the shear pin breaks until the actuating unit engage a groove application_number US 8767007 A description fig1 a b shows an embodiment of the present invention comprising a cementing valve 1 joined between casing sections 2 the cementing valve 1 includes a sliding sleeve 3 a number of openings 4 through an outer pipe 5 of the cementing valve 1 the openings 4 are used for pumping cement from an inside located tool to the outside of pipe 2 an actuating means 6 e g in the form of a pre tensioned leaf spring or another spring means comprising a pin 7 or another means of engagement is arranged so as to be able to engage grooves 9 10 11 provided on the outside of the sliding sleeve 3 the grooves 11 10 9 correspond to an open closed and permanently closed and locked position respectively in fig1 b the actuating means 6 is located in the closed position in which the pin 7 engages groove 10 each of the grooves 9 10 and 11 has edges shoulders 9 a 10 a b and 11 a having a distinct slope the slope influences the force needed to shift the sliding sleeve from one position to another in order to shift the sliding sleeve 3 from the closed position in which the actuating means 6 engages groove.