Plastic substances, semi-processed; plastics in extruded form for use in manufacture; fiber-reinforced plastics, not for textile use; glass-fiber fabrics for casings for pipes and fiberglass being fabrics for insulation; flexible pipes, not of metal; light-curing synthetic fiberglass tubes for insulation; lining tubes for the renovation of tube sections, consisting of fiberglass impregnated with artificial resin for insulation