Overflow valves control an adjustable, constant pressure upstream of the valve. A compression spring keeps the valve closed, it opens when the upstream pressure rises. The valves are pre-set, but can also be easily adjusted on site by the user without further special tools. This ensures an exact adjustment of

the pre-pressure, which fulfils important functions especially in modern industry and plant construction, where highly optimised systems determine the market. Depending on the sealing material, the overflowers are suitable for liquids, gases and steam. They are resistant to petrol, oil and benzene.