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
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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
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The control mode in which the final control element is moved from one of two flexed positions to the other is known as （）.
If the relief valve on the discharge side of a hydraulic pump lifts, the cause could be （）.
A gradual decrease in the discharge pressure of an operating hydraulic pump can be caused by （）.
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Which of the following statements is correct concerning heat transfer?（）
The amount of fluid friction or internal friction inherent in a mineral lubricating oil is reflected as a measure of its （）.
The output volume of a positive fixed displacement pump can be changed only by （）.
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The rate of heat transfer between the hot and cold fluids passing through a shell-and-tube type heat exchanger will （）.