DIN 28139-2 E:2018-09 Welding necks for glass lined vessels - Part 2: Form M manhole, handhole and assembly opening for clamp screw connections - Connecting dimensions
2019DIN 28139-2:2019-05 Welding necks for glass lined vessels - Part 2: Form M manhole, handhole and assembly opening for clamp screw connections - Connecting dimensions
1970DIN 28139-2 E:2018-09 Welding necks for glass lined vessels - Part 2: Form M manhole, handhole and assembly opening for clamp screw connections - Connecting dimensions
1985DIN 28139-2:1985 Welding necks for glass lined vessels; form M manhole, handhole and assembly opening for clamp screw connections; connecting, dimensions