Conduit insulates and warms realized by double SECTIONS envelope and laying conduit PROCESS

A portion (1) of a pipe for transporting hydrocarbons, said portion being composed of at least a jacket comprising an outer casing (5) and an inner shell (6) between which is arranged a space ring comprising a thermally insulating material (7), permitting the maintenance or increase in temperature, said section comprising at least one heating circuit disposed in said annular space and a base (8) for connection to a connecting plug to a cable external power supply, the base (8) closing a passage (10) access to said annular space, the heating circuit electrically powered by the base forming a closed electrical circuit heating the single section. The invention also relates to the duct comprising such sections fed in parallel by the external supply cable, and a laying process of this duct, the installation being made of S or J