"Cannot connect parts" when trying to insert a flange onto a pipe in AutoCAD Plant 3D

Autodesk Support

Feb 19, 2025

Products and versions covered

Issue:

When trying to insert a flange onto a pipe in AutoCAD Plant 3D, an error message pops up and the inserted flange stays unconnected, and no second flange is inserted automatically. The following prompts may be displayed:

  • AutoFlange connection failed due to the properties mismatch.

Plant 3D Piping Errors

One or more items have caused an error.
Cannot connect parts.
AutoFlange connection failed due to the properties mismatch.
E1.Facing= '<specific end code>"
Plant 3D Piping Errors screenshot

  • AutoFlange-Compound joint AutoFlange cannot connect with two simple joints.
    Cannot find Gasket in the <spec name> spec.

Plant 3D Piping Errors
 

One or more items have caused an error.
Cannot connect parts.
Cannot resolve Flanged connection.
Cannot find Gasket in the <spec name> spec.

NominalDiameter='2in' AND Facing='RF' AND PressureClass='300'
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 screenshot

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

Plant 3D Piping Errors
 

One or more items have caused an error.
Cannot connect parts.
Flanged
NominalDiameter=E1.NominalDiameter AND IsLugSet=0 AND ((Facing=E1. Facing OR Facing=E2.Facing) AND PressureClass=E1.PressureClass, pos = 63, err = eQryErSynUnbalPar
NominalDiameter=E1.NominalDiameter AND IsLugSet=0 AND ((Facing=E1. Facing OR Facing=E2.Facing) AND PressureClass=E1.PressureClass, pos = 48, err = eQryErSynUnbalPar
AutoFlange-Compound joint AutoFlange cannot connect with two simple joints."
Plant 3D Piping Errors screenshot

  • MixedAutoFlange-Compound joint MixedAutoFlange can not connect with two simple joints.

Plant 3D Piping Errors

One or more items have caused an error.
Error message: Cannot connect parts.
No connection defined for end types FL and SO in the config file.
MixedAutoFlange-Compound joint MixedAutoFlange cannot connect with two simple joints.

Plant 3D Piping Errors screenshot
 

Causes:

  • A flange is inserted into a pipeline. Therefore, the compound joint "Auto Flange_<specific name>" is tried to use. The Auto Flange-compound-joint normally inserts another flange onto the pipe.
  • This flange is the one with the highest priority in the specific spec.
  • As a mandatory property the facing is used. But the second flange doesn't have the mandatory facing set to the same as the first flange (in this example the first flange has the end code "LFF". So, the connection failed.
  • No flange found, with the same Nominal Diameter, Pressure Class and Facing, in the spec that could connect to the pipe.
  • Any of the spec components are corrupted. For example: Flange/Bolt/Gasket.
  • "This joint connects imperial to metric components" option is checked in simple joints or compound joints under Piping Connection Settings.
     

Solution:

Follow any of the below solution steps:

Option-1

  • 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.

    If not resolved, it might be a yellow triangle with a black exclamation mark. In this case:
  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.
OR

                   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 property "Facing".
  4. Apply and close Project Setup.

Option-2

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

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

Option-3

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

    Replace the corrupted components in the spec.

Option-4

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

  1. Open the project setup.
  2. Navigate to Plant 3D DWG settings > Piping Connection Settings.
  3. In simple joints or Compound joints, Select Flanged joint or Auto Flange joint.
  4. Click the Modify button.
  5. Deselect the option "This joint connects imperial to metric components".
  6. Click the Modify button.
  7. Click OK to Save and exit the project setup.

Products:

AutoCAD Plant 3D;

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