Abstract: The invention is an underwater LNG pipeline system in modular sections wherein multiple LNG pipelines utilizing expansion joints to compensate for contraction are connected together by braces to form an integral frame, and including pressure vessels enclosing the expansion joints to permit access to the expansion joints for inspection or maintenance. In a second embodiment, the frame is a separate elongate space frame connected to the pipeline and the pressure vessels. In a third embodiment, the pipelines are INVAR steel and no expansion joints or pressure vessels are included.

Abstract: An underwater cryogenic pipeline system comprising an insulated underwater pipeline in an integral open frame is disclosed. The pipeline is anchored to the frame at a plurality of spaced apart locations. Bellows-type expansion joints between the pipe anchors compensate for contraction in the pipeline. The frame, which is anchored to the soil at at least one location, resists axial forces in the system and wave and current loadings. The system is preferably fabricated in modules and assembled on site.

Abstract: A pipeline system which is capable of withstanding a range of extreme temperatures is disclosed. A pipe is surrounded by a vapor barrier which has a corrugated surface facing the pipe. The amplitude of the corrugations changes, absorbing the stress imposed by extreme temperatures, especially those at which liquefied natural gas is carried.

Abstract: A double-walled, hermetically sealed structure with the cavity between the walls containing a polyurethane foam blown with a fluorinated hydrocarbon. During fabrication the cavity is evacuated to remove air and water vapor and then refilled with a fluorinated hydrocarbon.

Abstract: A pipeline system designed for withstanding elevated levels of pressure from external sources. Pressurized gas is introduced into an annulus between an outer pipe jacket and insulation material, which in turn surrounds a pipe, to supply structural support.