DIN 1912-2 SUPP 1 : 1977被替代
GRAPHICAL REPRESENTATION OF WELDS, SOLDERING AND BRAZING JOINTS - WELDING POSITIONS, SLOPE, ROTATION, DIRECTIVES OF WELDING POSITIONS ON THE PIPE (EXAMPLES)
出版：German Institute for Standardisation (Deutsches Institut für Normung)
专家解读视频
