a two - stage sealed magnetic filter continuously removes magnetic and non - magnetic contaminants from liquid process streams . elongated non - magnetic holder sleeves encasing magnet bars attract magnetic contaminants while a screen cylinder captures non - magnetic contaminants . the magnet bars are accessible without having to open the interior of the housing to the environment . thus , during maintenance , removing the magnet bars from the holder sleeves releases the magnetic contaminants that have adhered to the holder sleeves into the screen cylinder which partially encloses the holder sleeves . contaminants are flushed out of the magnetic filter without exposing workers to potentially hazardous substances . polymeric sludge occluded with iron compounds can be effectively removed from streams in refineries and chemical plants . the iron compounds are formed from carbon steel which is prevalent in plant machinery and that corrodes in the presence of acidic contaminants .