Appendix
Hydraulic and pneumatic symbols
Like electrical circuit diagrams, graphical representations of hydraulic and pneumatic systems are a shorthand way of representing the operation of a circuit by using standard graphical symbols. Although the diagrams show the relationship between components they are not a piping diagram.
Hydraulics and pneumatics use the same general symbols, the difference being that energy triangles, found on pumps and motors for example, are filled black on hydraulic diagrams and left clear on pneumatic diagrams.
The symbols listed below are generally in accordance with ISO 1219, although manufacturers do tend to use variations on this theme.