(under the class definition) Apparatus comprising a pump* in which the working fluid* initially enters the casing* at the periphery and is discharged through a central opening in an axial direction, the runner* forcing the working fluid towards the center of the axis of rotation.
(1) Note. In order for a multistage pump* to be included under this definition the working fluid* must, in at least one stage, enter the periphery of the runner* and leave at or near the center.
