One of the most important accessories you can have for your steam boiler is a water softener. Raw water having high hardness is passed through a sodium based resin, where hardness related calcium and magnesium ions are replaced with the sodium ions of the resin and treated water coming out of its outlet having zero hardness. This type of plants are installed in all the process industries where water of low hardness is required such as in feed water for boilers and cooling towers.