An Electrical Resistance Method of Corrosion Monitoring In Refinery Equipment

A corrosion test system based on the electrical resistance method permits continuous monitoring of corrosion rates in refinery equipment without interrupting normal operations. Corrosion decreases the cross-section, and consequently the electrical conductivity, of a metal specimen exposed to refinery fluids at high temperatures and inaccessible locations. From the decrease in conductivity, or increase in resistance, the amount of corrosion which occurs between measurements can be determined. The system has been used successfully under all conditions of temperature and pressure encountered in a refinery. It has measured corrosion rates in vapor and liquid phases, with both oil and aqueous media. With the aid of the corrosion probe, corrosion rates in operating refinery equipment have been determined quantitatively in a few hours’ time, as compared with months required for coupon measurements, water analyses, and unit inspections. Refinery corrosion inhibitors have been compared rapidly in actual use. Effects of changes in unit operating procedures upon corrosion rates have been observed shortly after the changes were made. Sensitive locations where corrosion is expected have been monitored frequently. 2.2.1