In AutoCAD Plant 3D, the combination of ISO Symbol Type and SKEY (Symbol Key) is the engine that converts 3D piping models into accurate isometric drawings. Without a valid SKEY, the software cannot identify which symbol to place, often resulting in fragmented or split isometric outputs. Core Concepts
<SymbolDef>
<Name>My Custom Diaphragm Valve</Name>
<Skey>DIA_CUST</Skey>
<BlockName>Diaphragm_Custom_Top</BlockName>
<Annotation>SPECIALTY</Annotation>
<Overrides>
<Scale>1.5</Scale> <!-- Scale symbol by 150% -->
</Overrides>
</SymbolDef>
You have three levels of control:
Tips and Best Practices
Now, every time you run isometrics, your custom symbol appears automatically. autocad plant 3d iso symbol skey
In this example, the skey file defines a valve symbol with a circular shape, a diameter of 20 units, and a red fill color. The symbol also has a label "VALVE" with a font size of 12. In AutoCAD Plant 3D , the combination of
If Step 4 fails (No Match): The component is drawn as a simple box or line, and a warning is logged in Isogen.log. How to Find and Change an SKEY You
Each symbol is drawn using specific rules: