A filling device for filling a receptacle, comprising: a tank containing a fluid; a valve body which mainly extends along a longitudinal direction; an inlet communicating with said tank; a dispensing nozzle for dispensing fluid to the receptacle; a passage for the fluid, obtained inside the valve body between the inlet and the dispensing nozzle; a shutter that can be moved inside said valve body so as to assume at least a first position in which it is at a first predefined distance from said dispensing nozzle, a second position in which it engages said dispensing nozzle so as to close it completely and a third position in which it is at a second predefined distance from said dispensing nozzle, less than the first predefined distance; a slider slidably inserted in the valve body, said shutter being integrally fixed to a first end of the slider in proximity to the dispensing nozzle; said filling device being configurable at least in: - a filling status in which the tank contains a food-grade fluid and the shutter is in the first position so as to allow the dispensing nozzle to dispense the food-grade fluid to the receptacle; - a sanitisation status in which the tank contains a sanitisation fluid and the shutter is in the second or third position, characterized in that the filling device further comprises an annular sleeve slidably mounted outside the valve body and comprising a plurality of magnetic rings alternating with a plurality of ferromagnetic rings, said slider comprising a core made of ferromagnetic material to which a coating is applied made of thermoplastic polymer, wherein the core of said slider has a central portion having a cylindrical extension along said longitudinal direction and a plurality of radial projections having an extension orthogonal to the longitudinal direction. a tank containing a fluid; a valve body which mainly extends along a longitudinal direction; an inlet communicating with said tank; a dispensing nozzle for dispensing fluid to the receptacle; a passage for the fluid, obtained inside the valve body between the inlet and the dispensing nozzle; a shutter that can be moved inside said valve body so as to assume at least a first position in which it is at a first predefined distance from said dispensing nozzle, a second position in which it engages said dispensing nozzle so as to close it completely and a third position in which it is at a second predefined distance from said dispensing nozzle, less than the first predefined distance; a slider slidably inserted in the valve body, said shutter being integrally fixed to a first end of the slider in proximity to the dispensing nozzle; said filling device being configurable at least in: - a filling status in which the tank contains a food-grade fluid and the shutter is in the first position so as to allow the dispensing nozzle to dispense the food-grade fluid to the receptacle; - a sanitisation status in which the tank contains a sanitisation fluid and the shutter is in the second or third position, - a filling status in which the tank contains a food-grade fluid and the shutter is in the first position so as to allow the dispensing nozzle to dispense the food-grade fluid to the receptacle; - a sanitisation status in which the tank contains a sanitisation fluid and the shutter is in the second or third position, characterized in that the filling device further comprises an annular sleeve slidably mounted outside the valve body and comprising a plurality of magnetic rings alternating with a plurality of ferromagnetic rings, said slider comprising a core made of ferromagnetic material to which a coating is applied made of thermoplastic polymer, wherein the core of said slider has a central portion having a cylindrical extension along said longitudinal direction and a plurality of radial projections having an extension orthogonal to the longitudinal direction.