Prefabricated insulated pipe sections are constructed of an inner pipe surrounded by a concentrically-positioned outer pipe. End portions of the inner and outer pipes are joined with bellow members so that an annular space is defined. A portion of the inner pipe is wrapped with layers of insulation material with inert insulating granules positioned between the layers. The annular space is partially evacuated to below atmospheric pressure. Multiple pipe sections may be joined by their inner pipes through brazing or other known methods. The joints and neighboring bellow members on abutting pipe sections are covered by vacuum sleeves that are sealed and provide a vacuum tight joint.
