centrifugal pump is cheaper than reciprocating pump
the size of centrifugal pump with same capacity is smaller than that of reciprocating pump
centrifugal pump makes maintenance easier than reciprocating pump does
all of the above
第1题：
If a centrifugal pump is driven by a constant speed electric motor and produces a discharge pressure less than designed, the cause is probably ______.
A.excessive pump speed
B.excessive suction head
C.worn wearing rings
D.gross pump misalignment
第2题：
You start a centrifugal cargo pump to discharge cargo．The pump works for a while and then loses suction．This could be caused by ______．
A.The pump running backwards
B.Incomplete priming
C.The discharge head being too high
D.All of the above
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：
Single stage or multistage
High pressure or low pressure
Open or close coupled
Horizontal or vertical
第8题：
Modern ships are navigated by _ （卫星）.
A.moon
B.satellite
C.sextant
D.radar
第9题：
a centrifugal fan
a direct expansion cooler
a hermetic compressor
a centrifugal pump
第10题：
（1），（2）
（2），（3）
（1），（2），（3）
（2）only