Auto Valveless Gravity Filter (AVGF) which uses sand as filtering media and works on the principal of gravity filtration without any valve, rate controllers etc. This is having two compartments, filtering section and wash water storage compartment. During normal operation water gets filtered while traveling across the sand bed. During filtration suspended solids gets accumulated in the filter bed and differential pressure start increasing which causes the water level to rise in the backwash pipe. When the water level reaches the top of the loop, siphon action start and backwash begins. Wash water flows from the storage compartment through the sand bed and is discharged through the back wash pipe. A siphon breaker ends the wash cycle.

The major application of these filter are for raw water clarification, site stream filtration of cooling tower etc i.e. mainly for low turbidity applications.