KIESELMANN double seat valves were developed according to the EHEDG criteria and are among the most modern leakage-proof valves of our time. They are used for the mixture-safe separation of incompatible products in automatic process plants. The closed valve avoids mixture due to two independent valve disks with depressurized leakage discharge. In case of a damaged sealing, the process medium escapes from the valve without pressure. The leakage space can be cleaned by lifting the upper valve disk or lowering the lower valve disk respectively. KIESELMANN double seat valves stand for low operating, maintenance and repair costs and are the basis for an economic process.