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In the thesis failure analysis and assessment of water supply system in considered city was presented. The analysis was prepared on the basis of the exploitation data obtained from water company. The characteristic of water distribution system was presented. Indicators of failure rates were calculated. Data were presented in division to diameter, material, type, season and month of failure. [ABSTRACT FROM AUTHOR]

The subject of this paper is a failure analysis of water supply failure frequency in one of the cities in Poland. Operating data on the failure rate of water supply pipelines in the city were used. The analysis of water pipes' failures, including pipes diameters, their age, the material they are made from and their function in the water supply subsystem in the city was made. There is a noticeable downward trend in both the number of failures as well as the failure rates of water pipes. The value of failure rate indexes corresponds to national and international trends. The average failure rate for the main pipelines is λ Mavg = 0.98 km − 1 a − 1 , the distribution pipelines λ Ravg = 0.42 km − 1 a − 1 and the water connections — λ Pavg = 0.35 km − 1 a − 1 . The majority of failures (45.62%) happen in the distribution pipelines, representing about 53% of the total length of the pipelines. Detailed analysis of the water network failure should be a main element of the managing system of the urban water networks, particularly in strategic modernization plans. [ABSTRACT FROM AUTHOR]

The important and crucial issue concerning water supply functioning in terms of conducting failure analysis were discussed. In the work failure indicators, water losses and availability of water services, that define standards of quality water services and their values were determined based on data from exploitation. In order to understand the current situation of water supply infrastructure it is necessary to perform periodic analyzes of water supply network failure, which was proposed in this paper. A detailed analysis of the failure and the water loss of the water supply network should be the main element of the urban management water supply network, particularly in the strategic plans for its modernization. [ABSTRACT FROM AUTHOR]

The aim of this paper is to present the novel approach to risk assessment in combination with failure and consequence analysis, depending on two parameters defined by the fuzzy functions: the repair time of water pipe and the cost of water pipe repair, what allow to determine particular risk levels. The presented methodology can be used to describe the functioning of the public water supply in terms of its renewal. [ABSTRACT FROM AUTHOR]

Initiated by a case study to assess the effectiveness of the modernisation actions undertaken in a water supply system, some R&D activities were conducted to construct a global predictive model, based on the available operational failure and recovery data. The available operational data, regarding the water supply system, are the pipes' diameter, failure modes, materials, functional conditions, seasonality, and the number of failures and time-to-recover intervals. The operational data are provided by the water company responsible of the supply system. A predictive global model is proposed based on the output of the operational data statistical assessment. It should assess the expected effectiveness of decisions taken in support of the modernisation and the extension plan. [ABSTRACT FROM AUTHOR]

Within the frame of upgrading and modernisation of the Water Supply System (WSS), our work is focussing on the safety systems/devices implemented or that should be implemented in the WSS. The implementation of safety systems is supposed to reduce hazard occurrence and hazardous consequences in case of a WSS unsafe disruption. To assess this reduction, we preconise the use of the safety integrity levels standards. The implementation of the safety systems/devices is undertaken on the ground of the multi-barriers safeguard approach. The "Water Contamination Hazard" is considered in the paper. A case study is presented, assessed and conclusions are drawn. The methodology presented in the paper and the results of the case study assessment will contribute to the decision-making regarding the upgrading of the safety and the performance of the WSS. [ABSTRACT FROM AUTHOR]

Analysis and assessment of the reliability and safety of a gas-supply system is a key issue, given its status as critical infrastructure. A gas-supply system is characterised by continuous operation and a consequent need to achieve a high level of operating reliability and safety. Such a system has its unique aspects, with particular elements having their different functions while also simultaneously interacting in the context of the integral whole. In such circumstances, risk analysis can prove useful in planning activity to prevent damage, and also in the devising of rescue scenarios. Thus, the purpose of the analysis presented here has been to supply the information that is necessary in decision-making relating to risk reduction. One of the most comprehensive assessment methods is based on the expected value of gas shortage. Basic formulae with which to determine a generalised indicator of system reliability are also presented, with risk viewed as synonymous with the unreliability of gas supply. This paper then proposes a method by which an indicator of the expected efficiency of operation may also be determined as the quotient of chance and absolute risk. The thinking in this article has been developed on the basis of data from a real gas-supply system, while the computational methods deployed allowed applications to draw conclusions regarding possible modification of the expected gas shortages method. [ABSTRACT FROM AUTHOR]

The development of appropriate methods by which to assess the functioning of gas pipelines helps limits the consequences of disasters, in that way protecting users better. Assessment methods of this kind are presented in this paper, which advocates the integrated risk area identification method. The risk taken account of is understood to be a function of the probability or frequency of occurrence of undesirable events, and comes with parameters defining the consequences of these events, should they arise, in terms of their magnitude. The level of system vulnerability to events of these types is a factor considered, and the risk calculation is of a kind that encompasses both quantitative and qualitative aspects. The approach taken is regarded as a quick and simple risk-assessment tool applicable to the daily operation of gas networks for a gas company. Specifically, the framework of the research carried out extends to: (1) Estimation of the average cost of failure of gas pipelines in the case of an urban agglomeration in SE Poland; (2) assessment of the level of integrated risk facing the gas-supply subsystem, by reference to the risk area identification method; (3) failure forecasting by way of regressions with delay; and (4) conclusions regarding failure risk assessment in a gas-supply network, as well as a consideration of prospects. The framework referred here, thus constitutes the basis for both analysis and assessment of the safety of a gas-supply system. [ABSTRACT FROM AUTHOR]