Abstract: A conduit especially suitable for carrying high temperature fluids is disclosed herein and includes an outer casing, a concentric inner core and an intermediate concentric layer of insulation material. The conduit also includes what may be referred to as a pressure relief valve located through the outer casing of the conduit and extending into the concentric layer of insulation material. In the event that the fluid finds its way into this layer of insulation material and in the event it expands, the pressure relief valve provides a readily available passage to the ambient surroundings for the expanding fluid.