A.Protects against suction valve float
B.Provides a positive pressure on the air inlet valves
C.Prevents lubricating oil contamination of the compressed air supply
D.Protects against the damaging effects of airborne solid particles
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A.warm-up allows the hydraulic system to become charged with oil
B.warm-up allows the relief valves to be properly tested
C.hydraulic strainers operate only during the warm-up period
D.hydraulic fluid must be at the proper viscosity
A.are exposed to a vacuum
B.come in contact with extremely hot surfaces
C.are reduced in temperature to just above the pour point
D.become extremely agitated or aerated
A.weight
B.internal friction
C.demulsibility
A.Extensive centrifuging
B.Wax content
C.Water content
D.Acid content
A.Viscosity will increase as temperature increases
B.Viscosity is a measure of a fluid s internal resistance to flow
C.Viscosity will decrease as temperature decreases
D.Viscosity is not dependent on temperature
最新試題
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 （）.
The amount of fluid friction or internal friction inherent in a mineral lubricating oil is reflected as a measure of its （）.
An increasing head pressure in a refrigeration system, without any corresponding change in the cooling water inlet temperature, would probably be caused by （）.
If the head pressure of a reciprocating refrigeration compressor is excessive, （）.
The usual symptoms of cavitation in a centrifugal pump is （）.
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 （）.
Low compressor head pressure in a refrigeration system can be caused by（）.
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Pitting in the suction areas of a centrifugal pump bronze impeller is usually caused by （）.