This standard specifies the method of testing the knowledge and skill of a welder who is required to carry out welds on thermoplastics in new constructions and repair work. The skill examination of a welder is an essential condition for the assurance of the quality of the welding work. The application of this standard guarantees that the examination is carried out according to a uniform test procedure. The standard applies when the contractor or the authorities responsible for the application require it. Gas and water utility network industries with alternative qualification programmes are excluded from this standard. This standard applies to the following welding processes: - hot gas welding: round nozzle, high speed nozzle, wedge; - extrusion welding; - heated tool welding: butt, saddle, socket, wedge; - electrofusion welding: socket, saddle. This standard applies to the welding of the following products: - sheet; - pipe; - fittings; - lining membrane. This standard covers the welding of the following groups of materials: - for sheets, pipes and fittings: - group 1: PVC (it includes all kinds of PVC-U and ABS and PC); - group 2: PP (it includes all kinds of PP); - group 3: PE (it includes all kinds of PE, PB); - group 4: PVDF;. group 5: ECTFE or PFA or FEP. - for lining membranes: - group 6: PVC-P; - group 7: PE (it includes all kinds of PE); - group 8: ECB.