DIN 21057-12:2017 制炼厂的管道等级. 第12部分: 使用1.2和5.1组材料具有高温下特定性能的非合金和合金钢管组件的交货技术条件
Pipe classes for process plants - Part 12: Technical delivery conditions for pipe components of non alloyed and alloyed steel with specified properties at elevated temperatures of material group 1.2 and 5.1