Sense and nonsense of service-life statistics

The technical service life of buried components remains restricted, irrespective of the material used, as a result of external mechanical influences and also due to chemical or electrochemical and physical interac-tions of the components with their surroundings. To assure the unimpaired functioning of such components, informationally valuable criteria are of great significance during operation for the assessment of the remain-ing service life and for planning rehabilitation projects. One possibility for this is provided by the evaluation of statistical data, which, however, inevitably involves uncertainties. Questions arise, in the case of steel compo-nents, as to the rationality or otherwise of such service-life statistics where additional provisions for the op-eration and maintenance of a piping system are implemented using the potentials of cathodic corrosion protection (CCP). The importance of cathodic corrosion protection in modern pipeline engineering practice, and the significance of this anticorrosion system for the pipeline service life and rehabilitation planning are ex-amined in this article using examples drawn from practice.