A solid-state welding process used to join two pipes by heating them to a high temperature and applying a high electric current to create a localized, intense burst of heat called a "flash." The flash quickly melts the ends of the pipes, which are then forged together under pressure to form a solid weldLocalized coalescence of metals produced by heating the materials to the welding temperature, with or without the application of pressure, or by the application… jointA single section (also pipe spool) of pipe that is circumferentially welded to form a pipeline..