To Add Dimension Exclusions

In the Project Setup dialog box, expand Isometric DWG Settings. Click Dimensions.
On the Dimensions pane, in the Iso Theme list, select the iso theme for which you want to modify the dimension styles to different dimension types.
From any tab (Under End to End (Overall), String, or Locating), under Exclusions box, click Add.
In the Piping Component Selection dialog box, Standard tab, do the following:
- Specify one or more components as dimension exclusions.
- Specify one or more end types to components as exclusions.
- Specify one or more additional conditions to components as exclusions.
Click Advanced tab and enable the Use filter to specify exclusion option to select any existing filter as an exclusion. Click Add Exclusion.
From any tab (Under End to End (Overall), String, or Locating), select any exclusion and click Delete Exclusion Point to delete the selected exclusion.