Abstract: A gripping mechanism for gripping a retraction cone attached to a workpiece includes an outer shroud formed of an outer tubular part and an outer funnel-shaped part; a gripping device which is axially movable within the outer shroud, the gripping device including a tubular sleeve which has wings axially movable with axial slots in the outer tubular part and a plurality of finger elements with hook-shaped ends attached to the wings; an operating device which includes an independently rotatable sleeve threadingly engaged in the tubular sleeve and an inner funnel which is attached to the outer funnel-shaped part and which includes control slots for the finger elements; and a motor for rotating the rotatable sleeve so as to either axially move the tubular sleeve within the outer shroud such that the finger elements move towards the retraction cone for gripping the retraction cone or, after having gripped the retraction cone, in an opposite direction to position the retraction cone within the inner funnel.

Abstract: The present invention relates to a method for replacing an insert unit included in an insert valve assembly belonging to a subsea production system for gas and oil. In carrying out the method, a manipulator (1) is brought by means of a sheave (2), a hoisting cable (3) and guide wires (4, 5) down to a predetermined location on the bottom of the sea. The manipulator comprises a telescopic arm (15, 16) which is then moved towards and fixed by means of a hook (20) and a lug (21) to a valve tree (17) which supports a valve (22), the insert unit (26) of which is to be unscrewed from the respective valve housing and be replaced. A carriage (18) located in the manipulator and comprising retracting, aligning and fixing devices (32, 33, 34) is brought with the aid of the telescopic arm and a rail, located on the top side of the carriage, towards the valve tree and is fixed to retraction cones (35, 36, 37) mounted on the valve tree.