17 Flexible pipes, tubes, hoses, valves, and fittings therefor and fittings for rigid pipes, all non-metallic; Non-metallic couplings for pipes; Non-metal hose fittings, namely, hose bandage; Non-metallic pipe extensions; Non-metal pipe couplings and joints; Insulation jackets for industrial pipes; Casings of rubber for tubes; Pipe muffs, not of metal; Fittings, not of metal, for rigid pipes; Non-metallic couplings for flexible pipes; Pipes made of rubber; Rubber tubes and pipes; Flexible hoses, not of metal; Flexible plumbing pipes of plastic; Non-metallic seals for gas pipes; Non-metallic seals for preventing leakage of gases; Flexible plastic pipes for conveying natural gas; Non-metallic flexible tubes for the conducting of gases