(under subclass 22) Closed vessels combined with a heat-producing means.
SEE OR SEARCH CLASS
122, Liquid Heaters and Vaporizers, appropriate subclasses for boilers.
126, Stoves and Furnaces,
344+, for water heaters for domestic or cooking purposes.
422, Chemical Apparatus and Process Disinfecting, Deodorizing, Preserving, or Sterilizing, 129.1, for similar apparatus used in the production of soaps.
