Commonly used P&ID symbols (Piping and Instrumentation Diagram symbols) for piping fittings. Note that they may differ slightly from one project to another.
| Flange set |  |
| Blind Flange |  |
| Flow orifice |  |
| Removable pipe spool |  |
| Tee type strainer |  |
| Y type strainer |  |
| Basket type strainer |  |
| 2 basket type strainer |  |
| End plug |  |
| End cap |  |
| Reducer / Expander |  |
| Hose connection |  |
| Open spacer |  |
| Closed spacer |  |
| Open spectacle blind |  |
| Closed spectacle blind |  |
| Mixing Tee |  |
| Sight glass |  |
| Breather |  |
| Gooseneck vent |  |
| Sample cooler |  |
