Cast iron pipe

Cast iron pipe is a pipe which has had historic use as a pressure pipe for transmission of water, gas and sewage, and as a water drainage pipe during the 17th, 18th, 19th and 20th centuries. It comprises predominantly a gray cast iron tube and was frequently used uncoated, although later coatings and linings reduced corrosion and improved hydraulics. In cast iron pipe, the graphite forms flakes during the casting process, when examined under a microscope. Cast iron pipe was superseded by ductile iron pipe, which is a direct development, with most existing manufacturing plants transitioning to the new material during the 1970s and 1980s. Ductile iron pipe is different than cast iron, because the introduction of magnesium during the casting process causes the graphite to form spheres (graphite nodules) rather than flakes. While this allows the material to remain castable, the end product is much tougher than cast iron, and allows elastic behavior at lower stress levels. Little cast iron pipe is currently manufactured, since ductile iron pipe is widely accepted as a superior product. Many public utilities, municipalities, and private industries still have functional cast iron pipe in service to this day. Cast iron pipe is a pipe which has had historic use as a pressure pipe for transmission of water, gas and sewage, and as a water drainage pipe during the 17th, 18th, 19th and 20th centuries. It comprises predominantly a gray cast iron tube and was frequently used uncoated, although later coatings and linings reduced corrosion and improved hydraulics. In cast iron pipe, the graphite forms flakes during the casting process, when examined under a microscope. Cast iron pipe was superseded by ductile iron pipe, which is a direct development, with most existing manufacturing plants transitioning to the new material during the 1970s and 1980s. Ductile iron pipe is different than cast iron, because the introduction of magnesium during the casting process causes the graphite to form spheres (graphite nodules) rather than flakes. While this allows the material to remain castable, the end product is much tougher than cast iron, and allows elastic behavior at lower stress levels. Little cast iron pipe is currently manufactured, since ductile iron pipe is widely accepted as a superior product. Many public utilities, municipalities, and private industries still have functional cast iron pipe in service to this day. The oldest cast iron water pipes date from the 17th century and were installed to distribute water throughout the gardens of the Chateau de Versailles. These amount to some 35 km of pipe, typically 1m lengths with flanged joints. The extreme age of these pipes make them of considerable historical value. Despite extensive refurbishment in 2008 by Saint-Gobain PAM, 80% remain original.