Propagate Object Properties

This task shows you how to propagate nominal size using the Properties dialog box. This function allows you to propagate a change in size value throughout a network path with certain limitations. To explain further, if you place a 4-inch valve on an 8-inch line, and propagate the nominal size of the valve, then the line and all its members will change to the 4-inch size.  
To propagate an attribute, e.g., nominal size or equivalent diameter, you must select an object in your document that has such an attribute. The attribute can be propagated when you see the Propagate button on the HVAC tab. See Rules below for details on the requirements and limitations of attribute propagation.

Only the property 'nominal size' can be propagated - nominal size2 in the case of a reducer.


To select the component in your document whose attribute is to be propagated, right click the object in the specifications tree and select Properties from the menu. Alternatively, select the object and click Edit - Properties.
2. In the example below, the Properties dialog box is displayed with the HVAC tab open and the Propagate button visible. In this case, we have a volume damper placed on a 40 inch line.

3. In the Properties dialog box, change the value for Equivalent Diameter to 48 in. Click the Propagate button. The Attribute to Propagate dialog box opens showing the attributes that can be propagated. Click on Equivalent Diameter.

The objects in the propagate path for the attribute 'Equivalent Diameter' will highlight. If a different attribute is then selected, the new path will highlight. 

4. Click OK in the Attribute to Propagate dialog box to return to the Properties dialog box. Click Apply or OK. The equivalent diameter of the volume damper will be overridden to 48 inches and all objects in the network with a 'equivalent diameter' attribute will be changed to 48 in. See Rules, below, for requirements and limitations on propagating an attribute.


This function allows you to propagate a size value over a network path. Propagation may occur in all directions from the propagating object with the following exceptions which limit the extent of the "network":

  • Objects of a different discipline than the propagating object.

  • Objects with no nominal size, or equivalent size attribute.

  • End of a network path (i.e., no connectivity).

  • Off-sheet connectors.

  • Branch to Main Route.

  • Main Route to Branch.

  • Object in a different logical line (Line ID).

  • Nozzles.

  • Reducers - one side is affected.

  • Switching Valve (3-way) or a Switching Valve Function (4-way).