Ships and marine technology – Graphical symbols for technical documentation – Part 2: Piping and hose assemblies, pipe and hose joints, penetrations; Text in German and English
standard by Deutsches Institut Fur Normung E.V. (German National Standard), 05/01/2017

Ships and marine technology – Graphical symbols for technical documentation – Part 2: Piping and hose assemblies, pipe and hose-joints, penetrations
standard by Deutsches Institut Fur Normung E.V. (German National Standard), 09/01/1999