A.maintain radial alignment between the pump impeller and casing
B.absorb all impeller shaft end thrust
C.prevent water leakage to the atmosphere
D.prevent wear of the pump casing and/or impeller
您可能感興趣的試卷
你可能感興趣的試題
A.psychrometer
B.salinometer
C.anemometer
D.sphygmomanometer
A.A large change of viscosity occurs with a minor change in temperature
B.No change in viscosity occurs with any change in temperature
C.Very little change in viscosity occurs with a significant change in temperature
D.The viscosity of the oil increases with an increase in temperature
A.pump would be very noisy
B.pump would vibrate excessively
C.pump would develop insufficient flow
D.stuffing box would leak excessively
A.gravity and feed oil cups
B.grease cups
C.hand during installation
D.leakage through the stuffing box
A.a needle gun
B.soap and water
C.a wire brush
D.a chipping hammer
最新試題
The control mode in which the final control element is moved from one of two flexed positions to the other is known as （）.
The rate of heat transfer from a hot region to a cold region is affected most by the （）.
A grease gun is generally used to lubricate a （）.
An excessive charge of refrigerant in an air-cooled refrigeration system can cause （）.
When a refrigeration compressor has developed a high head pressure as a result of a refrigerant overcharge, you should （）.
Which of the following problems could cause the high pressure cutout switch to shut down the compressor in a refrigeration system?（）
One cause of high head pressure occurring in a refrigeration system can be （）.
A pressure drop through the refrigerant liquid line may cause （）.
If the thermal bulb of an expansion valve is incorrectly placed at the center of the coil instead of the end, it will （）.
The general purpose of a heat exchanger is to （）.