Auto-Dimension MEP is an add-in that helps you insert dimensions and tags into the current view. You can use it for pipes, ducts, or cable trays.

For round pipes and round ducts, you can filter by diameter and length. The app will get pipe diameter and length from your project. It helps you to quickly select the pipes that you need.

For rectangle/oval ducts and cable trays, you can filter by height and width.

Additionally, the app can help you insert dimensions and tags into a linked file, however only in Plan View.

Quick Dim command can help you insert dimension into any picked pipe/duct/cable tray and family instances.