due to corrosion.2.Main Materials Used in IITK: Centrifugally cast iron (CI) Galvanized iron (GI) Steel Stainless steel Cast iron PVC (Poly venyl chloride) RCC (Reinforced concrete council)Centrifugally cast iron vs. Galvanized iron: CI is more resistant to corrosion in soil and water environment as compared to GI. But CI cannot be threaded much frequently, as it will corrode very fast near the threads and thus will lead to breakage and leakage. So CI is used only, where long pipes are needed. For small length pipes, like those in houses, GI is the better option. Thus CI is majority used for pipelines for water supply, and GI is also used where small length pipes are needed.3.Inspection:In most of the cases corrosion is recognized by visual inspection. Steel:Corrosion of steel is easily recognized because the corrosion product is red rust. RCC:RCC(Reinforced Concrete Council) is used in all the building constructions. There are always voids present in the structure. In these voids moisture will collect and will lead to corrosion. But this corrosion is usually not spotted out till 10-15 years. It is noticed when after 10-15 years cracks appear on the surface. Electric power supply pillars:The power pillars get corroded very soon in top region, where two different metals are joined.In some cases inspection can not be done on regular intervals, e.g. underground pipelines.4.Causes:There can be many reasons of corrosion. In different systems there can be different mechanism of corrosion. Iron based alloys:When iron base alloys corrode, dark corrosion products usually form first on the surface of the metal. These products are protective. However, if moisture is present, this ferrous oxide coating is converted to hydrated ferric oxide, which is red rust. This material will promote further attack by absorbing moisture from the air.Except this the presence o...
