This Standard specifies graphical symbols for valves and dampers in diagrams, including symbols forgeneral-purpose valves, those used in fluid power systems and hygienic valves used in the food andpharmaceutical industries.
ASME Y14.40.8-2002 history
2002ASME Y14.40.8-2002 Graphical Symbols for Diagrams, Part 8: Valves and Dampers