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单选题
An increase in rotor clearances in a rotary pump will （）.
A
increase discharge pressure
B
decrease pump capacity
C
decrease pump cavitation
D
decrease reaction ring clearance
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noise and vibrationB
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考题
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connection must guide the liquid to the lantern ringsD
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单选题When a hydraulic vane pump is working, which of the following is in contact with the vanes?（） (1) the rotor (2) the internal surface of the housing (3) the external surface of the housingA
(1) onlyB
(2) onlyC
(1) and (2)D
(1), (2) and (3)
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leaking delivery valveB
excessive bearing end playC
plugged injector spray holeD
increased plunger stroke
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（1）B
（1）and（2）C
（2）D
neither（1）nor（2）
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(1) onlyB
(2) onlyC
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单选题Why are removable sleeves installed on centrifugal pump shafts?（）A
They make it easier to replace the pump shaft packingB
They can be economically replaced as they wear outC
They can be removed when it is necessary to lighten the weight of the pumpD
They increase the strength of the shaft
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