RWO Maschinenfabrik is founded at Gutenbergstraße 6, 2803 Weyhe-Dreye. RWO stands for the founders’ family names Riewer, Werle and Otto.
The Otto family had operated a bell foundry in Bremen Hemelingen since 1873. The roots of the first oily water separators go back to the companies Heinz Gaster Ingenieur GmbH and Otto Schiffsarmaturen und Apparatebau GmbH.
More than 1000 OWS-GSF (Gravity Separator Filtration) separators were sold.