L51681 Repair of Pipelines by Direct Deposition of Weld Metal

The research in this document is aimed at establishing the feasibility of repairing defects, especially corrosion-caused metal loss, by direct deposition of weld metal in pressurized pipelines without removing them from service. While this might seem inherently dangerous, past experience with "puddle welds" in corrosion pits and with repair and hot tap welding on relatively thin pipe materials suggests that it can be done safely.