Patent ID: 8393121

Claim:
A rigid and thermally stable conduit having an inner wall defining an inner space through which a single pipe or a single bundle of pipes extends, each pipe being a, relatively, thermally weakenable pipe having an outer wall, wherein the inner space includes a system comprising at least a thermally expandable device which includes at least one component having a non-linear thermal expansion characteristic, wherein the device has surfaces which start melting at a temperature under a lowest end of a temperature-range in which the device displays a non-linear expansion characteristic which surfaces then form a sticky material, the device being made of a vulcanizable compound having a predetermined shape, the device being positioned concentrically relative to the inner space for concentrically surrounding the pipe or the single bundle of pipes, and such that: a gas-entrance space is located between the device and the inner wall of the conduit, between the outer wall of the pipe or outer walls of the single bundle of pipes and the device, or through the device and is configured to allow hot gas to enter the gas-entrance space whereby the sticky material is formed at the surfaces of the device and the device is firmly fixed within the conduit before onset of the non-linear thermal expansion of the device.