Flex   |  
 Checks if given type is valid flexible duct type. 
 Namespace: Autodesk.Revit.DB.Mechanical
Assembly: RevitAPI (in RevitAPI.dll) Version: 25.0.0.0 (25.0.0.0)
| Exception | Condition | 
|---|---|
| ArgumentNullException | A non-optional argument was null | 
 A type is valid for flexible duct if it can be used to the flexible duct element.