This paper describes the Creep Amendments which will be implemented in EN 13445, the European Standard for Unfired Pressure Vessels, in 2007. It will address four topics: 1) Specifications for Materials and Weldments. 2) Specifications for Design By Formula and Damage Accumulation rules. 3) Specifications for Design By Analysis — Direct Route (Creep Rupture, Excessive Creep Strain, Creep and cyclic Fatigue Interaction). 4) Specifications for Inspection and Non-Destructive Testing (NDT).

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 easy-to-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.

Since 1989 ISPESL has emanated dispositions for pressure equipment designed to operate in the creep range according to time dependent mechanical properties. During the years, on the basis of the results of in-field examinations, a series of new provisions has been improved and sharpened the original procedure. During the last two years ISPESL has gone to revise and update the emanated regulations. Now a new entire legislation covers all the subjects and it is set as an advanced means of investigation for equipment working in the creep range: ISPESL technical procedure N. 48/2003. The elaborating of the legislation in matter has benefited from the previous experience, the indications of users and the European and international standards. The procedure is widely applied in Italian plants.

The Small Punch test is a miniaturized non-intrusive methodology that allows performing creep tests using very small specimens. It can be used for the residual lifetime assessment of in service components. In the last years, numerous applications of Small Punch Testing as well as related pre-normative work and Round Robin exercises have led to new insights which motivate a revision of the current Code of Practice for Small Punch Testing (CWA 15627, Dec. 2007) and/or its transfer in an EN norm. In this paper we present the state-of-art of the small punch technique: its performances, usefulness and critical aspects have been discussed and some examples have been reported. Some measurements carried out during the round-robin exercises have been reported: several testing laboratories are cooperating in a round-robin on a virgin P92 material. The tests are still in progress, so only preliminary data will be shown in this paper. A series of measurements performed during the pre-normative time will also be shown: a serviced (116,000 hours) ASME A213 T91 tube, installed in a petrochemical plant has been investigated. Small punch tests were performed and the residual life was then estimated by Omega Method. A microstructure characterization has been also reported. The results obtained encourage new efforts for material testing by SPT; sampling, however, was found as a critical step if the analyzed material may suffer from localized damage.

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