Infrastructure Parts Editor and Inventor for Civil 3D
Joe Hedrick, a Technical Specialist at IMAGINiT, delivers a Civil Engineers Guide to Navigating Autodesk Inventor and the Infrastructure Parts Editor.
This is a decent tutorial on what you need to know and do to create custom gravity and pressure pipe parts for Civil 3D and/or Infraworks.
From the IMAGINiT YouTube Channel.
More than a few useful need to know essentials to help demystify the Parts Editor, the Inventor basics, and the entire customization process mechanics.
Remember the most important fact - "It is easier to edit than create."