(under subclass 179) Processes wherein the used oil is purified by distillation or a mechanical removal of gaseous material as by heating or use of reduced pressure.
SEE OR SEARCH THIS CLASS, SUBCLASS:
347+, for processes of distilling mineral oils.
SEE OR SEARCH CLASS
202, Distillation: Apparatus, appropriate subclass for apparatus for distillation not otherwise provided for.
203, Distillation: Processes, Separatory, appropriate subclass, for a process of separatory distillation not otherwise provided for. 516, Colloid Systems and Wetting Agents; Subcombinations Thereof; Processes of Making, Stabilizing, Breaking, or Inhibiting,
113+, for compositions for or subcombination compositions for or breaking of or inhibiting of colloid systems (e.g., foam breaking, emulsion breaking, dispersion inhibiting, suspension settling, gel breaking, smoke suppressing, coagulating, flocculating), when generically claimed or when there is no hierarchically superior provision in the USPC for the specifically claimed art. Combinations of emulsion breaking and a treatment of the mineral oil provided for in Class 208 are classified in Class 208.