A torque isolating valve actuator comprising: an actuator housing ; a nut housing disposed within the torque isolation valve actuator having an actuator end and a stem end; a planetary roller screw comprising rollers within the nut housing ; a screw shaft aligned axially through the rollers in the nut housing wherein the nut housing is configured to move along the screw shaft ; wherein the rollers are configured to engage the threads on the screw shaft which is positioned in the center of the rollers ; characterised in that : a non-rising hollow stem is coupled to the stem end of the nut housing and configured to pass the screw shaft as the nut housing moves along the screw shaft ; the nut housing comprises guide channels positioned on the outside of the nut housing ; and wherein the valve actuator further comprises rods disposed parallel the screw shaft within the actuator housing and connected to the actuator housing and positioned outside the nut housing and passing through the guide channels; wherein the guide channels and rods are configured to prevent the nut housing from rotating as the actuator actuates; and wherein the nut housing and rods are configured to shield the stem from the transfer of a torque force caused by the rotation of the planetary roller screw. an actuator housing ; a nut housing disposed within the torque isolation valve actuator having an actuator end and a stem end; a planetary roller screw comprising rollers within the nut housing ; a screw shaft aligned axially through the rollers in the nut housing wherein the nut housing is configured to move along the screw shaft ; wherein the rollers are configured to engage the threads on the screw shaft which is positioned in the center of the rollers ; characterised in that : a non-rising hollow stem is coupled to the stem end of the nut housing and configured to pass the screw shaft as the nut housing moves along the screw shaft ; the nut housing comprises guide channels positioned on the outside of the nut housing ; and wherein the valve actuator further comprises rods disposed parallel the screw shaft within the actuator housing and connected to the actuator housing and positioned outside the nut housing and passing through the guide channels; wherein the guide channels and rods are configured to prevent the nut housing from rotating as the actuator actuates; and wherein the nut housing and rods are configured to shield the stem from the transfer of a torque force caused by the rotation of the planetary roller screw. a non-rising hollow stem is coupled to the stem end of the nut housing and configured to pass the screw shaft as the nut housing moves along the screw shaft ; the nut housing comprises guide channels positioned on the outside of the nut housing ; and wherein the valve actuator further comprises rods disposed parallel the screw shaft within the actuator housing and connected to the actuator housing and positioned outside the nut housing and passing through the guide channels; wherein the guide channels and rods are configured to prevent the nut housing from rotating as the actuator actuates; and wherein the nut housing and rods are configured to shield the stem from the transfer of a torque force caused by the rotation of the planetary roller screw. <EOS>