Deterioration of Pipes
Even when water mains are properly installed, the pipes will deteriorate over time. This deterioration can be slowed by matching the pipe material to the soil or by wrapping the pipe.
Cast iron, ductile iron, and galvanized iron pipes can all be weakened in just a few years when laid in aggressive soil. To prevent this type of damage, the soil should be tested before laying the pipes in the ground. If necessary, the pipes can be wrapped in plastic during installation to protect the metal from the soil. The Ductile Iron Pipe Research Association can provide detailed information on the wrapping procedure.
The type of soil is also an important consideration when installing plastic pipes. Organic chemicals, especially solvents and gasoline, will weaken PVC pipes, causing the pipe to expand and rupture. The operator in charge of ditching should be alert for any unusual odor when removing soil during the construction of the distribution system. The odor may be a sign of a chemical spill, which may remain in the soil for many years and weaken PVC pipes.
Gasoline and diesel can pass through the walls of polyethylene pipes even when the water inside is under high pressure. For this reason, plastic pipes should never be installed in the vicinity of gas stations. Instead, ductile iron and copper pipes are recommended for service lines in the vicinity of gas stations
------------------------- By Jetsun