A.fill the unit with saltwater
B.fill the unit with de-scaling compound
C.completely drain the unit
D.tightly seal the unit to exclude air
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A.dischargeendbeingsmallerthanthesuctionend
B.smallsizeofimpeller
C.lackofmovingparts
D.easeatwhichthewearingringsmaybechanged
A.fusion
B.vaporization
C.sublimation
D.condensation
A.Overcoming sliding friction
B.Overcoming rolling friction
C.Overcoming fluid friction
D.Overcoming oil wedge friction
A.weight designation
B.viscosity index
C.pour point
D.thermal change value
A.fusion
B.vaporization
C.condensation
D.sublimation
最新試題
The usual symptoms of cavitation in a centrifugal pump is （）.
If the thermal bulb of an expansion valve is incorrectly placed at the center of the coil instead of the end, it will （）.
The control mode in which the final control element is moved from one of two flexed positions to the other is known as （）.
Heavy wear in a particular area of the inner circumference of a packing ring may be caused by （）.
A salinity indicator is used to determine the （）.
The rate of heat transfer from a hot region to a cold region is affected most by the （）.
The amount of fluid friction or internal friction inherent in a mineral lubricating oil is reflected as a measure of its （）.
A salinity indicator is used to determine the （）.
Which of the problems listed would came the discharge temperature of an R-12 refrigeration compressor to increase?（）
If the relief valve on the discharge side of a hydraulic pump lifts, the cause could be （）.