This European Standard collects and classifies the possible imperfections in welds made with pressure. A uniform designation is specified. Only the type, shape and dimensions of the different imperfections caused by welding with pressure are included. Metallurgical deviations are not taken into account. Imperfections produced other than by the welding operation, for example additional stresses, loads or environmental factors are not covered by this standard.Information concerning the consequences of the mentioned imperfections and the use of particular structures is not given because this depends on the specific requirements of the joint.