Corrosion management

System reliability is of the utmost importance to water suppliers and their customers. However, corrosion problems can vary greatly within a single system because many variables affect corrosion, for example, pipe material, pipe age, pipe wall thickness, water additives, corrosion inhibitor treatment, soil chemistry, soil moisture content and/or local groundwater level, and stray currents [2]. Table 8.2 summarizes some of the physical, environmental, and operational factors that can affect the deterioration rate of water distribution systems and lead to their failrue [4]. 

Pipe material Pipes made from different materials fail in different ways 

Pipe wall thickness Corrosion will penetrate thinner walled pipe more quickly 

Pipe age Effects of pipe d radation become more apparent over time 

Pipe vintage Pipes made at a particular time and place may be more vulnerable to failure 

Example 3 A plant storage tank requires either (i) replacement to last 25 yr with no maintenance at a cost of 690 000 or (ii) a coating system with maintenance cost of 10% of installation costs, tax rate of 48%, interest rate of 10% and straight-line depreciation. 

According to Trethewey and Chamberlain5 corrosion management is defined to include people along with corrosion control which concerns with the materials used in a particular environment. The corrosion related failure may be due to (i) primary corrosion mechanism and/or (ii) secondary corrosion mechanism as shown below  

Personnel contributions such as producers, designers, manufacturers, users, monitors unforeseen changes in environmental conditions such as pH, oxygen, temperature, flow-rate, biological content 

The secondary corrosion mechanism involves the contributions of people in different ways and the people factor should be rated as high in corrosion management. The various 

As seen from the foregoing discussion the contribution of people to the failure of system is important and can be introduced into the total probability of corrosion failure as  

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It is conceivable that most of the tasks performed by humans may be replaced by computers in the future, but the role of people in corrosion management will not be diminished in spite of the technical advances being made. 

Corrosion economics and corrosion management forms the theme of the fifth chapter. Discounted cash flow calculations, depreciation, the declining balance method, double declining method, modified accelerated cost recovery system and present worth calculation procedures are given, together with examples. In the second part, corrosion management, including the people factor in corrosion failure is briefly presented. Some of the expert systems presently available in the literature are briefly discussed. 

B. Bazzoni, L Lazzari, Potential monitoring in presence of stray currents . Corrosion Management, 1995, 6, 9 12. 

Advance design practices for better corrosion management... 

The total cost of corrosion in the United States has been estimated by (i) adding the costs of corrosion control methods and services and (ii) estimating the total cost by extrapolating the corrosion costs of representative indusdial sectors to the entire US economy. The latter method incorporates all the costs that the first method is likely to miss such as the cost of corrosion management, the cost of direct services related to the owner/operator, and the cost of loss of the capital because of corrosion. 

B.F.M. Pots, R.C. John, I.J. Rippon, M.J.J. Simon Thomas, S.D. Kapusta, M.M. Girgis, T. Whitham. Improvements on de Waard-Milliams corrosion prediction and applications to corrosion management. Paper No. 02235, Corrosion 2002, NACE, Houston, TX, 2002. 

R. Javaherdashti. MIC myths Avoiding common pitfalls in the practice of hydrotesting and likelihood of microbial induced corrosion. Corrosion Management, January-February 2009. 

R. Javaherdashti, Managing corrosion by Corrosion Management A guide for industry managers, Corrosion Reviews, Vol. 21, No. 4, pp. 311-325, 2003. 

J.C. Earthman, W. Dang. Alternating magnetic field treatment of service water to control pitting induced by sulphate reducing bacteria. Corrosion Management, No. 96, pp. 11-14, 2010. 

Special reqnirements to carry ont the corrosion management program... 

Energy Institute, Guidance for Corrosion Management in Oil arul Gas Production and Processing, Energy Institute, 2003. 

HSE (2001), Review of corrosion management for offshore oil and gas processing. Available at http // www.hse.gov.uk/research/otopdf/2001/oto01044.pdf. Accessed November 8, 2011. 

An inspection plan (or written scheme of examination [WSE]) endorsed by the inspection and corrosion management services team/independent competent person that contains... 

Update of system corrosion management strategies where appropriate... 

Corrosion management is cross-functional in any organization, and various roles in the corrosion management system are undertaken by a variety of individuals and groups in different departments and their contracted bodies. 

Consideration of the above factors are vital for management of complex multidisciplinary areas of corrosion management, which involves both specialists (e.g corrosion, metallurgist, chemical treatment specialist, inspection), and nonspecialists such as those in plant operations and maintenance. 

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