17 Flexible pipes, tubes, hoses, and fittings therefore, including valves, non-metallic; fittings of plastics for liquids, for gas and for compressed air lines for connecting hoses or pipes together and for connecting hoses or pipes to apparatus or machines; couplings of plastics for hoses, couplings of plastics for hoses for pressure lines; pipes made of plastics and not for building purposes, connecting pieces for pipes and hoses, pipe branch pieces, pipe couplings, pipe muffs, pipe clamps, joint pieces for pipes, clips of rubber for connecting pieces of pipes, rubber stoppers for pipelines, seals for pipes, for pipe connections, for pipe fittings, pipes sealant tape, rings of rubber for use as pipe spacers, rings of rubber for use as pipe connection seals, pipe sealant compounds for preventing rustings, casings of rubber for pipes, protection sleeves of rubber for pipes, pipelining, pipelining for sealing pipes, filtering materials as semi-processed foams or films of plastic, adaptors for pipes, not of metal, connecting flanges for pipes, cast parts of plastic for pipes and stop valves, elbow joints of plastic, all the aforesaid goods not being of metal; pipe couplings; pipe sealants; non-metallic pipe couplings; gaskets for pipe joints; pipe fittings, non-metallic; pipe coupling parts, non-metallic; pipe screwing pieces, non-metallic; rubber rings for sealing pipe connections; pipe fittings, non-metallic, for flexible compressed air pipes; hoses; hose conduits; hoses made of rubber; flexible hoses made of plastics; hose couplings, non-metallic; hose connections, non-metallic; screwing pieces, non-metallic; sealing rings for hose fittings, non-metallic; sealing kits for valves; seals for pipes; valves, not of metal, for pipes and hoses; hose nozzles, non-metallic