring winch, and are not certain as to the type of fluid to use, you should （）.
A pressure drop through the refrigerant liquid line may cause （）.
The control mode in which the final control element is moved from one of two flexed positions to the other is known as （）.