A.have a greater head capacity
B.operate with increased impeller efficiency
C.discharge through the suction side of the pump casing
D.require more power to run the shaft
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A.hydraulic fluid contamination
B.excessive fluid friction
C.turbulent fluid flow
D.fluid pressure surges
A.yearly
B.quarterly
C.monthly
D.daily
A.evaporator pressure decrease
B.evaporator coil over-feed
C.evaporator capacity increase
D.expansion valve diaphragm rupture
A.head capacity to improve
B.discharge to be reversed
C.efficiency to decrease
D.slippage to decrease
A.gums, acids, and varnishes
B.removed by cellulose type filters
C.neutralized by oil additives
D.not removed by absorbent filters
最新試題
The general purpose of a heat exchanger is to （）.
A grease gun is generally used to lubricate a （）.
Which of the following problems could cause the high pressure cutout switch to shut down the compressor in a refrigeration system?（）
Pitting in the suction areas of a centrifugal pump bronze impeller is usually caused by （）.
Thermostatic expansion valves can be adjusted for （）.
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 （）.
On tank vessels equipped with power operated cargo tank valves, the type of power operator most commonly used is （）.
Low compressor head pressure in a refrigeration system can be caused by（）.
If the head pressure of a reciprocating refrigeration compressor is excessive, （）.