Extraction of 3D hollow pipe from 3d solid pipe
 

I am interested in knowing how to extract a smooth 3D hollow pipe from an approximate 3D Y-shaped solid pipe. Eventually the goal is to generate a mesh for the hollow pipe.

I am wondering which software will be best to do it.

I also have coordinates or vertex points of 3D solid pipe, is it possible to import the vertex point and construct hollow pipe.

Any hint or link about it would be great.

Thanks

jay

Example Figures: 2D and 3D
 

found my answers