Click Home tabCreate Design panelSet Pipe Network CatalogFind.
On the Pipe Network Catalog Settings dialog box, click the folder icon to browse to the location of the pipe network catalog folder. This is the top-level folder containing all the pipe network part catalogs. For example, this folder contains subfolders for imperial and metric pipes and structures.
The default part catalog location is C:\ProgramData\Autodesk\C3D <version>\enu\Pipes Catalog.
Select the desired folder and click Open.
You may want to specify different pipe and structure catalogs, if they are available.