Non-metallic pipes, tubes, conduits, valves, drain traps not of metal or plastic, pipe strainers, channels, channel covers, drain gullies including non-metallic drainage pipes, and sieves being parts of drains; parts, fittings and accessories for the foregoing, including pipe, valves, strainers or threaded fittings, and any of the foregoing sold together with pipe systems as a kit; all the foregoing being non-metallic goods