A combined lab and field program has been performed to study the external corrosion behaviour of buried linepipe. The overall aim of the project was to attempt to correlate pipe damage with measurable soil properties, in particular the redox potential as measured by buried soil probes. The lab component of the project involved the measurement of weight-loss corrosion rates in three types of soil, under saturated and as-received moisture conditions, and under permanently aerobic, permanently anaerobic or cyclic anaerobic/aerobic redox conditions. The soil conditions and coupon corrosion potentials...
A combined lab and field program has been performed to study the external corrosion behaviour of buried linepipe. The overall aim of the project was to attempt to correlate pipe damage with measurable soil properties, in particular the redox potential as measured by buried soil probes. The lab component of the project involved the measurement of weight-loss corrosion rates in three types of soil, under saturated and as-received moisture conditions, and under permanently aerobic, permanently anaerobic or cyclic anaerobic/aerobic redox conditions. The soil conditions and coupon corrosion potentials were monitored during the course of the tests. In the field component of the study, pipe-depth soil properties were monitored using permanent NOVAProbes to measure the redox potential, soil resistivity, pH and temperature. Daily readings were taken at some locations with the aid of a custom-designed datalogger. Corrosion information was obtained from buried weight-loss or electrochemical coupons, from pipe excavations or from data from repeat in-line inspection runs.