REPLACING UNDERGROUND PIPES: HYDRAULIC JACK PUSHES NEW PIPE BEHIND CONE EXPANDER WHICH BREAKS UP OLD PIPE

摘要

The apparatus and technique of the invention constitutes a hydraulic jack system for pushing sections of new pipe which, in turn, pushes a sleeve-cone expander arrangement to break up the old pipe and define a straight path for the new pipe. Apparatus is employed to determine the skin friction and the penetration friction, and to dispense a lubricant to reduce such frictional forces.