Abstract: A low-cost, mass-produced oil purifier of plastic, utilizing reverse internal currents to remove impurities, has a sealed housing with upper and lower parts that interfit. The lower housing part has a circular base and a central, upright standpipe open at top and bottom, that is provided with exterior ledges at different levels on which perforated discs are supported. The upper housing part comprises an inverted shell fitted to the base of the lower part, and having an inverted cup depending from its top wall and surrounding the top of the standpipe. At one side of the inverted cup is an oil inlet on the upper housing part. The top perforated disk imparts a swirl to the incoming oil, which passes downward through the disks to a settling chamber at the bottom, and then in a purified state upward through the disks again to the open top of the standpipe, thence down through the standpipe and out at the bottom of the latter.