Valve device (10; 110; 210; 310) for controlling a fluid flow, in particular for controlling a cold air flow in a household appliance, such as a fridge; said device (10; 110; 210; 310) comprising a support structure, on which the following elements are mounted: - a plug arranged for assuming a plurality of operating positions including an opening position and a closing position, in which the plug is adapted to at least partially free and respectively obstruct a passage, which is meant for the fluid flow to get through; - a mechanism arranged for moving and holding said plug between said operating positions; and - an opening actuator and a closing actuator, for separately acting on said mechanism, so that said mechanism moves said plug between said operating positions, namely towards said opening position and towards said closing position, respectively, due to an electric current which is supplied to said opening actuator and to said closing actuator respectively; said opening and closing actuators comprise an opening electrical conductor and respectively a closing actuator, each of them being made of a shape-memory alloy and constrained to said mechanism; wherein said mechanism comprises a rotatory member rotatable around a rotation axis (X-X) and on which said opening electrical conductor and said closing actuator act; wherein said rotatory member fulfills the function of a rocker lever having two arms (23a, 23b), which extend on opposite sides relative to rotation axis (X-X); wherein the rotation of rotatory member around rotation axis (X-X) is determined by the operation of the opening electrical conductor and respectively of the closing electrical conductor, which act on opposite sides relative to rotation axis (X-X) upon opening arm and respectively upon closing arm; charaterised in that said mechanism further comprises a rotatory element torsionally constrained in an elastic manner to said rotatory member and cooperating with said plug so as to move said plug to said opening position and to said closing position. - a plug arranged for assuming a plurality of operating positions including an opening position and a closing position, in which the plug is adapted to at least partially free and respectively obstruct a passage, which is meant for the fluid flow to get through; - a mechanism arranged for moving and holding said plug between said operating positions; and - an opening actuator and a closing actuator, for separately acting on said mechanism, so that said mechanism moves said plug between said operating positions, namely towards said opening position and towards said closing position, respectively, due to an electric current which is supplied to said opening actuator and to said closing actuator respectively; said opening and closing actuators comprise an opening electrical conductor and respectively a closing actuator, each of them being made of a shape-memory alloy and constrained to said mechanism; wherein said mechanism comprises a rotatory member rotatable around a rotation axis (X-X) and on which said opening electrical conductor and said closing actuator act; wherein said rotatory member fulfills the function of a rocker lever having two arms (23a, 23b), which extend on opposite sides relative to rotation axis (X-X); wherein the rotation of rotatory member around rotation axis (X-X) is determined by the operation of the opening electrical conductor and respectively of the closing electrical conductor, which act on opposite sides relative to rotation axis (X-X) upon opening arm and respectively upon closing arm; charaterised in that said mechanism further comprises a rotatory element torsionally constrained in an elastic manner to said rotatory member and cooperating with said plug so as to move said plug to said opening position and to said closing position.