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
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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
A.centerline of the pump and the level of the liquid in the suction well when the source of liquid is below the pump
B.centerline of the pump and the suction liquid level when the source of liquid is above the pump
C.centerline of the pump and the level of the discharge liquid
D.liquid levels of the suction and discharge
最新試題
If the viscosity of the liquid being transferred remains constant as the discharge pressure increases, the rotary pump （）.
Heavy wear in a particular area of the inner circumference of a packing ring may be caused by （）.
The major source of chemical contaminants in hydraulic fluid is （）.
The rate of heat transfer from a hot region to a cold region is affected most by the （）.
On tank vessels equipped with power operated cargo tank valves, the type of power operator most commonly used is （）.
Thermostatic expansion valves can be adjusted for （）.
One cause of high head pressure occurring in a refrigeration system can be （）.
The usual symptoms of cavitation in a centrifugal pump is （）.
Which of the following statements is correct concerning heat transfer?（）
The amount of fluid friction or internal friction inherent in a mineral lubricating oil is reflected as a measure of its （）.