"Cannot connect parts. Flanged connection failed.. No connection defined.. Auto Flange-Compound joint.." when connecting a flange to a pipe in AutoCAD Plant 3D

Autodesk Support

Mar 12, 2025

Products and versions covered

Issue:

When connecting a flange to a pipe, the flanges will not connect to each other and the following error prompts in AutoCAD Plant 3D:

"Plant 3D Piping Errors

One or more items have caused an error.
Cannot connect parts.
Flanged connection failed due to the properties mismatch.
(E1.NominalDiameter IN (15, 16, 20, 25, 32, 40, 50, 63, 65, 75, 80, 90, 100, 110, 125, 140, 150, 160, 180, 200, 
225, 250, 280, 300, 315, 350, 355, 400, 450, 500, 550, 560, 600, 630, 650, 700, 800, 900, 1000, 1200) AND
E2.NominalDiameter IN (15, 16, 20, 25, 32, 40, 50, 63, 65, 75, 80, 90, 100, 110, 125, 140, 150, 160, 180, 200, 
225, 250, 280, 300, 315, 350, 355, 400, 450, 500, 550, 560, 600, 630, 650, 700, 800, 900, 1000, 1200))
No connection defined for end types FL and SO in the config file. 
AutoFlange-Compound joint AutoFlange cannot connect with two simple joints."

Plant 3D Piping Errors when connecting flanges to pipe.

Another error occurred when moving the already connected pipe to a valve.

Environment:

  • Wrong end connections configured in Piping connection settings.
  • End Type mismatch.
  • Pressure class mismatch.
  • Components units mismatch.
  • Nominal Diameter mismatch.

Solution:

The error message indicates three different issues. To address them, perform one of the following steps:

AutoFlange connection failed due to the properties mismatch.

  • Adopt the flange properties in the spec
  1. Open Spec Editor and open the specific project spec.
  2. Double-click the green button of the specific flange in the spec.

Yellow triangle with a black exclamation mark. 

  1. Double-click this symbol,
  2. Select the specific size and reorder the priority of the spec flanges. Give the one flange with the specific end code the highest priority
  3. Check "Mark as resolved" for this size" and close the dialog box. 
  4. Save the spec.
  5. In AutoCAD Plant 3D, execute command PLANTSPECUPDATECHECK.

Remove the mandatory property in the compound joint

  1. Open Project Setup and switch to the node "Plant DWG Settings - Piping Connection Settings". 
  2. Select the compound joint "AutoFlange_<specific name>" and click "Modify". 
  3. In the new dialog box, deselect the property "Facing".
  4. Apply and close Project Setup.

No connection is defined for end types XX and XX in the config file.

  • A large joint connection offset tolerance in the project DefaultConnectorsConfig.xml can cause the autoconnecting behavior in Plant 3D to malfunction.
  • Set all joint Offset Tolerance values to 0 in the project DefaultConnectorsConfig.xml.
     

AutoFlange-Compound joint AutoFlange cannot connect with two simple joints.

  1. Copy an existing or create a flange with the same Nominal Diameter.
  2. Port 2 can be configured to allow connection to a pipe. Example: End Type: BV
  3. Add component to spec. 
  4. Increase component priorities through Part Use Priority. 
  5. Save changes.
  6. In AutoCAD Plant 3D, execute command PLANTSPECUPDATECHECK.

Products:

AutoCAD Plant 3D;

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