Patent ID: 7748463

Claim:
A cementing valve for carrying out cementing operations in a wellbore comprising a casing, the cementing valve comprising: an inner sliding sleeve which in a closed position covers a number of openings through an outer pipe surrounding the inner sliding sleeve, and in an open position, the inner sliding sleeve uncovers the openings, the sliding sleeve comprising an actuating means requiring a predetermined force for being actuated from both the closed position to the open position and from the open position to the closed position, and engaging means being arranged on the inside of the sliding sleeve for being engaged by a well running tool comprising a corresponding gripping means; and at least one shear pin configured such that a predetermined force is necessary to overcome the shear resistance of the shear pin, wherein the sliding sleeve is arranged so as to move further past the shear pin when the shear pin breaks until the actuating means engages a first groove, and wherein the at least one shear pin, regardless of whether or not the shear pin has been cut, is arranged to prevent the sliding sleeve from rotating relative to the outer pipe, the shear pin being shaped to run in an axially extending slot in the sliding sleeve and being radially fixed in the outer pipe.