A.Close radial clearance between impeller hub and casing
B.Low rotational speed of impeller
C.Removable end plate
D.Replaceable impeller and casing wearing rings
您可能感興趣的試卷
你可能感興趣的試題
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
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
最新試題
Low compressor head pressure in a refrigeration system can be caused by（）.
The usual symptoms of cavitation in a centrifugal pump is （）.
One cause of high head pressure occurring in a refrigeration system can be （）.
An internal bypass is provided on some hydraulic system suction strainers to help reduce the possibility of （）.
The major source of chemical contaminants in hydraulic fluid is （）.
Which of the listed pumps is NOT a positive displacement pump?（）
When the steering gear is in operation, you should （）.
If the thermal bulb of an expansion valve is incorrectly placed at the center of the coil instead of the end, it will （）.
The rate of heat transfer from a hot region to a cold region is affected most by the （）.
Heavy wear in a particular area of the inner circumference of a packing ring may be caused by （）.