> For the complete documentation index, see [llms.txt](https://help.auxalia.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://help.auxalia.com/plant-tools/plantspecdriven/how-to-use/configuration/pid-classes-symbols.md).

# P\&ID Classes & Symbols

This chapter explains which classes you may want to create and what to consider in regards to symbols (e.g. Flanges, Tees). We also suggest Default Values for the PSD\_Key property used for filtering the Parts from the Pipe Spec.

We also created a drawing which contains the flange and tee symbols for the various standard used by Plant 3D and which are use for the [Test Projects](/plant-tools/plantspecdriven/how-to-use/test-projects.md).

![](/files/XBLEEc7BgTw1lDJ2WRAb)

Table of Content:

* [Hand Valves Class](/plant-tools/plantspecdriven/how-to-use/configuration/pid-classes-symbols/hand-valves-class.md)
* [Piping Fittings Class](/plant-tools/plantspecdriven/how-to-use/configuration/pid-classes-symbols/piping-fittings-class.md)
* [Flange Class](/plant-tools/plantspecdriven/how-to-use/configuration/pid-classes-symbols/flange-class.md)
* [Fasteners Class](/plant-tools/plantspecdriven/how-to-use/configuration/pid-classes-symbols/fasteners-class.md)
* [Tees Class](/plant-tools/plantspecdriven/how-to-use/configuration/pid-classes-symbols/tees-class.md)
* [PSD\_Key Suggestion](/plant-tools/plantspecdriven/how-to-use/configuration/pid-classes-symbols/psd-key-suggestion.md)