Nozzle screen The treatment media. Because of their non-clogging design strainer are effective in a wide Range of water treatment and other industrial applications. Common applications include under Drain media retention elements or flow distributors in demineralizers and water softeners in Pressure and gravity sand filters. Strainers can also be used as collectors at the bottom of The vessels by installing a number of strainers uniformly across a tray plate. The combination Of high open area and a non-plugging slot design makes this nozzle/collector application Popular