Sterilizer Reliability Analysis Using Reliability Block Diagram Based on Failure Identification Through Fault Tree Analysis

A sterilizer is a pressurized steam vessel used to boil palm oil. The condition of the sterilizer at PT .X often emits steam at the door and body of the stew. Throughout 2020, there were 12 critical components that were frequently damaged, such as ball valve, actuator, exhaust valve, packing door, elbow, condensate nozzle, liner, pipe, condensate valve, strainer valve, pipe flange, and packing flange. Fault Tree Analysis is an analysis tool that graphically translates the combinations of errors that cause system failures. Reliability Block Diagram is a diagramming method for showing how reliability components contribute to the success or failure of a complex system. Based on the results of the failure calculation using fault tree analysis, the probability of failure of the horizontal sterilizer component is the ball valve 12.2%, exhaust valve 10.9% actuator 6%, door packing 0.24%, elbow 0.24%, condensate nozzle 4.8%, liner 8.61%, 0.25% pipe, 0.21% condensate valve, 4.4% filter valve, 0.22% pipe flange and 0.27% packing flange. The reliability value of the horizontal sterilizer from the calculation using the reliability block diagram is 85.69% if it operates for 8 hours, 62.93% if it operates for 27 hours, 39.6% if it operates for 54 hours, 13.34% if it operates for 117 hours. o'clock. o'clock. o'clock. hours and 1.81% when operating for 234 hours. To maintain reliability above 60%, the preventive maintenance schedule is: Every 80 hours of operation a door packing inspection is carried out. Every 234 hours of operation, elbow tubing and flanges are checked. Every 300 hours of operation, a pipe inspection is carried out. Every 450 operational hours an inspection is carried out on the ball valve, condensate nozzle, liner, actuator, and exhaust valve. Every 30 hours of operation, valve condensate, filter valves and packing flanges are checked.

Estimation of the failure flow of a set of passenger car doors

An estimation of the failure flows is a prerequisite for the operation of industrial products. It is based on statistical data about failures that occur within technical items in the process of their operation. In the technical product documentation, this indicator shall be featured in the “Dependability parameter estimation” section. The dependability analysis of rolling stock is still affected by the difficulty of defining the methodology for evaluating this parameter at various system levels. For the purpose of analysing a multicomponent system, a reliability block diagram should be developed, and the possible replacement (redundant) elements should be taken into consideration. Multicomponent systems are often represented through various block diagrams, where, among others, the “m-out-of-n” structure may be used referring to a system with a parallel arrangement of elements that is operable when at least m elements operate. An example of such system is a set of passenger car doors. The manufacturers and customers may have different approaches to calculating technical system dependability. First, the required dependability indicator for the entire train is defined that, in turn, defines the dependability requirements for a car. At the same time, the dependability indicator for a car is determined by the respective values of its components (subsystems, units and parts). However, the nature of the relationship between a car and its components is not always taken into account. At the same time, car manufacturers can and should define in the regulatory documentation (and later supervise in operation) the dependability indicators for a set of doors (components of a car in our case) as a single system. However, the failure criteria of a set of doors are not always defined. This paper examines the method of calculating the failure flow for a set of passenger car doors based on operational data and the failure flow of a single door. Aim. To propose a method for calculating the failure flow of a set of 6 car doors by analysing the possible reliability block diagrams with subsequent transition to transition and state graphs.Conclusions. A number of block diagrams were developed for the purpose of dependability calculation of sets of passenger car doors based on the system failure criterion. The failure flow of a set of car doors was calculated according to the developed block diagrams. It is concluded that the Markovian method of calculating the failure flow is of higher priority than the logic-and-probability approach, since it takes into account the recovery factor. A Markovian method was proposed for calculating the failure flow and recovery time of a set of car doors for the “3-out-of-4” reliability block diagram.

Mission-based reliability prediction in component-based systems

This paper develops a framework for the extraction of a reliability block diagram in component-based systems for reliability prediction with respect to specific missions. A mission is defined as a composition of several high-level functions occurring at different stages and for a specific time during the mission. The high-level functions are decomposed into lower-level functions, which are then mapped to their corresponding components or component assemblies. The reliability block diagram is obtained using functional decomposition and function-component association. Using the reliability block diagram and the reliability information on the components such as failure rates, the reliability of the system carrying out a mission can be estimated. The reliability block diagram is evaluated by converting it into a logic (Boolean) expression. A modeling language created using the Generic Modeling Environment (GME) platform is used, which enables modeling of a system and captures the functional decomposition and function-component association in the system. This framework also allows for real-time monitoring of the system performance where the reliability of the mission can be computed over time as the mission progresses. The uncertainties in the failure rates and operational time of each high-level function are also considered which are quantified through probability distributions using the Bayesian framework. The dependence between failures of components are also considered and are quantified through a Bayesian network (BN). Other quantities of interest such as mission feasibility and function availability can also be assessed using this framework. Mission feasibility analysis determines if the mission can be accomplished given the current state of components in the system, and function availability provides information whether the function will be available in the future given the current state of the system. The proposed methodology is demonstrated using a radio-controlled (RC) car to carry out a simple surveillance mission.

Assessment of availability of street light system: A study of Warri, Delta State, Nigeria

The study computes the availability of street lighting system in Warri. This system under study consists of subsystems that are known as workstations. A generator and sets of street light make up a workstation. The power source and the street lighting were modeled into series and parallel combinations. Reliability Block Diagrams and Path Tracing Method were employed assuming independent failure of the components. The availability of the set of street lightings, workstations and hence the availability of the system were determined. Results of the study show that users in Cemetery road had the least availability of 62.19% for the period. The implication is that users travelling along this road experienced wide variation of light that could lead to accidents. Keywords: Availability, Street Lighting and Reliability block diagram

Засоби автоматизованого формулювання умов працездатності складних технічних систем

Під надійністю техніки розуміють здатність системи або її складових виконувати свої функції за заданих умов та у визначений період часу. Надійність є комплексною характеристикою технічної системи і, відповідно до її призначення, може включати: безвідмовність, довговічність, ремонтопридатність й інші атрибути або їх комбінації. Надійнісний аналіз проводиться з використанням певної кількості засобів графічного моделювання для забезпечення наочності етапів процесу, таких як структурні схеми надійності, дерева відмов та ін. Структурні схеми надійності (англ. Reliability Block Diagram) є простим, але наочним методом демонстрації зв'язків між елементами системи за допомогою блоків і з'єднувальних ліній. Моделювання структури технічної системи і визначення характеристик її складових з використанням структурної схеми надійності є потужним та наочним засобом, але складність його зростає відповідно до кількості елементів та вузлів системи. Методи аналізу структурних схем мають експоненціальну складність, яка залежить від кількості елементів та способу їх розміщення. Для вирішення цієї проблеми розроблено засоби автоматизованого формулювання умов працездатності складних технічних систем, які складаються з: алгоритму обходу структурної схеми надійності, алгоритму виявлення послідовного з'єднання та алгоритму виявлення паралельного з'єднання, які виявляють сегменти, котрі з'єднані між собою послідовно та паралельно відповідно. Також подано програмне забезпечення візуалізації структурних схем надійності та автоматизованого формулювання умов працездатності технічних систем, яке дає змогу звільнити користувача від багаторазового виконання рутинних операцій та автоматизувати процес формування вхідних даних для подальшого надійнісного аналізу.

Analisis Sistem Reliability dengan Pendekatan Reliability Block Diagram

Rendahnya reliability suatu sistem dapat mengakibatkan timbulnya downtime. Sedangkan rendahnya availability dapat mengakibatkan turunnya performance dari suatu sistem karena banyaknya waste time. Sistem extrussion pada PT. X berbentuk countinous process, apabila salah satu komponen pada mesin mengalami kerusakan akan menyebabkan terhentinya proses. Terdapat lima belas mesin yang tersusun secara seri pada proses extrussion, yakni uncoiler, welding, looping,extruder 90. Extruder 70, microwave 1,microwave 2, oven 1, oven 2,oven 3, cooling batch, breaking, bending, pulling, dan cutting. Sistem extrussion digambarkan dalam diagram Reliability Block Diagram. Tujuan dilakukannya penelitian ini adalah memodelkan sistem dengan menggunakan metode Reliability Block Diagram, mengetahui reliability dari keseluruhan system, dan mengetahui critically equipment. Data yang diolah merupakan data kerusakan mesin dari tahun 2006-2017, kemudian data tersebut diolah untuk menentukan reliability dari masing-masing komponen. Software yang digunakan adalah Software Reliasoft Blocksim 11. Hasil dari penelitian ini adalah nilai reliability sistem 0,431407 dengan t 100 jam.