Internal gear pump Model PD51EMR-4U222 PD: Petrochemical duty pump in carbon steel, Complete with motor on a common baseplate through flexible coupling 50: Pump size DN 50 - 2 " E: Suction/Discharge connection in-line M: Sealing with single mechanical shaft seal combined with a product lubricated sleeve bearing as main bearing R: Safety valve, single acting for protection against excess pressure 4: Casing & cover: GS-52.3, Rotor/Idler: GG-25, Shaft: St.60.2 U: Idler bearing and main bearing lubricated by pump medium 2: Idler bush: Bronze, idler pin: Hardened 16 MnCr5 2: Bearing bush: Bronze, Shaft: St.60.2 2: Shaft seal: Single mechanical shaft seal, O-ring type