单项选择题
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
The amount of fluid delivered by a reciprocating pump c...
单项选择题The amount of fluid delivered by a reciprocating pump can be regulated by （）.
A.throttling the pressure line B.changing the speed of the piston C.either A or B D.None of the above is tree
The amount of fluid delivered by a centrifugal pump can...
单项选择题The amount of fluid delivered by a centrifugal 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
