Just a quick note that catch my attention, in fact a recurrent question. If the Pipe is of type Curved, how can we access/read the geometry information?
In fact, there is a Pipe.Curve2d property will return a CircularArc2d, which has a Radius property, and some others, like Center. If you need a point as a specific position, try EvaluatePoint at a specific parameter of the curve, which is a BRep API from AutoCAD.
Pipe myPipe = // read the pipe
myPipe.Curve2d.EvaluatePoint(0.5); // middle of the arc, for instance
