Water mains were once made of steel and these would often develop small leak holes. These might have started as pin-hole leaks; but, could be eroded by flowing water into larger holes. I saw many cases of steel mains installed from the 19-oughts to the fifties. By the time that the company got around to replace some of these there were whole sections with nothing but repair clamps. The interior rust build up could cause "red water" problems as indicated below.
Cast Iron and Ductile Iron pipes normally do not rust out. If not cement lined inside there might be mineral and rust buildups that would reduce the flow of water and high volume flows (like due to flushing Fire Hydrants or fighting fires) would stir the rust up and cause "red water" which was not well liked by people using their washing machines or taking showers and washing their hair. Almost all Ductile Iron Pipes now have a cement lining and a bituminous coating.
A.C.pipe came along in the 1950s. A.C. meaning "asbestos cement" -- cement pipe with asbestos reinforcing fibers -- with a trade name of "Transite." No rusting and thought to have a long life-cycle. Couple of problems. Tree roots might grow above and below the pipes and as they grew bigger in size the pressure could crack the AC pipe. The other problem was the asbestos -- field cutting would cause fly which could be inhaled; similarly the factory milling of the ends for the rubber gaskets would cause fly in the factories. 40 years ago some AC pipe systems in up-state New York were found to have water that was chemically deteriorating the cement and releasing the asbestos into the water supply -- that ended the manufacture of AC pipe.
PVC pipe was being introduced about 40 years and this initially was available in the smaller sizes (4", 6, 8", 10", and 12" diameter). These were followed by larger size PVC pipe. PVC pipe is made at various pressure ratings and purposes and is colored to indicate use: blue = domestic water 150PSI+ test; green = low pressure for storm water or sewage lines; purple = same pressure ratings as domestic but to be used for recycled (non-potable) water.
Brian Norden
I worked in the domestic water industry as a pipe and facility designer for most of my working life.
