CADWorx Plant II tab: Flange O.D. 
Pipe Ends toolbar: Flange O.D.
Command line: ENDFLG
Draws a circle around the diameter of the selected flange at the size and specification currently defined for the drawing. The circle, which represents the end view of a flange, is placed at the center of the selected point.
The resulting circle has centerlines that are on the default CL layer.