PSI - Issue 31

J. Lukács et al. / Procedia Structural Integrity 31 (2021) 51–57 J. Lukács et al. / Structural Integrity Procedia 00 (2019) 000–000

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which all stakeholders can learn (EEA, 2010). Furthermore, accidents produce external pressures on companies leading to new regulations and renegotiation of enforcement of rules and regulations (Lindoe et al., 2011). Nomenclature d f depth of the artificial flaw (longitudinal or circumferential gouge) d h diameter of the artificial through hole D external or outside diameter of the pipe l f length of the artificial flaw (longitudinal or circumferential gouge) N/A not applicable p max minimum internal pressure during the fatigue test p min maximum internal pressure during the fatigue test PS Pipeline Section t wall thickness of the steel pipe Wi designation of the composite Wrap system (i = 1, 2, 3, 4) WW wrap system was not applied (Without Wrap) The brochure (IACG-ICA, 2020) contains an overview of different international organizations and groups working on prevention, preparedness and response to chemical and industrial accidents. A summary of key tools and methodologies developed by the organizations were summarized, in accordance with the timeline of the accidents. The purpose of the Major Accident Reporting System (MARS, later renamed eMARS after going online) is to facilitate exchange of lessons learned from accidents and near misses involving dangerous substances in order to improve chemical accident prevention and mitigation of potential consequences (EC). There are other accident report sites, e.g. The Central Reporting and Evaluation Office for Major Accidents and Incidents in Process Engineering Facilities (ZEMA), The Japanese Failure Knowledge Database (ASF) in order to share the experiences and observations worldwide. The safety and reliability of a structure or a technical system is closely related to its integrity (Lukács et al., 2012), and the different types (e.g. bridges (Helmerich, 2005), ships (Fricke, 2017), vehicles (Keeler et al. (Eds.), 2017), offshore platforms (Christou and Konstantinidou, 2012), other steel structures (Božić et al., 2018; Lukács, 2019), machine elements (Pastorcic et al., 2019; Vukelić et al., 2020)and transporting pipelines (Penspen, 2016)) exhibit characteristics. Material quality, construction, applied manufacturing technology and the inhomogeneities affect both the safety and reliability, and the integrity. Natural gas nowadays is one of the most important energy sources for the customers. Natural gas has advantageous and favorable environmental and physical properties and due to these properties, it is more and more dominant among the applicable energy sources (IEA, 2019; IEA, 2020). The share of natural gas in the applied energy sources depends on the geographical and geopolitical conditions as well as the resource supply of the different countries (Colombo et al. (Eds.), 2016). In Hungary, the FGSZ Natural Gas Transmission Closed Company Limited (abbreviated FGSZ Ltd.) is responsible for transporting the natural gas from the import, gas storage, and domestic production entry points to the customers. FGSZ Ltd. is the operator of a fully integrated natural gas transmission system which contains inlet points, compressor stations (6 items), pipeline nods, high-pressure pipelines (5782 km length) and gas delivery stations. The gas is fed into FGSZ Ltd.’s high-pressure pipeline system through the gas inlet points, supplied from import sources, domestic gas fields and domestic gas storage facilities. The whole system consists of only steel pipelines, the operating pressure range is 40-75 bar (4-7.5 MPa) and the typical operating pressure is 63 bar (6.3 MPa). The Hungarian natural gas transmission system is connected to almost all the natural gas transmission systems of the neighboring countries (Chován, 2011; FGSZ, 2016). Generally, steel pipelines are commonly used for transportation over long distance due to its cost-effective particularity (IEA, 2013) and good mechanical properties. One of the disadvantages of the steel material is its low corrosion resistance (Ossai et al, 2015; Muthanna et al., 2019). Gas transporting pipelines operate often in a hard circumstances (static and cyclic loads, environment, temperature, long-term operation) which can lead to deformations (Kelil et al., 2019), through-wall corrosion defects, causing leakage (Kumar, 2016), or cracks (Medjdoub, 2018). Traditionally, the pipelines with dangerous corrosion defects have to either been repaired using different techniques or replaced by new ones.