Abstract: A pump for Whirlpool and Spa applications has a series wound universal motor which is directly coupled to a centrifugal impeller for operation in the range of 4000 to 9000 RPM. Variable speed of the pump is easily accomplished with a universal motor by varying the voltage to the motor.

Abstract: A self-draining pump comprises a pump housing which bounds an impeller chamber having a central axis that is substantially horizontal in a position of use of the pump and an open end facing in one axial direction. An output passage of the pump housing communicates with a radially outward region of the impeller chamber. An impeller is received in the impeller chamber for rotation about the central axis for impelling fluid from a radially inward region toward the radially outward region of the impeller chamber.

Abstract: A diaphragm pump pumping arrangement includes two diaphragm pumps which are arranged and operate in tandem. Each of the diaphragm pumps includes a housing and a movable wall that includes a flexible diaphragm and subdivides the interior of the respective pump housing into a pumping chamber and an actuating chamber. An air distributing control arrangement interposed between and connected to the pump housings includes a spool valve movable in a bore of an aluminum casing of the control arrangement between two end positions in which it alternatingly achieves the admission of the compressed air into one, and discharge of the air from the other, actuating chamber.