单项选择题
A.draw the liquid in；force the liquid out B.force the liquid out；draw the liquid in C.suction；draw D.deliver；outlet
The amount of fluid delivered by a helical pump can be ...
单项选择题The amount of fluid delivered by a helical pump can be regulated by （）.
A.throttling the pressure line B.changing the speed of the rotor C.either A or B D.None of the above is tree
Which of the following pumps are self-priming, and can ...
Which of the following pumps are self-priming, and can deal with liquid from a level below the pump? （） (1) reciprocating (2) rotary (3) centrifugal
A.(1)only B.(1)and (2) C.(1),(2)and(3) D.(2)and(3)
The amount of fluid delivered by a positive displacemen...
单项选择题The amount of fluid delivered by a positive displacement pump can be regulated by （）.
A.throttling the pressure line B.changing the speed of the driving rotor C.either A or B D.None of the above is tree
