> 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/use-cases/editing-line-segment-properties-pid/inserting-symbols-pid/understanding-assigning-pipe-spec-data-pid/changing-key-property-in-symbol-pid.md).

# Changing Key Property in Symbol (P\&ID)

This chapter describes how changing the Key property triggers the assigning of pipe spec data.

Typically you would set the Key values in Project Setup (see [PSD\_Key Suggestion](/plant-tools/plantspecdriven/how-to-use/configuration/pid-classes-symbols/psd-key-suggestion.md)).

If you insert a check valve you can see the Key value. Based on this property and the size PlantSpecDriven filters the pipe spec for suitable parts.

![](/files/b8PKr0V1rzot67IKBduL)

If you insert a ball valve you will see a different Key.

![](/files/9gxuBoU1P17N1u1vnmsK)

If you insert a general valve symbol you see that the Key shows just **V-**. The Key behaves like a wildcard. In this case the Part Selection dialog shows all parts which start with V-.

![](/files/pR1BGJNA6bQ0ItnWDiWj)

If you overwrite the Key for example with **V-Globe** ...

![](/files/loHvvsDxdAO7NPgiurF8)

...the Part Selection dialog will show only the globe valves.

![](/files/iYxlxGT59l12z5gfweOZ)

As always, after selecting a part of the dialog you see the assigned data.

![](/files/ukXIU2X8fvoASeEu8380)

You can also enter multiple Keys separated by a comma.

![](/files/b9WS0FaRSuitOmhrpec4)

Now you see the ball and globe valve parts.

![](/files/s0xsCIjsqJZpuykIadqT)

If you type in **V-Check**...

![](/files/RM6mMqjHbUvkTpcw7xz4)

...no Part Selection dialog will appear, because there is just one check valve in the pipe spec for size 100.

![](/files/zuAfkqPxH6bjYhHGUA5f)