WATER cooler or water dispenser is a device that cools and dispenses water. There are TWO main types of water cooler.Instantaneous type water cooler/pressure type water cooler: There is instantaneous cooling as well as supply of cold water and there is no float VALVE in the unit.Storage type water cooler: This has a facility of storage tank which stores cold water and then it is supplied for consumption. A float valve is PROVIDED for stopping water flow once the tank is full.