In the Flexible Seat Valve, the seat is not a passive, rigid component but an active flexible control element. The seat can be made slightly concave or convex. This changes the average pressure in the gap and the opening force on the poppet. The result is a direct and dynamic control of the valve opening.

The flexible seat valve fulfils the need for fast and accurate control of hydraulic systems. The deflection of the seat membrane is only 10 - 100 µm and can be realized in many ways:
- pressure actuated by changing the pressure at the back side of the seat membrane
- force actuated for instance by means of a piezoelectric element
- temperature actuated by means of thermal expansion of the seat.