Ensuring the Integrity of Critical Pipe‐to‐Cathodic

Achieving cathodic protection (CP) on buried or immersed pipelines requires the connection of copper conductors to carbon steel. Connections are needed both for the primary current drain cables; and for the various test leads and bonds that enable the CP system to be monitored and managed. These connections are all too often made in less than ideal conditions (in the field or offshore), and with the urgency needed to keep pace with the pipeline installation schedule. Moreover, once made, they will be permanently out of sight; yet must remain intact throughout the entire life of the pipeline. This paper recaps the history of the available cable connection techniques in common use: thermite welding pin brazing and conducting adhesives; and compares their relative merits. The comparison assesses their practicability, including health and safety, cost and the reliability of the resulting connections. In addition, the effects of the thermal processes on the metallurgical condition of the pipe wall are reviewed in the light of micro‐hardness measurements. The metallurgical implications of using thermal connection techniques on high strength (>700 MPa) thin walled lines, of the type currently under review for future projects, are considered.