S.Steel Cluster Filter CF28 Pure Aqua S.Steel Cluster Filter. Multi-cartridge filters of the CF series are designed for fine purification of water and chemical solutions from suspended solids. Filters can be used both as part of drinking water treatment systems and for water treatment systems for boilers. The design of filters uses the principle of thin-layer filtration through a highly porous material, which is used as cartridges made of polypropylene, polyester and activated carbon. The material of which the case is made is stainless steel SS304 or SS316. Flange in/outlet available Housing Material : SS304, or SS316 on request. Entire set of filter cartridges is removed at one time for cleaning replacement. Working Temperature: 1~50°C