A.increase discharge pressure
B.increase suction vacuum
C.develop pulsation flow
D.keep a steady rate of flow
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A.slack enough to allow slight leakage of fluid
B.slightly clocked
C.brought up tight so as not to allow any leakage
D.fitted with a relief valve
A.Volute pump
B.Diffuser pump
C.Regenerative pump
D.All of the above
A.mixed-flow
B.axial-flow
C.centrifugal
D.displacement
Which of the following operating features do displacement pumps bear if they are working under no-cavitation condition?()
(1) output is almost directly proportional to speed
(2) they are self-priming
(3) they will develop a discharged pressure equal to the resistance to be overcome, irrespective of speed
A.(1)and(2)
B.(2)and(3)
C.(1)and(3)
D.(1),(2)and(3)
Which of the following pumps will build up a bursting pressure or stall their motors if the discharge valves are closed?()
(1) gear
(2) centrifugal
(3) screw
A.(1)and(2)
B.(1),(2)and(3)
C.(1)and(3)
D.(2)and(3)
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