Internal gear pump Model GP81E-1U22B GP: General Purpose, mono block pump in cast iron 81: Pump size DN 80-3" E: Suction/Discharge connection in-line 1: Casing & cover: GG-25, Rotor/Idler: GG-25, Shaft: St.60.2 U: Idler bearing and main bearing lubricated by pump medium 2: Bearing: Idler bush: Bronze, idler pin: Hardened 16 MnCr5 2: Bearing bush: Bronze, Shaft: St.60.2 B: Shaft seal: Teflon-impregnated, non-asbestos packing.