Commonly used P&ID symbols (Piping and Instrumentation Diagram symbols) for instrument signals. Note that they may differ slightly from one project to another.
Process Connection | ![]() |
Electric signal | ![]() |
Capillary connection | ![]() |
Software signal | ![]() |
Mechanical link | ![]() |
Hydraulic signal | ![]() |
Pneumatic signal | ![]() |
Electric binary signal | ![]() |
Pneumatic binary signal | ![]() |