Patent attributes
A fluid conduit that is below grade or under water is separated from ambient water by a confined layer of liquid that may be largely undivided by solids. The separation distance between the liquid containment means and the piping or pipeline is such that the total heat transfer by natural convection and conduction from the piping or pipeline to the water containing environment is kept within limits thought necessary to adequately insulate the contents of the pipeline. A liquid may be pumped between the pipe and the means for containing the insulation so as to displace fluids from a pipeline or a heated liquid may be pumped through that space to warm the contents of the pipeline. If the insulating liquid also electrically insulates the pipe, then the pipe may be heated by passing a current directly through the pipe.
