A linear sliding hydraulic valve with emergency actuation, comprising: • a valve body including at least one inlet and at least one outlet ; • a sliding member inside the valve body to allow or prevent the passage of a fluid operating in inlet and outlet ; • a first and second primary actuators arranged at axially opposite sides of said valve body for the actuation under standard operative conditions of said sliding member in said valve body ; • a secondary actuator for a secondary actuation of said sliding member in said valve body , wherein said secondary actuator is interposed between said valve body and said first primary actuator or said secondary actuator , and wherein said secondary actuator comprises: • a secondary actuator body ; • an axial member slidably driven in said secondary actuator body and interposed between the sliding member and the primary actuator , to transmit the action exerted by said primary actuator to the sliding member ; and • a mechanical actuation configured to be accessible from the outside of the secondary actuator body , to translate said axial member from and to an actuating position of the sliding member independently of the actuation of the primary actuator , wherein said mechanical actuation comprises a shaped movable body and a motion conversion mechanism to convert a motion of said shaped movable body into a translational motion of the axial member • characterized in that the motion of said shaped movable body converted by said motion conversion mechanism comprises a rotational movement of said shaped movable body about an axis (T) oriented according to a substantially radial direction with respect to said axial member or a translational movement along said axis oriented according to a substantially radial direction with respect to said axial member . • a valve body including at least one inlet and at least one outlet ; • a sliding member inside the valve body to allow or prevent the passage of a fluid operating in inlet and outlet ; • a first and second primary actuators arranged at axially opposite sides of said valve body for the actuation under standard operative conditions of said sliding member in said valve body ; • a secondary actuator for a secondary actuation of said sliding member in said valve body , • a secondary actuator body ; • an axial member slidably driven in said secondary actuator body and interposed between the sliding member and the primary actuator , to transmit the action exerted by said primary actuator to the sliding member ; and • a mechanical actuation configured to be accessible from the outside of the secondary actuator body , to translate said axial member from and to an actuating position of the sliding member independently of the actuation of the primary actuator , wherein said mechanical actuation comprises a shaped movable body and a motion conversion mechanism to convert a motion of said shaped movable body into a translational motion of the axial member • characterized in that the motion of said shaped movable body converted by said motion conversion mechanism comprises a rotational movement of said shaped movable body about an axis (T) oriented according to a substantially radial direction with respect to said axial member or a translational movement along said axis oriented according to a substantially radial direction with respect to said axial member . <EOS>