External Corrosion of Piping

Buried pipelines are subject to external corrosion from ground water and highly conductive soils. The corrosiveness of soils is often estimated based on soil resistivity measurement. The measurement is made with the Wenner four-pin method, which is used in conjunction with a Vibroground(1 and a Miller U 10-pin conductor set to determine the average electrical resistivities. A general relationship between corrosion and soil resistivity is as follows [Pg.104]

Maximum pit depths as a function of time can be estimated by using the following equation [Pg.105]

The most economical way to prevent external corrosion of underground piping is to coat the pipe and use cathodic protection. [Pg.105]

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