Patent ID: 8671989

Claim:
A drive arrangement for a valve device, the valve device having a closing member, the closing member having a movable drive element for making an operative connection with the closing member, pre-tensioning means for exerting a pre-tensioning force on the drive element for holding the closing member in a base position against working forces acting on the closing member, and driving means capable of moving the drive element from the base position against the pre-tensioning force in the direction of the working forces, wherein the pre-tensioning means comprises compressed air enclosed in a pre-tensioning container, with a static pressure for producing the pre-tensioning force, wherein the volume of the pre-tensioning container is a multiple of the stroke volume of the drive element and the pre-tensioning container is provided with connecting means, the connecting means being configured for connection to a second pre-tensioning container of a second drive arrangement of a similar type, wherein the movable drive element is movable independently of a movable drive element of said second drive arrangement, wherein the drive arrangement comprises a valve-side pressure chamber and wherein the valve-side pressure chamber is so constructed and arranged as to be capable of increasing a static pressure in the valve-side pressure chamber until the pressure in the valve-side pressure chamber exceeds the static pressure in the pre-tensioning container, to move the drive element.