Tangent lines from a pipe

Perhaps this will help visualize it
The tangent lines are coplanar with the extracted isocurves.
The surface will be formed by lofting the vertical lines (that are tangent to the cylinder surface)
The cylinder will be trimmed at the projected line


Ideally, there would be an infinite number of vertical lines

How do you extract n isocurves on the surface of the pipe?

like this:

Would it be better to use a cylinder solid?
Would it be better to create a surface with sweep 1 curve?