A.hydraulic fluid contamination
B.excessive fluid friction
C.turbulent fluid flow
D.fluid pressure surges
您可能感興趣的試卷
你可能感興趣的試題
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
A.repack all valve stems
B.lubricate it prior to use
C.replace the foundation bolts
D.balance the warping heads
最新試題
An excessive charge of refrigerant in an air-cooled refrigeration system can cause （）.
The temperature differential occurring between the inlet temperature of the fluid to be cooled and the outlet temperature of the cooling medium in a shell-and-tube heat exchanger is greatest in which of the flow designs listed?（）
Which of the problems listed would came the discharge temperature of an R-12 refrigeration compressor to increase?（）
Heavy wear in a particular area of the inner circumference of a packing ring may be caused by （）.
An increasing head pressure in a refrigeration system, without any corresponding change in the cooling water inlet temperature, would probably be caused by （）.
One cause of high head pressure occurring in a refrigeration system can be （）.
A gradual decrease in the discharge pressure of an operating hydraulic pump can be caused by （）.
If the suction pressure at the refrigeration compressor is below normal, the cause can be（）.
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, （）.