A.maintain a preset pressure on the line
B.closely regulate the amount of flow
C.relieve excessive pressure on the line
D.allow flow in one direction only
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A.insufficient load
B.excessively high oil viscosity
C.relief-valve pressure setting too high
D.reservoir level being maintained two inches above normal
A.a defective or broken high pressure un-loader
B.a loose valve plate
C.excessive overload
D.no compression
A.regulating the oil flow with the six-way valve
B.moving the automatic differential valve
C.moving the receiving tele-motor which regulates the two-way valve
D.varying the angle of a tilting box or eccentricity of a floating ring
A.Pour point
B.Cloud point
C.Vacuum
D.Pressure
A.set for maximum torque
B.on the purge and vent stroke
C.in the neutral position
D.rotating backwards
最新試題
The major source of chemical contaminants in hydraulic fluid 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 （）.
One cause of high head pressure occurring in a refrigeration system can be （）.
When a refrigeration compressor has developed a high head pressure as a result of a refrigerant overcharge, you should （）.
The control mode in which the final control element is moved from one of two flexed positions to the other is known as （）.
Pitting in the suction areas of a centrifugal pump bronze impeller is usually caused by （）.
The general purpose of a heat exchanger is to （）.
An internal bypass is provided on some hydraulic system suction strainers to help reduce the possibility of （）.
A grease gun is generally used to lubricate a （）.