PIPE -JOINING METHOD AND SYSTEM FOR PRODUCING UNDERWATER PIPELINES, AND UNDERWATER-PIPELINE-LAYING VESSEL COMPRISING SUCH A SYSTEM

摘要

A method of joining pipes (3) to produce an underwater pipeline (2) on a firing line (8) includes supplying the firing line (8) with pipes (3) having previously roughened end portions (15); welding the end portions (15) of adjacent pipes (3) to form cutbacks (22), each of which is defined by two end portions (15), and by an annular weld bead (21) between the two end portions (15); cleaning, by cryogenic blasting, the outer surface of each cutback (22); and forming a protective joint coating (23, 24, 25) about each cutback (22).