Refrigerating systems and heat pumps - System flow diagrams and piping and instrument diagrams - Layout and symbols; German version EN 1861:1998— 35 стр.
Technical drawings - Simplified representation of pipelines - Terminal features of ventilation and drainage systems; identical with ISO 6412-3:1993— 5 стр.
Technical drawings - General principles of presentation - Part 20: Basic conventions for lines (ISO 128-20:1996); German version EN ISO 128-20:2001— 14 стр.