Filter Separators Filter Separators remove water, dirt and rust from your compressed air system. They prevent these contaminants from plugging or damaging the compressed air products. A filter separator should be installed prior to an oil removal filter, pressure regulator or valve. The Model 9003 Manual Drain Filter Separator has a polycarbonate bowl and a 20-micron filter element. A manual drain is used to empty the filter. Model 9002, 9004, and 9032 Automatic Drain Filter Separators have a metal bowl and a 5-micron filter element (Model 9004 has a polycarbonate bowl with a metal guard). An internal float automatically activates the drain when the bowl becomes full. Mounting Brackets are available for the Filter Separators. Coupling Kits for Filter Separator and Oil Removal Filter Combinations are also available.