Abstract: A sewage pump includes an injection molded thermoplastic upper housing that surrounds an electric motor and its cast iron motor support, except for the bottom wall of the motor support which forms one wall of a vortex volute, the remainder of the volute being constructed of injection molded thermoplastic. The volute includes an inlet aperture through the bottom, and integrally molded legs extending downwardly whose length is related to the diameter of the inlet aperture such that the clearance underneath the volute is less than the diameter of the solids that will pass through the inlet aperture. This prevents oversized solids from reaching the inlet aperture. The outlet of the volute terminates in an annular thermoplastic threaded connection that is threaded on both the interior and exterior for fitting to different sized effluent pipes.

Abstract: A sewage pump includes an injection molded thermoplastic upper housing that surrounds an electric motor and its cast iron motor support, except for the bottom wall of the motor support which forms one wall of a vortex volute, the remainder of the volute being constructed of injection molded thermoplastic. The volute includes an inlet aperture through the bottom, and integrally molded legs extending downwardly whose length is related to the diameter of the inlet aperture such that the clearance underneath the volute is less than the diameter of the solids that will pass through the inlet aperture. This prevents oversized solids from reaching the inlet aperture. The outlet of the volute terminates in an annular thermoplastic threaded connection that is threaded on both the interior and exterior for fitting to different size effluent pipes.