FIELD JOINT ARRANGEMENT FOR A PIPELINE AND PROTECTING METHOD THEREOF

摘要

A method of protecting a field joint (20) of a pipeline, where chamfered edges (22) of thermally-insulating parent coatings (14) on conjoined pipe lengths are in mutual opposition about a longitudinally-extending gap. The method comprises manufacturing an hourglass-shaped inner layer (8) around the pipe lengths, which layer may be moulded. The inner layer extends longitudinally along the gap between the chamfered edges (22) and at least partially overlies the chamfered edges (22). A thermally-insulating solid insert (54) is assembled from two or more parts to lie in the gap surrounding the inner layer (8), and pressure is applied radially inwardly from the insert (54) to the inner layer (8). An outer layer (78) of molten material is manufactured around the insert (54) to form a watertight barrier and to form one or more melted interfaces with the inner layer (8). Corresponding field joint arrangements are also disclosed.