US Patent 6966950 Method and apparatus for treating underground pipeline

A system for internally filling a joint or other discontinuity in a pipeline. The system includes a flexible conduit, a fill device removably connected to said flexible conduit, wherein the fill device is constructed and arranged to apply a fill material to an interior surface of said pipeline to fill one or more gaps in the pipeline, and a propulsion unit connected to at least one of the flexible conduit and the fill device that propels the flexible conduit through said pipeline.