A length compensator for pipelines, preferably plastic pipelines, containing two connecting components, preferably made from plastic, a compensating element made from an elastic material, preferably a thermoplastic elastomer (TPE), and a supporting pipe, wherein the compensating element is arranged between the two connecting components and the compensating element ends are connected to the connecting components, wherein the outer lateral surface of the compensating element is suitably encompassed by the inner lateral surface of the supporting pipe around its entire circumference, wherein the supporting pipe has a circular cross-sectional area and the compensating element expands and contracts exclusively in the axial direction.