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When a valve which is used to shut off the discharge volume of a medium with challenging flow characteristics is operated infrequently, a bridging effect often results. This initially tends to occur between valve disc and liner, but often progresses so far that the material flow is blocked through to the silo. The valve disc and liner are then exposed to disproportionately high frictional forces when the valve opens. Time-consuming countermeasures can be avoided in advance in many cases by using a ViDos valve: a vibrator mounted on the lower shaft causes a light linear vibration of the valve disc. The frequency of the vibration is controlled via the air pressure. The vibrations keep the medium in motion and effectively reduce bridging. Substances that are already compressed or have adhered to the disc are loosened and detached. A mounted positioner enables different coarse/fine dosing positions to be reached, so that the medium can still be discharged with high precision even with small opening angles. The valve liner has a damping effect on the valve body during this process. The ViDos disc is designed as a wafer pattern butterfly valve and is available in nominal diameters DN 150 to DN 400 (also with stainless steel body up to DN 300). It is suitable for temperatures from -10°C to +200°C (depending on medium, pressure and material) and is used in pneumatic materials handling, power plant technology and the food industry.