[pt] Verificação de Consistência com as Práticas Usuais da Indústria para Avaliação de Risco. A sociedade tem feito crescentes exigências quanto à redução de eventos com dutos, que resultem em danos à pessoa humana e ao meio ambiente. A competição de mercado exige dos operadores de dutos, confiabilidade e disponibilidade dos serviços de transferência e transporte de hidrocarbonetos, importante elo da cadeia logística da produção de petróleo. Este cenário leva, muitas vezes, os agentes regulamentadores a emitirem medidas prescritivas para a garantia da integridade dos dutos. Apesar disto e de muitos operadores excederem os requisitos prescritos, muitos acidentes com dutos tem ocorrido. Em resposta a este cenário desafiante, a indústria tem se organizado para sistematizar o gerenciamento da integridade de dutos baseando-se em risco. A norma API STD 1160 - Managing System Integrity for Hazardous Liquid Pipelines é de aplicação específica para dutos de hidrocarbonetos líquidos instalados em áreas de grandes conseqüências, definidas pela legislação norteamericana, porém não apresenta uma sistemática de aplicação simples e imediata. Iniciativas para indicar à indústria, metodologias simplificadas de avaliação de risco de modo a proporcionar aos operadores de dutos, ferramentas para a otimização dos recursos de inspeção com vistas à redução do risco, são bem recebidas e devem ser incentivadas. Neste trabalho é feita uma avaliação da metodologia de IBR para plantas industriais proposta no API 581 BRD, quanto a sua aplicabilidade a dutos. É verificada ainda a sua consistência com as práticas para avaliação de risco usadas pela indústria dutoviária, representadas neste estudo, pelo aplicativo comercial chamado IAP, Integrity Assessment Program. A metodologia do API 581 BRD foi aplicada à quatro oleodutos terrestres de uma unidade de Exploração & Produção, através dos métodos qualitativo, semi quantitativo e quantitativo de análise de risco para IBR e os resultados são discutidos. Observou-se a limitação do API 581 BRD para aplicação a oleodutos devido à falta de critérios para abordar alguns modos de falha que ocorrem em dutos e para tratar de conseqüências ambientais. Esta limitação decorre das diferenças fundamentais entre o modo de instalação de um duto e de um vaso de pressão. Mesmo assim foram avaliados programas de inspeção para os dutos estudados e os resultados alcançados foram considerados consistentes. Quanto ao software IAP, justamente por ser um aplicativo especialista, recomenda-se o seu desenvolvimento na direção da sistematização da busca de cenários mitigadores de risco otimizados em relação a custo. É proposta uma melhoria ainda mais desafiante, ou seja, a incorporação no algoritmo do IAP, do método do teorema de Bayes para se atualizar as expectativas do avaliador da integridade do duto sobre a evolução de um defeito sob observação, considerando-se a eficácia das técnicas de inspeção empregadas e o tempo decorrido entre uma inspeção e outra. Deste modo, se poderá avaliar diretamente programas de inspeção para dutos com o software IAP, usando- se uma metodologia simplificada similar à proposta no API 581 BRD. Recomenda-se para futuro estudo a aplicação do software em desenvolvimento para a norma API RP 580 a oleodutos com o objetivo de se verificar igualmente, sua metodologia quanto aos aspectos de adequação e simplicidade. / [en] An Evaluation of its Consistency to the Industry Common Practices for Risk Assessment. Society is increasingly demanding to industry actions aiming at reducing the occurrence of events with pipelines, which can result in injuries, fatalities and pollution. Market competition requires pipeline operators provide their clients with reliable and available transportation and transmission services, important links in the oil production supply chain. This scenario makes regulators to enact prescriptive measures in order to achieve higher levels regarding to pipeline integrity. Albeit these measures and the fact that sometimes pipeline operators exceed them, many accidents involving pipelines have been happening. In response to this challenging scenario, industry has been making efforts towards the systematization of integrity management considering risk. The standard API STD 1160 Managing System Integrity for Hazardous Liquid Pipelines was conceived specifically for liquid pipelines installed in high consequence areas, as defined by the North American legislation, but it doesnt contain an easy to apply and a simplified methodology. Initiatives aiming at providing the industry with simplified risk assessment methologies and tools for the optimization of inspection resources and risk reduction are welcome and should be stimulated. In this study its evaluated the applicability of the RBI methodology for processing plants and refineries, proposed in API 581 BRD, to pipelines. Its also verified the consistency of this methodology to the pipeline industry risk assessment practices, represented in this study by the commercial software IAP, Integrity Assessment Program. The API 581 BRD methodology was applied to four oil pipelines installed in an Exploration and Production business unit, using the qualitative, semi-quantitative and the quantitative approaches for risk assessment and RBI for optimizing inspection plans. The results are evaluated and discussed. Its observed limitations of API 581 BRD in regard to its application to pipelines as there are missing criteria for evaluating some pipeline typical failure modes and their respective environmental and financial consequences. These limitations result from the fundamental differences between the pipeline and pressure vessel installation ways. In spite of that, inspection plans for the pipelines studied were evaluated and the results obtained were considered consistent and satisfactory. Regarding the software IAP, mainly because its a specific program, its recommended its further development towards the implementation of a cost optimization algorithm for operators standard risk mitigation scenarios. Its also proposed a challenging improvement on the IAP, that is, the inclusion of the Bayes theorem methodology in its algorithm, aiming at updating the pipeline integrity evaluator expectations about the evolution of a defect taking into consideration the efficiency of the inspection techniques being used and the inspection frequency on that defect. With this provision it will be possible to evaluate inspection plans directly with IAP, using a simplified methodology, similar to that proposed in API 581 BRD. Its recommended for a future study, the application of the software which is presently being developed for the standard API RP 580, Risk Based Inspection, to pipelines for evaluating its methodology in regard to adequacy and simplicity.

Este trabalho apresenta os resultados da aplicação da metodologia de inspeção não intrusiva (INI) em equipamentos do sistema de dessulfurização de gás numa plataforma petrolífera, com o auxílio da inspeção baseada em risco utilizando a norma API RP 581. A inspeção não intrusiva é aplicada tendo como fundamentos as guias de inspeção, como a DNV-RP-G103, que reúne informações de como executar e justificar o seu uso, a fim de garantir a segurança das instalações, eliminando a necessidade de uma parada do equipamento para a realização da inspeção. Contudo nem todos os equipamentos puderam ser inspecionados por esta metodologia, devido a limitações operacionais e/ou construtivas. O trabalho conclui que a inspeção não intrusiva pode ser aplicada à inspeção de equipamentos sem prejuízo ao mapa de risco do equipamento ou da unidade, e naqueles onde não é possível à utilização somente da metodologia, a mesma poderá ser aplicada em conjunto com a inspeção convencional fornecendo informações importantes sobre o estado do equipamento, melhorando assim a confiabilidade do planejamento da parada de manutenção e uma redução dos custos envolvidos. / This paper presents the results of applying the methodology of non-intrusive inspection (INI) in electrical system flue gas desulphurization an oil rig, with the help of riskbased inspection using the API RP 581. The non-intrusive inspection is implemented with the guides as the foundations of inspection, such as DNV-RP-G103, which gathers information on how to make and justify its use, to ensure the safety of installations, eliminating the need for a parade equipment to perform the inspection. However not all equipment could be inspected by this method, due to operational limitations and / or constructive. The paper concludes that the non-intrusive inspection can be applied to inspection of equipment subject to the risk map of the equipment or unit, and those where it is not possible to use only the methodology, it may be applied along with conventional inspection providing important information on the status of the equipment, thereby improving the reliability of planning maintenance shutdown and lower costs.

[pt] Tradicionalmente, os equipamentos de elevação e transporte assumem uma posição de destaque na indústria, sendo as pontes rolantes os equipamentos mais utilizados. No caso da ThyssenKrupp Fundições Ltda., as pontes rolantes são responsáveis pelas principais paralisações dos negócios, trazendo prejuízos financeiros e operacionais. O emprego da IBR - Inspeção Baseada em Risco é bastante indicado para este tipo de equipamento, pois permite identificar as pontes rolantes que são críticas e deste modo estabelecer uma metodologia de inspeção eficiente, visando concentrar esforços nestes equipamentos de modo a reduzir seu risco de falha e garantir a manutenção dos negócios. Neste trabalho analisou-se um conjunto de pontes rolantes e componentes críticos da empresa ThyssenKrupp Fundições Ltda.. Para se cumprir este objetivo, foi aplicada a metodologia de IBR qualitativa para a análise do banco de dados de manutenção e inspeção. A teoria de IBR qualitativa usou uma matriz de risco COF x FOF (Conseqüência de Ocorrência de Falhas X Freqüência de Ocorrência de Falhas) onde cada uma das 20 pontes teve sua classe de risco estabelecida. Também foi feita a análise da freqüência de falhas dos componentes de todas as 20 pontes através dos registros de inspeção e manutenção localizados dentro do período de janeiro de 1995 a junho de 2002. Após a determinação das pontes rolantes críticas (risco alto e muito alto) e componentes críticos, foi elaborado um programa de inspeção para o gerenciamento dos mesmos, através de tabelas e fichas de inspeção onde a nova freqüência de inspeção foi calculada através da distribuição de probabilidade semi-empírica de Weibull. Além do programa de inspeção, foi proposta uma metodologia para análise dos resultados futuros obtidos com a aplicação do programa de inspeção e para proporcionar, através da realimentação do banco de dados, o contínuo aumento de sua eficiência. / [en] Traditionally, the transportation and elevation equipments assume a highlight position in the industry, being the overhead crane one of the mostly used equipments. As to the ThyssenKrupp Fundições Ltda, the overhead cranes are responsible for main causes for stopping of business, leading financial and operational lost. The use of RBI - Risk Based Inspection is very well indicated for this type of equipment since it allows the identification of which overhead cranes are critical and in this way the establish a mean of efficient inspection methodology, aiming to concentrate efforts on these equipments so as to reduce their failure risk and to guarantee the maintenance of the business. In this dissertation, a sub-set of overhead cranes and critical components of ThyssenKrupp Fundições Ltda was analyzed. In order to reach this objective, the RBI qualitative methodology was applied to the analysis of the maintenance and inspection database. The theory of the qualitative RBI used a risk matrix FOF x COF (Probability of Failure X Consequence of Failure) where each one of the 20 overhead crane had its class of risk established. Also, the components failure analysis frequency of all the 20 overhead cranes was made through the inspection registries situated in the period between January 1995 and June 2002. After determining the critical overhead crane (high and very high risk) and the critical components, an inspection program for their management was elaborated through means of table and inspection cards where the new inspection frequencies were determined through the Weibull distribution semi-empiric probability. Besides the inspection program, a methodology to analyze the future results obtained by the application of the inspection program was propose to offer suggestions for this continuous efficience raise.

Este trabalho apresenta os resultados da aplicação da metodologia de inspeção não intrusiva (INI) em equipamentos do sistema de dessulfurização de gás numa plataforma petrolífera, com o auxílio da inspeção baseada em risco utilizando a norma API RP 581. A inspeção não intrusiva é aplicada tendo como fundamentos as guias de inspeção, como a DNV-RP-G103, que reúne informações de como executar e justificar o seu uso, a fim de garantir a segurança das instalações, eliminando a necessidade de uma parada do equipamento para a realização da inspeção. Contudo nem todos os equipamentos puderam ser inspecionados por esta metodologia, devido a limitações operacionais e/ou construtivas. O trabalho conclui que a inspeção não intrusiva pode ser aplicada à inspeção de equipamentos sem prejuízo ao mapa de risco do equipamento ou da unidade, e naqueles onde não é possível à utilização somente da metodologia, a mesma poderá ser aplicada em conjunto com a inspeção convencional fornecendo informações importantes sobre o estado do equipamento, melhorando assim a confiabilidade do planejamento da parada de manutenção e uma redução dos custos envolvidos. / This paper presents the results of applying the methodology of non-intrusive inspection (INI) in electrical system flue gas desulphurization an oil rig, with the help of riskbased inspection using the API RP 581. The non-intrusive inspection is implemented with the guides as the foundations of inspection, such as DNV-RP-G103, which gathers information on how to make and justify its use, to ensure the safety of installations, eliminating the need for a parade equipment to perform the inspection. However not all equipment could be inspected by this method, due to operational limitations and / or constructive. The paper concludes that the non-intrusive inspection can be applied to inspection of equipment subject to the risk map of the equipment or unit, and those where it is not possible to use only the methodology, it may be applied along with conventional inspection providing important information on the status of the equipment, thereby improving the reliability of planning maintenance shutdown and lower costs.

Este trabalho apresenta os resultados da aplicação da metodologia de inspeção não intrusiva (INI) em equipamentos do sistema de dessulfurização de gás numa plataforma petrolífera, com o auxílio da inspeção baseada em risco utilizando a norma API RP 581. A inspeção não intrusiva é aplicada tendo como fundamentos as guias de inspeção, como a DNV-RP-G103, que reúne informações de como executar e justificar o seu uso, a fim de garantir a segurança das instalações, eliminando a necessidade de uma parada do equipamento para a realização da inspeção. Contudo nem todos os equipamentos puderam ser inspecionados por esta metodologia, devido a limitações operacionais e/ou construtivas. O trabalho conclui que a inspeção não intrusiva pode ser aplicada à inspeção de equipamentos sem prejuízo ao mapa de risco do equipamento ou da unidade, e naqueles onde não é possível à utilização somente da metodologia, a mesma poderá ser aplicada em conjunto com a inspeção convencional fornecendo informações importantes sobre o estado do equipamento, melhorando assim a confiabilidade do planejamento da parada de manutenção e uma redução dos custos envolvidos. / This paper presents the results of applying the methodology of non-intrusive inspection (INI) in electrical system flue gas desulphurization an oil rig, with the help of riskbased inspection using the API RP 581. The non-intrusive inspection is implemented with the guides as the foundations of inspection, such as DNV-RP-G103, which gathers information on how to make and justify its use, to ensure the safety of installations, eliminating the need for a parade equipment to perform the inspection. However not all equipment could be inspected by this method, due to operational limitations and / or constructive. The paper concludes that the non-intrusive inspection can be applied to inspection of equipment subject to the risk map of the equipment or unit, and those where it is not possible to use only the methodology, it may be applied along with conventional inspection providing important information on the status of the equipment, thereby improving the reliability of planning maintenance shutdown and lower costs.

The increased energy demand within South Africa has led to continued periods of load shedding. This has had an adverse impact on industry, quality of life and the economy as a whole. A larger requirement for production time, reduced downtime and an enlarged focus on health and safety have steered industry towards a paradigm shift in inspection and maintenance. These activities have progressed from a predominantly time-based (prescriptive) approach towards a risk-based approach. Generally accepted standards like BS EN 16991:2018 and API RP 580 give a comprehensive outline of the basic elements for developing, implementing and maintaining a risk-based inspection program. API RP 581 takes this outline one step further and contains the quantitative methods that support the minimum guidelines presented by API RP 580. Similarly, Kent W. Mühlbauer’s approach has developed a relative risk ranking model for petroleum and gas pipelines, which outlines a qualitative method for representing risk. None of these models are however directly applicable to predicting the failure of pressurised boiler equipment due to the mechanism of corrosion fatigue. API RP 580 / 581 was primarily developed for the oil and gas industry and have practical limitations when applied to pressurised equipment typically found in utilities. BS EN 16991:2018 supplies a framework for utilities, but doesn’t go into the specific detail of how to structure, formulate and apply a risk based management model. The methodology laid out by Kent W. Mühlbauer, while practical and easily implemented, was designed for oil and gas pipelines. A systematic methodology to evaluate the risk associated with specific failure mechanisms in boilers, such as corrosion fatigue, does not exist or is not readily available. A comprehensive risk-based predictive model, using aspects of the abovementioned standards and guides, was developed to demonstrate the predictability of corrosion fatigue in sub-critical boilers. Weightings were assigned to contributory causes to corrosion fatigue, which then allocated relative risk ranks to certain segments within a boiler. Operators and owners of boilers can derive benefit from this model by focusing inspection, maintenance and alteration activities on those equipment locations with the highest relative risk score. / Dissertation (MEng (Metallurgical Engineering))--University of Pretoria 2020. / Eskom Power Plant Engineering Institute (EPPEI) Supervisor: Mr. L. Reddy / Materials Science and Metallurgical Engineering / MEng (Metallurgical Engineering) / Unrestricted

Gas plants consist of several pieces of both critical static and rotating equipment, which operate continuously under severe operating conditions. These pieces of equipment are permanently subjected to be inspected and maintained during total shutdown of plant facilities to execute Turnaround Maintenance (TAM) event. The TAM is the largest maintenance activities used in most oil and gas companies in terms of both cost and time. Oil and gas companies have suffered losses in the production and enormity in the TAM cost due to duration and interval of TAM which have randomly estimated without taking the size and age of plants into account. Sirte Oil Company (SOC) was a good example and used as a reference point for other gas plants to achieve the aim of this thesis associated with optimising TAM scheduling for gas plants (decreasing duration and increasing interval of TAM) by implementing the TAM model. The contribution of this research is in developing the TAM model, consisting of four stages, which is broken down into four main stages: First stage; removing Non-critical pieces of Equipment (NEs) from the Scope of Work (SoW) of TAM to proactive maintenance strategies. Second stage; selecting Critical Static pieces of Equipment (CSEs) that constitute the highest risk based on Risk-Based Inspection (RBI). Third stage; selecting Critical Rotating pieces of Equipment (CREs) that constitute the highest risk based on Risk-Based Failure (RBF). Fourth stage; defining the optimum duration and interval of TAM based on Failure Distributions (FDs). Consequently, the TAM model developed in this study provides a novelty in the TAM event and decision making process. This is basically about optimisation of TAM scheduling in the medium and long-term, characterized by decreasing duration and increasing interval of TAM based on both CSEs and CREs to achieve the TAM model results. The result is the reduction in TAM cost and production losses, and the improvement in reliability and availability requirements of gas plants according to the residual life of critical equipment and operating conditions. To ensure reliability and consistency of the TAM model, it was validated with three Libya-plants SOC and data from three published case studies. The results from the validation of the TAM model are consistent with the real duration and interval of TAM in most plants SOC. The research concludes that the developed TAM model is a reliable and applicable tool to assist decision-makers in the estimation of TAM scheduling for any a processing plant.

<p dir="ltr">In recent years (circa 2024), the purpose of pedestrian bridges has extended beyond simply providing a safe route for pedestrians to cross an obstacle. Nowadays, pedestrian bridges are becoming works of art integrated into the design plan for the whole city. The pleasant appearance of these bridges, however, comes at the cost of requiring complex structural analysis and design, unique fabrication requirements, and construction challenges. Therefore, inspecting different types of pedestrian bridges efficiently and adequately is crucial to avoid unexpected failure during their service life. While National Bridge Inspection Standers (NBIS) regulations are only applicable to all publicly owned <i>highway</i> bridges with spans longer than twenty feet, there is no standard inspection criteria applicable across the board for any type of pedestrian bridge (FHWA 2022a). The current criteria, implemented ad-hoc by many owners, is to inspect pedestrian bridges using the traditional calendar-based inspection approach. This method is based on assigning an inspection interval not to exceed some time frame (typically 24-months) for all bridges with exceptions for some specific bridges receiving special inspections. Although this method may provide an adequate level of safety for some bridges, it doesn’t explicitly account for the current condition, variation in operational environment, and the design characteristics of the bridge. In addition, the current inspection practice of pedestrian bridges considers only inspecting bridge's <i>structural conditions</i> while some unique safety and serviceability criteria should be considered to attain an optimum level of safety and serviceability for pedestrians and cyclists on the bridge such as railing, lighting, walking surface, etc.</p><p dir="ltr">The main objective of this research is to develop an inspection criterion specifically applicable to pedestrian bridges to ensure the optimal allocation of inspection resources while maintaining an optimum safety and serviceability. In its final form, the Risk Based Inspection (RBI) methodology is applied in conjunction with reliability concepts and expert inputs from the Risk Assessment Panel (RAP) of the Indiana Department of Transportation (INDOT) to systematically evaluate the key components of the proposed approach. The proposed methodology is based on the Reliability Based Inspection procedures presented in NCHRP 782 report (Washer et al. 2014a). In this method, the inspection interval is determined based on the risk assessment, which is the product of a combination of occurrence and consequence factors. The occurrence factor is calculated based on design, loading (mechanical and environmental), and condition attributes for each type of damage. The consequence factor measures the outcomes of the occurrence of the damage under consideration. This factor is evaluated at two stages, an immediate consequence in which outcomes impact the safety of the service on and under the bridge, and a short-term consequence, in which effects influence the serviceability of the service under the bridge. Furthermore, a new factor is also introduced to the RBI approach. Specifically, what will be referred to as the inspection effectiveness factor which attempts to accounts for the reliability of the inspection technique to identify and quantify a specific defect for a given components of the bridge. The proposed approach is then applied and validated on a set of real in-service pedestrian bridges with varying materials and structural systems. The results demonstrate that the approach improves the safety and serviceability of pedestrian bridge inspections. Furthermore, it ensures a better allocation of the limited inspection resources and proves to be more cost-effective compared to current inspection practices.</p>

Risk based approaches are gaining currency as industry looks for rational, efficient and flexible approaches to managing their structures and equipment. When applied to inspection and maintenance of industrial assets, risk based approaches differ from other approaches mainly in their assessment of failure in its wider context and ramifications. These advanced techniques provide more insight into the causes and avoidance of structural failure and competing risks, as well as the resources needed to manage them. Measuring risk is a challenge that is being met with state of the art technology, skills, knowledge and experience. The thesis presents risk based approaches to solving two specific types of problem in the management of offshore structures and equipments. The first type is finding the optimum timing of an asset life management action such that financial benefit is maximised, considering the cost of the action and the risk (quantified in monetary terms) of not undertaking that action. The approach presented here is applied to managing remedial action in offshore wind farms and specifically to corroded wind turbine tower structures. The second type of problem is how to optimise resources using risk based criteria for managing competing demands. The approach presented here is applied to stocking spares in the shipping sector, where the cost of holding spares is balanced against the risk of failing to meet demands for spares. Risk is the leitmotiv running through this thesis. The approaches discussed here will find application in a variety of situations where competing risks are being managed within constraints.

[pt] A Manutenção e Inspeção Baseada em Risco (IBR) compreende a utilização de ferramentas de cálculo de engenharia como análise estrutural por elementos finitos, análise de corrosão e fadiga, análise de risco e confiabilidade estrutural, de forma integrada, a fim de elaborar os planos de inspeção de maneira racional otimizada. No caso de inspeção de balsas para serviço offshore, particularmente da estrutura do convés principal da balsa, técnicas de análise de risco podem ser aplicadas para que se possam determinar os intervalos de inspeção de cada elemento da estrutura. Como resultado final, tem-se um plano de inspeção otimizado e aplicado à realidade estrutural da unidade. A presente dissertação tem por objetivo propor um método de predição baseado em IBR para aperfeiçoamento de processos de tomada de decisão referentes à manutenção de balsas para serviço offshore de uma grande empresa brasileira do setor de petróleo e gás natural. Apresenta-se um estudo de caso focalizando uma aplicação do método de predição em uma das balsas de serviço offshore da empresa – a Balsa de Serviço 3 (BS-3). Os resultados do estudo de caso permitem afirmar que a adoção de ferramentas de inspeção baseada em risco podem aumentar o TLV (Tempo Limite de Vida) das balsas de serviço offshore. Como consequência, os benefícios potenciais são: redução das incertezas associadas; identificação de avarias devido à deterioração estrutural; redução de custos de manutenção; e, principalmente, diminuição do tempo da paralisação das balsas de serviço. / [en] Risk-Based Inspection (RBI) involves the use of engineering calculation tools such as finite element structural analysis, corrosion and fatigue analysis, risk analysis and structural reliability in an integrated framework, in order to develop inspection plans in a rational and optimized manner. RBI attempts to map the structure degradation curve, in deterministic or probabilistic way. Once defined the degradation curve for the different areas of the structure, risk analysis techniques are applied to determine inspection intervals concerning each element of the structure. As final result, it is possible to obtain an optimized inspection plan applied to the structural reality of the unit. The objective of this dissertation is to propose a prediction method, based on RBI, to improve the decision-making process focusing on maintenance of offshore service barges of a large oil and gas company in Brazil. It presents a case study concerning an application of this prediction method in one of the offshore service barges of this company – Offshore Service Barge 3 (BS-3). The results show that the adoption of preventive inspections can enlarge the TLV (Time Limit of Life) of this type of unit. As a consequence, the potential benefits are: reduction of uncertainties; identification of faults due to structural deterioration; maintenance costs reduction; and, decreasing of time breakdowns concerning barge services.