(under subclass 235) Devices involving the structure of headers for water tube boilers; also includes the coupling connection between the headers and water tubes and the closures for the hand holes in the headers when the form of the header is involved in the claims.
SEE OR SEARCH THIS CLASS, SUBCLASS:
511, for boiler tubes, flues and connections not provided for elsewhere.
SEE OR SEARCH CLASS
138, Pipes and Tubular Conduits, for structure of boiler tubes, per se, particularly
95, for return bend closures. 220, Receptacles,
200+, for manholes and closures of general application, whether applied to a boiler or boiler header, where the structure of the boiler or header is not involved.
285, Pipe Joints or Couplings,
189+, for couplings and unions between a tube and plate of general application.
