A Typical two-bed DM Plant consists of two MS Rubber lined Pressure vessels connected in series along with its internal fittings. The first unit consists of high capacity strongly acidic cation exchange resin, which converts positive ions of salt and replaces them with hydrogen ions to form respective acids, which are absorbed in next vessel by strongly basic anion exchange resin. The water obtained by this process shows conductivity less than 20 µ S / cm at 25 Deg C and total dissolved solids less than 10 ppm. Further high purity water can be achieved by Mixed Bed Deionisers, which are designed to produce high purity treated water. They can be used as polishing units after two bed DM Plant to obtain high purity water. Mixed Bed Deionisers are single column units, filled with strongly acidic cation and strongly basic anion exchange resins mixed together.