Backwash Control Valves are 3-way control valves operating with line pressure or an external pneumatic pressure in filtration systems. The valve operates in filtration and backwash mode in coordination with the filter elements in the system. The diaphragm assembly of the valve works in 2 directions. In the filtration mode, the valve opens the discharge path by changing the direction of the diaphragm assembly when switching to the backwash mode. Thus, it prevents the mixing of clean water and dirty water in the system and cleans the filter elements in the best way.