The process involves the insertion of a tight-fitting high density Polyethylene (HDPE) liner pipe inside of a steel pipe. This takes advantage of the mechanical strength of the steel pipe combined with the abrasion and corrosion resistance of the HDPE liner pipe. Because of the tight fitting design, the liner pipe is radially compressed (rolled down) to reduce its outside diameter during the insertion process. Insertion lengths can vary from short pull lengths to long pull lengths of up to 1,500 meters, depending on the pipe diameter and topographical contour of the pipeline.

The roller reduction method involves the radial compression of the HDPE liner pipe by passing it through a series of roller reduction units during the insertion process. Once installed, the HDPE liner expands within the steel pipe and fits tight against the pipe wall.