Moyno Progressing Cavity Pump. Model: 2L8. S/N: A-8034-2. Type: SSR. Capacity: approx. 40 gpm. The Moyno progressing cavity pump is a single screw rotary pump. The pumping action is created by the single helical rotor rolling eccentrically in the double threaded helix of the stator. Robbins & Myers Motor. Mounted on steel base. Inlets/outlets: (1) 3 in. dia. ports. Overall dimensions: 74 in. L x 46 in. W x 24 in. H.