Observe the User Defined HVAC Fittings form

In HVAC Designer Application and from the HVAC window select the Category User Defined Fittings.

The Specification created is displayed, and the selectors available to select the six catalogue items. At the moment if you select any of these they will all be the same as the copied component /RSTHRE. So the next stage is to edit these components to be unique to match the initial requirements.