Autocad - Plant 3d Iso Symbol Skey

In AutoCAD Plant 3D, the (Symbol Key) is a four-character code that determines which graphical block is used to represent a 3D component on an automatically generated isometric drawing. Core Components of ISO Symbol Mapping

The system relies on three primary elements to correctly display a symbol: : Defines the component's category (e.g.,

). This dictates how the component behaves and its placement in the bill of materials (BOM). : A specific code (e.g., ) that maps the component to an AutoCAD block. First two letters : Identify the component class (e.g., for Flange, for Elbow). Last two letters : Identify the specific sub-type or end connection (e.g., for Slip-On, for Butt Weld). Content ISO Symbol Definition

: The property where these are combined, formatted exactly as TYPE=VALVE,SKEY=VBBW (no spaces after the comma). Key Files for Customization All mapping and block data are stored within your project's IsoSkeyAcadBlockMap.xml : The "translator" file. It contains lines like , linking the SKEY to a specific block name. IsoSymbolStyles.dwg

: The block library. All isometric symbols are stored here as AutoCAD dynamic blocks. Step-by-Step Configuration Guide To add or modify a custom symbol, follow this workflow:

3. Copying Symbols Between Projects

Never redraw. Use the ISO Symbol Editor -> Export / Import functionality. autocad plant 3d iso symbol skey

• Export IsoSymbols.dwg from Project A (as a DXF).
• Import it into Project B.

Conclusion: SKEYs are the Rosetta Stone of Isometrics

The AutoCAD Plant 3D iso symbol skey is not just a technical setting; it is the translation layer between your intelligent 3D model and the 2D drawing that a pipefitter uses to weld spools together.

By mastering SKEYs, you move from being a casual user to a Plant 3D Administrator. You can enforce company standards, satisfy client-specific drafting requirements, and eliminate the manual cleanup of isometric drawings.

Action Items for Mastery:

1. Open your project’s IsoSymbols.dwg today and browse the cells.
2. Identify one part that currently looks wrong on your ISOs.
3. Change its SKEY via the Spec Editor.
4. Try creating one custom symbol (e.g., a custom air release valve) and assign it a unique SKEY.

The power is in the mapping. Control the SKEY, and you control the ISO.

Advanced Techniques: Using Wildcards and Long SKEYs

Modern versions of Plant 3D support Long SKEYs (more than 3 characters). This allows for intelligent matching. In AutoCAD Plant 3D, the (Symbol Key) is

For example, instead of one GAV symbol for all gate valves, you can have:

• GATE-150LB → Block G15
• GATE-300LB → Block G30

To do this, you do not change the SKEY property in the spec. Instead, use the SkeyMap XML to map the FullDescription or LongSkey:

<SkeyMap skey="GATE-150LB-FLANGE" acadBlock="G15" />
<SkeyMap skey="GATE-300LB-FLANGE" acadBlock="G30" />

Then, in your IsoSymbols.dwg, create blocks named G15 and G30 with different sizes (thicker flanges, different bolt patterns).

Part 1: What is an SKEY (Symbol Key) in Plant 3D?

Before we modify anything, we must understand the hierarchy of how AutoCAD Plant 3D draws an isometric.

When you place a component in the 3D model (e.g., a gate valve), the part has several properties: Export IsoSymbols

• Part Description: "Gate Valve, Flanged, 150LB"
• Short Description (ShortDesc): "GATE VALVE"
• Part Family: "Valves"
• The SKEY: "GV" (Typically)

When you run the IsoConfig and generate the drawing, the Plant 3D ISO engine reads the SKEY from the model. It then looks at the IsoSymbols.dwg file (or your project’s symbol map) and finds the block named GV. It then inserts that block (the 2D representation) onto the isometric line.

In short: The SKEY is the lookup key that tells the ISO engine which 2D block to draw.

4. Audit Your SKEYs

Use the Plant3D command: PlantIsoSymbolAudit. This scans your entire model and reports which parts have missing SKEYs before you generate 100 isometric drawings.

The Default Logic

3D Part Property (SKEY) -> ISO Symbol Map -> 2D Block in IsoSymbols.dwg

If the SKEY is missing or does not match a block in the symbol library, the ISO engine draws a default box or an "unknown" symbol (usually a question mark or a blank circle).

How to Customize an AutoCAD Plant 3D ISO Symbol SKEY (Step-by-Step)

Let’s walk through a real-world example: You need a custom "Gear Operated Gate Valve" symbol that looks different from the standard handwheel valve.

Example Entry (Custom / Override):

<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>

Pro Rule: Never edit the original IsoConfig.xml in the installation folder. Always place a modified copy in your Project Isometric folder. Plant 3D uses a cascading override logic: Project > System.