On-line corrosion monitoring of chemical process plants

In a continuous chemical process plant the useful service life of equipment/component is the factor of design, operation, fabrication and maintenance. In order to know the effect of the deficiencies in these areas, online corrosion monitoring can be an important approach to identify the causative factors. The traditional online corrosion monitoring techniques are based on the periodic visual inspection, the exposure of wt. loss coupons and the use of electrical resistance and linear polarization resistance monitoring. These techniques are useful but inadequate for online evaluation or control in chemcial process plants. To identify the specific process conditions, which are responsible for the corrosion episodes, advanced electrochemcial techniques based on a.c. perturbative and non-perturbative circuity offer significant improvement over conventional approaches. The multi-system monitor comprising of these techniques may be proved very useful to maximise the reliability and availability of the plant. The various techniques and support of data acquisitions, analysis and displays in the light of corrosion failure manifestation is discussed.