Wandfluh has equipped the existing roller valve with a more robust actuating mechanism and increased the hydraulic peak performances. The valve can now switch a volume flow of 30 l/min at up to 350 bar. The actuation roller can also absorb higher transverse forces and is very well protected against contamination and corrosion. The direct operated valve of nominal size NG4 is available as a 4/2-way execution with the designation WDTFA04. This valve is used for applications in which electrical elements are consciously dispensed with or where a purely mechanical actuation is required.