UNDERDRAIN SYSTEM

Introduction : In drinking water treatment plants Rapid sand gravity filter beds are used for filtration of water. Multiple layers of different sizes of gravel and sand are used through which the water percolates down and some underdrain system is provided to take away the filtered water without disturbing the filter media.HEAD - LATERALS SYSTEMBased on the experience unique to Johnson- a company world wide specialist in filtration - offersUnderdrain System, a solution to problems occurring in filters for the treatment of water.The unique Header-Lateral System utilises Johnson's world renowned Vee Wire Screen Technology and experience. Direct Retention of Filtering Mediumby Johnson Vee Wire Screen, wound around the perforated base pipe lateral - designed for thecollection and the distribution of water. Non Clogging "V" shaped slots hence No Jamming or Plugging Problems. The design ensures very robust construction. Separate Air HeaderThe system having a separate air headerwith separate air nozzles to every laterals, ensures even air distribution to the entire bed and allows to give effective combined backwash.