Abstract: A self-priming centrifugal pump has enhanced efficiency and performance characteristics and/or features which facilitate installation, inspection and maintenance of the pump. For efficiency and performance, the pump may include a smooth fluid flow path which enhances pump output for a given input power, including one or more of a specially shaped and directed volute discharge, a lack of internal stiffening ribs on the pump casing walls, a necked inlet and a rounded, flow-channeling outlet aperture. For maintenance and serviceability, the pump may include one or more of a coarse-threaded drive shaft and impeller with a concentricity feature, a combination port for both filling the casing and accessing the inlet flapper valve, and a drive disassembly system which facilitates attachment or removal of the drive system from the pump.

Abstract: A priming vacuum control system for use on a self-priming pump includes a priming vacuum control valve and a priming vacuum control valve-actuating system. The priming vacuum control valve is disposed between a vacuum pump and a priming chamber for the self-priming pump so as to decouple the vacuum communication between the vacuum pump and the priming chamber when the priming vacuum control valve is closed. In one illustrative embodiment, the priming vacuum control valve includes: a valve stem positioned within a valve body, and a valve spring or other means for biasing is operatively positioned between the valve body and the valve stem so as to apply a default closing force between the valve body and the valve stem. The “guideless” priming vacuum control valve of the present invention eliminates the inherent problems of sticking, poor performance and high maintenance exhibited by the prior state of the art priming vacuum control valves containing guides.

Abstract: A priming vacuum control system for use on a self-priming pump includes a priming vacuum control valve and a priming vacuum control valve-actuating system. The priming vacuum control valve is disposed between a vacuum pump and a priming chamber for the self-priming pump so as to decouple the vacuum communication between the vacuum pump and the priming chamber when the priming vacuum control valve is closed. In one illustrative embodiment, the priming vacuum control valve includes: a valve stem positioned within a valve body, and a valve spring or other means for biasing is operatively positioned between the valve body and the valve stem so as to apply a default closing force between the valve body and the valve stem. The “guideless” priming vacuum control valve of the present invention eliminates the inherent problems of sticking, poor performance and high maintenance exhibited by the prior state of the art priming vacuum control valves containing guides.