17 MOLDED OR EXTRUDED SEMI-FINISHED PRODUCTS MADE OF SYNTHETIC RESINS, NAMELY, SHEETS, RODS, BANDS, TUBES, PIPES, ELBOWS, COUPLINGS, JOINTS, GASKETS, ELBOWS, TEES, FLANGES, SPACERS, CROSSES, BRANCHES, WEDGES, INSTRUMENTATION PLUGS, BELLOWS AND EXPANSION EQUALIZERS, PLUNGERS, AND COLLARS; SYNTHETIC RESIN FOR COATING MECHANICAL PARTS AND LABORATORY AND INDUSTRIAL EQUIPMENT; AND SYNTHETIC RESIN SEALING PARTS-NAMELY, JOINTS, BANDS, TAPES FOR THREADINGS, FILMS, WICKS, FABRICS, WASHERS, RINGS, PACKINGS AND LININGS