Sewage/Effluent Pump

Overview

A sewage or effluent pump moves wastewater out of a basin where gravity drainage is not possible, for example a basement bathroom below the sewer line or a septic pump-up to a drain field. It runs fully submerged in the liquid it pumps, so its motor must be sealed against an aggressive, solids-laden flow. The impeller is built to pass solids that would jam an ordinary pump, and on grinder models a cutter shreds them first so the slurry can be pushed through smaller pipe at higher pressure.

The Submersible Motor is an oil-filled sealed unit with two shaft seals in tandem. It drives the Solids-Handling End end inside the Volute & Discharge, which routes flow to the discharge. A Float Switch starts the pump on level, the Power Cable brings power and the switch signal down to it, the Electrical set starts the motor, and the Lifting Handle is used to retrieve it.

How it works

When the basin fills, the Float rises and trips its switch, energizing the motor through a Relay. The motor spins the Solids Impeller, a recessed vortex or grinder design that throws the solids-laden liquid into the Volute Casing and up the Discharge Fitting. On grinder models a Cutter Ring shears solids against the impeller first, turning rags and waste into a fine slurry that can be forced through narrow pressure pipe. The Wear Plate sets the running clearance and absorbs the abrasive wear from grit.

Sealing is what lets the pump survive submerged. The motor and the Seal Chamber are filled with Seal Oil dielectric oil, and two seals run in series: the lower Oil Seal faces the sewage while the Upper Seal backs it up, with the oil chamber between them buffering any seepage before it can reach the windings. The Power Cable enters through a potted Cable Seal so water cannot track in along the conductors, and the Ball Bearing pair carries the shaft inside the dry, oil-filled cavity.