Managing Pressure Equipment Aging in Plants with Major Accident Hazard: A Methodology Satisfying the Requirements of the European Directive 2012/18/UE Seveso III

Attention to be paid to the aging of industrial facilities has been growing in the last ten years, both by public authorities and industrial executives. Many process plants, operating in Europe, have reached or exceeded their project nominal life and the safe management of aging is an urgent question. Failures, due to aged chemical process plants, cause the release of hazardous materials with severe consequences for people and workers. To counteract this phenomenon, plant operators carry out many technical activities, including non-destructive controls on piping and vessels, by adopting sophisticated methods (e.g. Risk Based Inspection RBI). The European Directive 2012/18/UE (Seveso III) for the control of Major Accident Hazard (MAH) introduced a few requirements for the safe aging of critical equipment, which must be verified during mandatory audits. The aim of this work is to present a synthetic methodology that can be useful for both Seveso auditors and industrial managers for evaluating the adequacy of the measures to control the aging of critical equipment. To achieve a synthetic assessment of the adequacy of the aging management programs, a compensated index method has been developed, which is a simple and easyto-use tool. The use of an index method inevitably introduces a degree of uncertainty. However, if it is compared to other qualitative methods, such a tool offers the advantage of a major clarity in the assessment process. This paper discusses a practical application of the method within inspection programs, as required by the art. 27 of Seveso III Directive.