US Patent 7503203 Rotary valve and analytical chromatographic system using the same

There is provided a rotary valve for fluid analytical systems. The present valve provides improved characteristics such as an extended lifetime. The valve can fulfil different fluid analytical functions and can be a multi-ports and/or multi-positions valve. The valve is provided with extra recesses in the rotor and extra ports in the stator. These recesses allow to cancel the effect of any possible leaks by evacuating them. Such a valve then prevents cross-port leaks and can advantageously be used in highly critical applications. Moreover, the present valve can be used in an analytical system which is advantageously self-diagnostic.