A coupling system for tubing and pipelines, comprising - a plug nipple; - a coupling body, with one or more latching elements, with the plug nipple being fixable to the coupling body by means of the one or more latching elements; as well as with - a locking sleeve being movably held at the coupling body by a forced guidance, by way of which forced guidance a) the locking sleeve is transferable in relation to the coupling body into a first relative position in which the plug nipple is affixed to the coupling body by the one or more latching elements; and by way of which forced guidance b) the locking sleeve is transferable in relation to the coupling body into a second relative position in which the fixation between the one or more latching elements and the plug nipple is undone; wherein the coupling system comprises at least one spring that is associated with the coupling body and the locking sleeve and that impinges the locking sleeve in relation to the coupling body with axial positioning force and with a torque for an independent change from the second relative position into the first relative position, characterised in that - the forced guidance is formed by an s-shaped groove in the locking sleeve, with a pin that is in a fixed connection to the coupling body engaging through said s-shaped groove, wherein - the s-shaped groove has at least two legs (30, 32), with the guiding directions for the pin of each of the two legs running parallel to the longitudinal axis of the locking sleeve. - a plug nipple; - a coupling body, with one or more latching elements, with the plug nipple being fixable to the coupling body by means of the one or more latching elements; as well as with - a locking sleeve being movably held at the coupling body by a forced guidance, by way of which forced guidance a) the locking sleeve is transferable in relation to the coupling body into a first relative position in which the plug nipple is affixed to the coupling body by the one or more latching elements; and by way of which forced guidance b) the locking sleeve is transferable in relation to the coupling body into a second relative position in which the fixation between the one or more latching elements and the plug nipple is undone; wherein the coupling system comprises at least one spring that is associated with the coupling body and the locking sleeve and that impinges the locking sleeve in relation to the coupling body with axial positioning force and with a torque for an independent change from the second relative position into the first relative position, characterised in that a) the locking sleeve is transferable in relation to the coupling body into a first relative position in which the plug nipple is affixed to the coupling body by the one or more latching elements; and by way of which forced guidance b) the locking sleeve is transferable in relation to the coupling body into a second relative position in which the fixation between the one or more latching elements and the plug nipple is undone; wherein - the forced guidance is formed by an s-shaped groove in the locking sleeve, with a pin that is in a fixed connection to the coupling body engaging through said s-shaped groove, wherein - the s-shaped groove has at least two legs (30, 32), with the guiding directions for the pin of each of the two legs running parallel to the longitudinal axis of the locking sleeve.