A maker of hydraulic oil cleaning systems has introduced its smallest unit yet, aimed at machines with less than 150 gal of oil. Kleentek in Cincinnati brought out the model DOC-R3, which weighs only 43 lb. Like other Kleentek systems, it uses electrostatic attraction to remove insoluble, oxidized components that cause tar, varnish, or sludge. These are removed regardless of particle size, unlike mechanical filters, without affecting soluble oil additives. Kleentek’s next largest unit filters up to 1050 gal of oil.