A.injector
B.positive displacement
C.centrifugal
D.centripetal
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A.injector pumps
B.positive displacement pumps
C.centrifugal pump
D.centripetal pumps
A.the mechanical seal
B.packed stuffing boxes
C.either A or B
D.neither A nor B
As for a hydraulic vane pump, which of the following is in contact with the vanes during working: （）
(1)the rotor
(2)the pump shaft
(3)the external surface of the housing
A.(1) only
B.(2) only
C.(1) and (2)
D.(1),(2)and(3)
A.circular
B.elliptical
C.rectangular
D.hexagon
A.suction
B.exhaust
C.pressure
D.discharge
最新試題
If the relief valve on the discharge side of a hydraulic pump lifts, the cause could be （）.
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Pitting in the suction areas of a centrifugal pump bronze impeller is usually caused by （）.
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Which of the following statements is correct concerning heat transfer?（）
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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 （）.
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