The polypropylene material in the OWS Series of Clean Pro oil water separators has the perfect effect on oil-it attracts oil and captures it, almost as if it draws oil like a magnet. That simplicity and our technology are at the root of the FS CURTIS OWS Series Clean Pro oil water separators efficiency to clean virtually all types of condensate, emulsified or not.The typical output oil residue value is less than 10 ppm.