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Pipe Extraction

Pipe extraction is a trenchless method, which can remove an existing pipe for disposal and replace it with a new pipe - typically a high density polyethylene (HDPE) or polyethylene (PE) pipe. There are several systems that have been developed to remove existing service lines while at the same time replacing them with a new pipe. Most all involve pulling out the existing pipe while simultaneously pulling in the new pipe. An example of a typical pipe extraction system involves a steel cable fitted with cones that can be expanded to grip the internal wall of the existing service line. The cable is fed through the service line and attached to the PE pipe that is to be installed. The cable is then winched back or pulled using a hydraulic assembly -- extracting the existing service line and pulling in the new pipe. A pushing device also may be attached to the back of the service line to assist in the extraction of the service. Another technique involves feeding a string of rods through the existing service line. The rod string is connected to an adapter head. The adapter head, which is larger than the service line, is attached to the replacement pipe. A hydraulic assembly located in the exit pit pulls the rods back through the service line thus extracting and splitting the line as it exits the hole, while simultaneously pulling in the new pipe.