New Developments in Deposition of Calcite Linings in Small-Diameter Pipe

ately after cleaning. A cement lining provides an effective coating, but its installation is expensive and time consuming for mains 8 in. or less in diameter because of bypass piping and the limitations of the lining equipment. Many attempts have been made to lay down a coating of calcium carbonate gradually by precipitating this compound from the calcium compounds naturally present in the water flowing through the main. Generally, these attempts have been unsuccessful. The deposits are often porous, rough, and slow to form. If a dense and hardsheath CaCOs deposit could be obtained, it could be the answer to the problem of protecting such small, unlined cast-iron mains.