A.reduce radial thrust to the impeller
B.double the liquid velocity through the pump when compared to a single volute
C.reduce hydraulic end thrust
D.provide the effect of multi-staging
您可能感興趣的試卷
你可能感興趣的試題
A.dirt will cause corrosion of bearing
B.bearings will leak oil excessively
C.dirt is very abrasive when mixed with grease
D.grease will become inflammable
A.promote refrigerant dehydration
B.be absorbed in the receiver
C.cause low condensing pressure
D.carry moisture and lead to corrosion
A.frosting of the liquid line
B.higher than normal head pressure
C.a clear sight glass
D.abnormally cold reefer boxes
A.The hose should not be twisted
B.The hose should be protected with a sleeve if it is subjected to rubbing
C.There should be some slack in the hose
D.All of the above
A.acid
B.fuel oil
C.sediment
D.water
最新試題
If the suction pressure at the refrigeration compressor is below normal, the cause can be（）.
The rate of heat transfer from a hot region to a cold region is affected most by the （）.
When the steering gear is in operation, you should （）.
Low compressor head pressure in a refrigeration system can be caused by（）.
If you are given the job of adding hydraulic fluid to a mooring winch, and are not certain as to the type of fluid to use, you should （）.
The rate of heat transfer between the hot and cold fluids passing through a shell-and-tube type heat exchanger will （）.
The output volume of a positive fixed displacement pump can be changed only by （）.
An increasing head pressure in a refrigeration system, without any corresponding change in the cooling water inlet temperature, would probably be caused by （）.
Which of the following statements is correct concerning heat transfer?（）
The major source of chemical contaminants in hydraulic fluid is （）.