Abstract: An impeller for a centrifugal pump includes a radially inner hub, and a plurality of blades extending straight and along a direction that is perpendicular to a rotational axis of the impeller. The blades extend from a radially outer end to a radially inner end, and define a generally frusto-conical envelope. A flow control feature is formed between the radially inner end of the blades and the hub. The flow control feature has a curved upper surface.

Abstract: An impeller for a centrifugal pump includes a radially inner hub, and a plurality of blades extending straight and along a direction that is perpendicular to a rotational axis of the impeller. The blades extend from a radially outer end to a radially inner end, and define a generally frusto-conical envelope. A flow control feature is formed between the radially inner end of the blades and the hub. The flow control feature has a curved upper surface.

Abstract: An electromagnetic seal for a centrifugal pump controls movement of a valve member away from a normally closed position against a sealing surface at the entrance to a reservoir behind the expeller region of the pump, the valve member being controlled by a magnetizable clapper movable within a sealed enclosure toward and away from an electromagnetic coil which may be energized either by the drive motor of the pump or a self-contained generator in the pump driver assembly. Circulation of fluids between the impeller and expeller regions of the pump is enhanced by placement of vents in the impeller and a circumferential groove in the path of flow of fluid through the expeller to create increased turbulence and assist in flushing out foreign particles along with fluid in the expeller region when the pump is in operation. The effectiveness of this combination permits the employment of dry running secondary containment seals which do not require elaborate seal support systems.

Abstract: A centrifugal pump of the hydraulic sealing type has a novel and improved sealing apparatus for establishing a hydraulic seal and limiting the flow of liquid from a pump casing into a reservoir or seal housing at one end of the pump casing, and a valve assembly in the seal, housing has a valve member normally urged into engagement with the seal housing to isolate liquid in the seal housing from the casing by washer-like spring elements. When the pump is activated and brought up to speed, centrifugal force-responsive pivot members will impart sufficient opening pressure to overcome the resistance of the spring members when the pump approaches operating speed to move the valve member away from sealed engagement with the seal housing; and when the speed is reduced below the operating speed level the spring elements will rapidly undergo deflection to cause the valve member to return to a closed position.