Demineralised Water also known as Deionized Water, water that has had its mineral ions removed. Mineral ions such as sodium, calcium, iron, copper, etc. cations and anions such as chloride, sulfate, nitrate, etc. are common ions present in the water. Deionisation is a physical process using specially manufactured ion exchange resins that provide an ion exchange site to replace the mineral salts in water with water forming H + and OH- ions. Because most water impurities are dissolved salts, deionization produces a high purity water that is generally similar to distilled water, and this process is fast and without accumulation of scale. Demineralization technology is the proven process for water treatment. A DM water system produces mineral free water operating on the principles of ion exchange, degassing and polishing. The Demineralized Water System finds extensive application in the field of steam, power, process and cooling.