The category id of duct curves. It will be OST_DuctCurves, OST_FlexDuctCurves, or OST_PlaceHolderDucts.
Namespace: Autodesk.Revit.DB.Mechanical
Assembly: RevitAPI (in RevitAPI.dll) Version: 26.4.0.0 (26.4.0.0)
Syntax
C#
public ElementId CategoryId { get; }