17 Junctions not of metal for water pipes, junctions of plastic combined with metal for water pipes; pipe joints not of metal, pipe joints of plastic combined with metals; pipe couplings of plastic for metallic pipe connections; electric welding fittings of plastic combined with metal, for connecting pipes and conduits, accessories of plastic combined with metal, for electric welding fittings, namely, connecting saddles, tapping saddles and pressure tapping saddles, caps for pressure tapping saddles for sealing and insulation purposes; accessories for non-metal pipes, namely, junction sleeves and branch connectors of plastic, and insulating materials therefor; welding flanges, namely, plastic pipe fittings for welding polyethylene conduits, for gas, water and industrial purposes; pipe couplings and pipe reducing adapters of plastic; pipe junction fittings wholly or mainly of non-metallic materials for water and waste water conduits and gas pipes; plastic material in extruded form for use in the production of films, coating films, foils, sheeting, blocks and rods; non-metal pipes, tubes and piping, fastening, connecting and intermediate elements for non-metal piping; plastic composite materials in the form of profiles, boards, sheets, blocks, rods and pellets for use in manufacturing; sealings, namely, sealing and insulating materials; non-metal pipe couplings and joints, except for vehicles; packing and insulating materials; filling materials, namely, packing foam in sheet form; extruded plastic in the form of bars, blocks, pellets, rods, sheets and tubes for use in manufacturing; thermoplastic extruded profiles used to line and seal containers and pipes; seals, namely, non-metal seals for use in sealing and closing non-metal pipes; hoses, namely, non-metal hoses for plumbing use; electric insulators, namely, electrical ceramic insulators