Creating Pipeline Routing with Follow
Using the follow commands in the routing environment toolbar, you can create line segments based on sketched geometry, a curve, an existing pipeline, or coincident with an axis without having to set a start point.
Following Sketched Geometry
You can create pipe line segments according to your sketch when you use the > 
Follow Sketch button. This routing action can be useful when routing a pipe line with respect to equipment or some structural elements. The new segments must lie in the same plane. The following rules apply:
Follow Sketch button. This routing action can be useful when routing a pipe line with respect to equipment or some structural elements. The new segments must lie in the same plane. The following rules apply:• Following sketched geometry does not create a connection between the existing pipe end and new sketched segments, even if both end points are coincident. To join two endpoints, even if they are immediately on top of each other, use 
To Pnt/Port (to point/port) or 
Connect (to connect).
To Pnt/Port (to point/port) or Connect (to connect).• Bend radii or miter corners are added automatically to sketched geometry.