【单选题】In order to properly remove air from the casing of a centrifugal pump when starting, the pump should have a _____.
D.
vent valve attached to the casing at the top of the volute
【判断题】Centrifugal p umps or compressors are devices that converts mechanical energy to kinetic energy.
【简答题】A. p o tato B. p o lice C. p o pulation D. p o lite
【单选题】Which pump must always be primed ________.