(under subclass 45) Subject matter comprising a protective cover or layer which may be inside the coupling or outside it.
SEE OR SEARCH THIS CLASS, SUBCLASS:
47+, for insulated couplings.
222.1+, for a coupling for a plural layer pipe, which provide distinct connections for two or more layers.
SEE OR SEARCH CLASS
137, Fluid Handling,
375, for similar structure combined with flow control means. 138, Pipes and Tubular Conduits,
124+, for lined or covered flexible fabric pipe; subclass 131 for flexible pipe having a spirally wound liner; subclasses 137+ for other lined or covered flexible pipe; and subclasses 140+ for other lined or covered pipe.
156, Adhesive Bonding and Miscellaneous Chemical Manufacture, appropriate subclasses for methods of making heat insulating covers.
220, Receptacles,
23.9, 62.21, 495.01+, 574.3, and 908.1+ for receptacle linings.
