When consulting engineers’ and facility operators begin to plan an upgrade for their sewage treatment plants most are considering four primary pumps: Plunger pump technology, rotary lobe pumps, progressive cavity and double disc pumps.
A New Direction in Plunger Pumps: Sludge Pumping Capabilities With A Cleaner Design

How a Double Disc Pump Works

We have all seen the outside of a double disc pump but rarely do we see what makes the pump actually work. Just to review, a double disc pump is a positive displacement pump that uses a trunnion (elastomer), a disc and a connecting rod to force sewage from the suction side to the discharge side of the pump by creating a vacuum inside the pump body. The valve chambers with the black check valves you see in the photo help to manage higher than normal concentrations of grit and solids in municipal wastewater.
