High-Performance Debris Filter with Redundant Safety Technology The PR-BW 400 is an Automatic Backwash Filter for the separation of macrofouling (debris) from liquids, especially from cooling waters for turbine condensers and heat exchangers. The main characteristics and outstanding features of this filter are its 4-fold redundant operational safety together with its capability to reliably discharge even extremely large particles. With regular filtration degrees of 4.5 – 9 mm, the filter is applicable for huge volume flows of up to 100,000 m3/h and beyond. For the first time the world over in this class, filter cleaning has been realised according to the principle of _pressure-relieved backwash (PR-BW). The clear increase in efficiency has marked a new performance standard in the high-end zone. Because of those remarkable features the PR-BW 400 has acquired a firm footing on an international level – at all places where permanent availability, absolute reliability and safety enjoy top priority, for instance in cooling water circuits of power stations and nuclear power plants.