Safety valve for a hydraulic system comprising oil,, said safety valve comprising: - an inlet; - an outlet; and - a channel; wherein, for the safety valve, a maximum operating flow rate value Q m of the oil is predefined, and wherein the channel is suitable to guarantee an operating oil flow from the inlet to the outlet, the operating oil flow having a flow rate comprised between zero and the maximum operating flow rate value Q m; wherein the safety valve further comprises emergency blocking means positioned along the channel; and wherein the emergency blocking means are adapted to be actuated by an oil flow rate along the channel which exceeds the maximum operating flow rate Q m and are suitable for closing the channel; wherein the emergency blocking means comprise a shutter adapted to move between an open position and a closed position of the channel, and a spring for which a preload value is predetermined, and wherein the preload value of the spring can be adjusted during the operating life of the safety valve; characterized in that the channel comprises a main channel and an auxiliary channel, and in that the emergency blocking means are adapted to be actuated by an oil flow rate along the auxiliary channel. - an inlet; - an outlet; and - a channel; wherein, for the safety valve, a maximum operating flow rate value Q m of the oil is predefined, and wherein the channel is suitable to guarantee an operating oil flow from the inlet to the outlet, the operating oil flow having a flow rate comprised between zero and the maximum operating flow rate value Q m; wherein the safety valve further comprises emergency blocking means positioned along the channel; and wherein the emergency blocking means are adapted to be actuated by an oil flow rate along the channel which exceeds the maximum operating flow rate Q m and are suitable for closing the channel; wherein the emergency blocking means comprise a shutter adapted to move between an open position and a closed position of the channel, and a spring for which a preload value is predetermined, and wherein the preload value of the spring can be adjusted during the operating life of the safety valve; characterized in that the channel comprises a main channel and an auxiliary channel, and in that the emergency blocking means are adapted to be actuated by an oil flow rate along the auxiliary channel. wherein, for the safety valve, a maximum operating flow rate value Q m of the oil is predefined, and wherein the channel is suitable to guarantee an operating oil flow from the inlet to the outlet, the operating oil flow having a flow rate comprised between zero and the maximum operating flow rate value Q m; wherein the safety valve further comprises emergency blocking means positioned along the channel; and wherein the emergency blocking means are adapted to be actuated by an oil flow rate along the channel which exceeds the maximum operating flow rate Q m and are suitable for closing the channel; wherein the emergency blocking means comprise a shutter adapted to move between an open position and a closed position of the channel, and a spring for which a preload value is predetermined, and wherein the preload value of the spring can be adjusted during the operating life of the safety valve; characterized in that the channel comprises a main channel and an auxiliary channel, and in that the emergency blocking means are adapted to be actuated by an oil flow rate along the auxiliary channel.