The Add Catalogs option, available from the Home ribbon, displays the Open dialog allowing you to navigate the directory where your catalogs are stored. From there you can select new catalogs to use to build the active the specification.
Note: OpenPlant Project Administrator provides a set of Imperial, Metric and Mixed Metric catalogs which are installed in the %Standards\OpenPlant\Catalogs directory found under the local workspace.
Select a catalog(s) to add to the spec and click Open to load. Multiple catalogs can be selected by holding down the Ctrl button as you make your selections.
Once the catalogs are loaded, you can continue creating the spec by adding a Spec Header and Spec Sections.