Decay of man’s handiwork prevails the world over. It is particularly rapid in underground engineering structures where destructive forces and elements often work undetected until failure occurs. When preventive measures are omitted or cease, decay proceeds apace.
On buried steel pipe lines, decay takes the form of corrosion which is caused principally by action of soil chemicals that combine with the pipe metal in the presence of moisture. The action is. electrochemical, and it sets up electrical forces that can be detected by electrical instruments without excavation of the pipe. The analysis of instrument readings shows the areas of active corrosion and the degree of severity. Similar electrical surveys along the routes of proposed new lines permit limited prediction of the degree of soil action to be expected.
Corrosion of buried pipe lines can be retarded by suitable protective measures. Protective paints and coatings were tried at first, with but...
