Fix Part Direction

Fix the direction of a part if you wish it to retain its original direction. Select the Position fixed constraint. The direction of a pipe line added in the vertical direction (Z axis) is the only one that will be automatically fixed.

1. Select a pipe/duct.
2. Right-click to open the context-sensitive menu.
3. Select Constraints from the menu.
4. Select the Position fixed checkbox.
5. Confirm by clicking OK.

Position the Parts of a Pipe or Duct Line Using Constraints