increase speed
increase the size of the cardent assembly
reduce wearing ring clearances
change the pump to a close coupled arrangement
第1题：
It is possible to mount a double suction centrifugal pump impeller with the vanes facing in the wrong direction. This would cause the pump ______.
A.head capacity to improve
B.discharge to be reversed
C.efficiency to decrease
D.slippage to decrease
第2题：
Single stage or multistage
High pressure or low pressure
Open or close coupled
Horizontal or vertical
第3题：
Throttling in the _____ line of a centrifugal pump involves the risk of the pump cavitation.
A.suction
B.exhaust
C.pressure
D.discharge
第4题：
have a greater head capacity
operate with increased impeller efficiency
discharge through the suction side of the pump casing
require more power to run the shaft
第5题：
Oil is discharged from the impeller through the outlet
Gravity causes the oil to flow toward the discharge
The self-priming feature of the centrifugal pump enables it to draw its own suction as it starts
The discharge capacity varies directly with the speed of the impeller
第6题：
All of the following steps are taken in starting a centrifugal pump，EXCEPT to ______．
A.Set the relief valve
B.Check the lubrication system
C.Vent the pump casing
D.Open the pump suction and discharge valves
第7题：
the mechanical seal
packed stuffing boxes
either A or B
neither A nor B
第8题：
An increase in the fuel injection pump discharge pressure can be caused by a/an _______.
A.leaking delivery valve
B.excessive bearing end play
C.plugged injector spray hole
D.increased plunger stroke
第9题：
opening more bypass lines
opening additional expansion valves
adding refrigerant
speeding up the machine
第10题：
cavitation
water hammer
fluid friction
steam knock