A valve mechanism for an air condition circuit of an air condition system may include a valve housing enclosing a fluid duct for passing a fluid flow, a closure body arranged movably in the fluid duct between at least a closed position and an open position, and adjustment element operably connected to the closure body to move the closure body between the open position and the closed position, and a noise reduction device configured to facilitate a reduction of an operating noise when the fluid flow through the fluid duct. The noise reduction device may be disposed at one or more of the closure body, a valve seat, and the adjustment element.