Soldagem de reparo em dutos de transporte pressurizados e em operação

Abstract

The pipeline transportation has been consolidated as an efficient and low operating cost method for transporting fluids. Accordingly, in recent years there was a considerable increase in installed pipeline network in Brazil. In this context, more maintenance activities and expansion of the installations are demanded. To this end, the use of the in-service welding process becomes essential to reduce costs and environmental impact. This work provides information about pipeline inspection techniques, the main types of defects that can degrade the integrity of a pipeline. The defects are gathered in three main groups (geometric deformation, metal loss and cracking). The work also informs the welding repair methods that can be applied to correct each defect type with emphasis on the application of steel sleeves, metal deposition, hot tapping and patches. It also addresses the concerns regarding to in-service welding on pipelines (burn through and hydrogen induced cracking), and measures to mitigate the risk of these problems. It discusses the possibility of applying automatic welding processes for maintenance in-service pipelines and how this development is required.