Field joint coating for steel pipe three layers polyolefin coated. Case study of application in Western Desert Gas Development Project - Egypt

The anticorrosion coated steel pipelines have shown a weak point at weld field joint in the past. The coating does not have the same performance of the pipes coated in plant and present failures during the exercise. The coating of field joint is generally performed in more critical conditions and often also with different materials and processes compared to the coating done in the plant and for this reason there are inferior and vulnerable characteristics which compromise the integrity of the overall pipeline. In our opinion, for three layer polyolefin coated steel pipes, the most dependable and acceptable cost coating, it is imperative to find the right technical and economical solution for field joint coating in order to not risk making the excellent coating of pipe also pointless. The best solution in the field joint coating is probably to use the same materials and the same technology giving the same performance to the final joint coating obtained with plant coating. The tape application in W.D.G.D. project is a step in this direction.