A.prevent the gear box from leaking
B.prevent the oil from becoming inflammable
C.make sure it has not become contaminated
D.make sure the motor bearings are lubricated
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A.slightly opened
B.throttled
C.fully opened
D.halfway opened
A.increase speed
B.increase the size of the cardent assembly
C.reduce wearing ring clearances
D.change the pump to a "close coupled" arrangement
A.Chemical energy
B.Mechanical energy
C.Thermal energy
D.Electrical energy
A.air bubbles in the sight glass
B.any leaks in the system
C.over-travel in the rudder angle indicator
D.lost motion in the rams
A.The pump delivers full capacity when started, but gradually slackens off toan abnormally low flow
B.The pump packing gland overheats after short operating periods
C.The motor over-current protective device continually shuts the pump down
D.Pounding noises can be heard at the pump suction chest
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If the suction pressure at the refrigeration compressor is below normal, the cause can be().
If the viscosity of the liquid being transferred remains constant as the discharge pressure increases, the rotary pump ().
A pressure drop through the refrigerant liquid line may cause ().
Pitting in the suction areas of a centrifugal pump bronze impeller is usually caused by ().
If the head pressure of a reciprocating refrigeration compressor is excessive, ().
If the relief valve on the discharge side of a hydraulic pump lifts, the cause could be ().
An internal bypass is provided on some hydraulic system suction strainers to help reduce the possibility of ().
Low compressor head pressure in a refrigeration system can be caused by().
A grease gun is generally used to lubricate a ().
A salinity indicator is used to determine the ().