单项选择题
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 knocking sound from one cylinder of an operating air ...
单项选择题A knocking sound from one cylinder of an operating air compressor indicates （）.
A.a defective or broken high pressure un-loader B.a loose valve plate C.excessive overload D.no compression
Rotation of the steering wheel on the navigation bridge...
单项选择题Rotation of the steering wheel on the navigation bridge initiates oil pressure being applied to the steering gear rams by （）.
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
Which characteristic or condition will have the greates...
单项选择题Which characteristic or condition will have the greatest effect on increasing a hydraulic oils viscosity?（）
A.Pour point B.Cloud point C.Vacuum D.Pressure
