Protective system for underground pipes

Abstract From the Canadian patent

A method of protecting underground pipe from corrosion in a region in which it extends through a casing and is subject to the deleterious action of water accumulated in the casing. The ends of the casing are sealed to provide a closed chamber around the pipe. A treatment substance capable of mixing with the water and reducing or neutralizing its deleterious effect is introduced to the chamber. Thereafter a corrosion-resistant compound is pumped into the chamber to substantially fill the chamber with the compound and displace all or much of the water from the chamber.