A.variable stroke pumps
B.multistage pumps
C.positive displacement pumps
D.triple-ported pumps
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A.mixed-flow pump
B.axial-flow pump
C.centrifugal pump
D.displacement pump
A.on top cover
B.on sides of bowl
C.in drain line on the discs
D.on the discs
A.oil
B.sea water
C.refrigerant
D.fresh water
A.a flash generator
B.a flash evaporator
C.a vacuum boiling evaporator
D.a boiler
A.lower than
B.higher than
C.as much as
D.the same as
最新試題
A grease gun is generally used to lubricate a （）.
The general purpose of a heat exchanger is to （）.
Heavy wear in a particular area of the inner circumference of a packing ring may be caused by （）.
If the suction pressure at the refrigeration compressor is below normal, the cause can be（）.
The usual symptoms of cavitation in a centrifugal pump is （）.
Thermostatic expansion valves can be adjusted for （）.
A gradual decrease in the discharge pressure of an operating hydraulic pump can be caused by （）.
The rate of heat transfer from a hot region to a cold region is affected most by the （）.
Which of the problems listed would came the discharge temperature of an R-12 refrigeration compressor to increase?（）
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?（）