Raw water is passed through the pressure sand filter, the filter media is supported on gravel bed that consists of multiple layers of Graded quartz sand, Fine sand, Super fine white sand and pebbles of progressively larger sizes. During the filtration cycle the filter bed retains the dirt and suspended particles from the water and accumulates within the filter the water and accumulates within the filter bed. As the filtration progress the filter media gets loaded with retained suspended particles, this results in a continuous increase of pressure drop across the filter, when a predetermined pressure drop level is achieved the filter is shut down for cleaning.
