A valve lift mechanism for actuating a valve in the vertical direction, and a regenerative thermal oxidizer including the valve and lift mechanism is disclosed. The valve is allowed to move vertically and oscillating rotary motion is possible. Vertical movement is achieved using the valve lift mechanism without the use of compressed air. In certain embodiments, the valve lift mechanism includes a torque motor. Preferably, a non self-locking screw jack is used to adjust the vertical height of the valve. Vertical movement can reduce the torque needed to rotate the valve, and also facilitates servicing of the valve. For example, if the valve experiences high temperature, and consequently expands, rotating the valve against the mating seal plate can be difficult, if not impossible. By lowering the valve slightly, the frictional forces between the valve and the mating seal plate are reduced, allowing freer rotational movement of the valve.