A system comprising a filling valve for filling liquid into a vessel and the vessel having a cylindrical portion with an opening (Vm) provided on the top end, an inner diameter expansion portion connected to the cylindrical portion, and a body portion connected to the diameter expansion portion; the filling valve comprising: a nozzle having an outlet on its bottom end and a seat on its interior surface: a stem having a plug provided on its outer periphery that comes into contact with the seat and being liftably traversable inside the nozzle; the stem being able to form a liquid flow passage between the stem and the interior surface of the nozzle; an actuator for opening and closing the plug by raising and lowering the stem; and the stem including a small-diameter segment configuring the lower end, a large-diameter segment positioned above the small-diameter segment and a diameter-reducing segment connecting the small-diameter segment and the large-diameter segment; wherein a small-diameter shell segment, a diameter-reducing shell segment and a large-diameter shell segment are provided inside the nozzle to form a gap configured so that the flow passage matches the shape of the stem; the diameter-reducing shell segment of the nozzle being configured as the seat; wherein the bottom opening of the small-diameter shell segment functions as the outlet of the nozzle; a sealing member configured to make contact with the opening (Vm) of the vessel being provided on the outer periphery of the outlet; the diameter-reducing segment of the stem being configured as the plug; the large-diameter segment above the diameter-reducing segment of the stem being provided with a plurality of helical vanes on its outer periphery that creates a force inducing a spiral flow in the liquid passing through the liquid flow passage, and a bottom end portion of the small-diameter segment of the stem being provided with a bevel with a radially expanding diameter in the downward direction; wherein the helical vanes produces a liquid flow that is configured to resolve spirally down the flow passage between the small-diameter segment of the stem and the small-diameter shell segment of the nozzle and flows out from the outlet so that it is radially spread out and guided to an inner surface of the cylindrical portion of the vessel by the bevel; the filling valve being configured to open the plug when the seal member abuts against the vessel, characterized in that the bevel is extended below the outlet of the small-diameter shell segment of the nozzle and being configured to be positioned inside the cylindrical portion of the vessel while the top end of the bevel is about at the same level with the top end of the cylindrical portion of the vessel. a stem having a plug provided on its outer periphery that comes into contact with the seat and being liftably traversable inside the nozzle; the stem being able to form a liquid flow passage between the stem and the interior surface of the nozzle; an actuator for opening and closing the plug by raising and lowering the stem; and the stem including a small-diameter segment configuring the lower end, a large-diameter segment positioned above the small-diameter segment and a diameter-reducing segment connecting the small-diameter segment and the large-diameter segment; wherein a small-diameter shell segment, a diameter-reducing shell segment and a large-diameter shell segment are provided inside the nozzle to form a gap configured so that the flow passage matches the shape of the stem; the diameter-reducing shell segment of the nozzle being configured as the seat; wherein the bottom opening of the small-diameter shell segment functions as the outlet of the nozzle; a sealing member configured to make contact with the opening (Vm) of the vessel being provided on the outer periphery of the outlet; the diameter-reducing segment of the stem being configured as the plug; the large-diameter segment above the diameter-reducing segment of the stem being provided with a plurality of helical vanes on its outer periphery that creates a force inducing a spiral flow in the liquid passing through the liquid flow passage, and a bottom end portion of the small-diameter segment of the stem being provided with a bevel with a radially expanding diameter in the downward direction; wherein the helical vanes produces a liquid flow that is configured to resolve spirally down the flow passage between the small-diameter segment of the stem and the small-diameter shell segment of the nozzle and flows out from the outlet so that it is radially spread out and guided to an inner surface of the cylindrical portion of the vessel by the bevel; the filling valve being configured to open the plug when the seal member abuts against the vessel, characterized in that the bevel is extended below the outlet of the small-diameter shell segment of the nozzle and being configured to be positioned inside the cylindrical portion of the vessel while the top end of the bevel is about at the same level with the top end of the cylindrical portion of the vessel.