ISO 14084-2:2015 specifies graphical symbols for process diagrams for power plants and guidelines for creation of new graphical symbol examples.
ISO 14084-2:2015 is a collective application standard of the ISO 14617-series.
Graphical symbols for fluid power diagrams can be found in ISO 1219-1.
Graphical symbols for electrotechnical diagrams can be found in IEC 60617.