This European Standard provides quality levels for imperfections in thermoplastics welded joints. It applies to material thickness above 2,0 mm. Three quality levels are given in order to permit application for a wide range of welded fabrication. They are designated by symbols B, C and D, where B is the most stringent. The quality levels refer to production quality and not to the fitness-for-purpose (see 3.2) of the manufactured product. This European Standard applies to the following thermoplastic materials: Table 1 Abbreviation Material description ABS Acrylonitrile-butadiene-styrene plastic ECTFE Ethylene-chlorotrifluoroethylene copolymer FEP Fluorinated ethylene propylene PB Polybutylene PE Polyethylene PFA Perfluoroalkoxy PP-B Polypropylene block copolymer PP-H Polypropylene homopolymer PP-R Polypropylene random copolymer PVC-C Chlorinated polyvinyl chloride PVC-U Unplasticised polyvinyl chloride (rigid PVC) PVDF Polyvinylidene fluoride and to the following welding processes: - Heated tool welding; - Electrofusion welding; - Hot gas welding using filler rod only; - Extrusion welding; - Solvent welding of pipes.