As one example, an apparatus configured to regulate flow in an exhaust passage of an internal combustion engine system is provided. The apparatus comprise a housing disposed within the exhaust passage defining a first region and a second region, where the first region includes a first stopper and a first valve plate, where first stopper completely surrounds first region, and the first valve plate seats on the first stopper to seal first region, and where the second region includes a second stopper and second valve plate, where second stopper completely surrounds the second region, and the second valve plate seats on the second stopper to seal second region, and where the first stopper; a translating mechanism coupled between first and second plates, the mechanism coupling the first and second plates through a set of gears in the housing, such that forces acting to close first plate are translated through mechanism to act to open the second plate, and vice versa; and an actuator to move the translating mechanism, where such movement causes both the first and second plates to rotate concurrently.