A connecting system is accordingly provided for a line tube, which can be pivoted about a rotation axis of a solar-thermal installation, which line tube is filled with a carrier fluid, wherein the line tube extends between two ends and is connected, for transportation of the carrier fluid, at a first end via a flexible tube connection to a fixed-position fixed line and at its second end via at least one connection means to a further line tube. According to the invention, the line tube is supported such that the flexible tube connection experiences only forces acting at right angles to the rotation axis, and the connection means experiences only forces acting parallel to the rotation axis.