DIN 28136-2
DIN 28136-2 Agitator vessels - Part 2: Positions and sizes of cover nozzles in non-alloy and stainless steel vessels
standard by Deutsches Institut Fur Normung E.V. (German National Standard), 12/01/2005
standard by Deutsches Institut Fur Normung E.V. (German National Standard), 12/01/2005