Pipeline corrosion prevention—cased crossings

A SOURCE of concern to the pipeline corrosion engineer is the sleeved crossing. Should this become partially or totally shorted to the carrier pipeline a depression in the attenuation curve of cathodic protection will arise and protection on the carrier pipe will be reduced or be non‐existent for a short length. The fault is not difficult to find, the remedy can be costly. As in all corrosion matters the prevention of a particular problem commences at the design stage on the drawing board.