• Title/Summary/Keyword: water distribution pipe system

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Reliability Analysis for Probability of Pipe Breakage in Water Distribution System (상수관망의 파이프 파괴확률 산정을 위한 신뢰성 해석)

  • Kwon, Hyuk Jae;Lee, Cheol Eung
    • Journal of Korean Society of Water and Wastewater
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    • v.22 no.6
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    • pp.609-617
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    • 2008
  • Water pipes are supposed to deliver the predetermined demand safely to a certain point in water distribution system. However, pipe burst or crack can be happened due to so many reasons such as the water hammer, natural pipe ageing, external impact force, soil condition, and various environments of pipe installation. In the present study, the reliability model which can calculate the probability of pipe breakage was developed regarding unsteady effect such as water hammer. For the reliability model, reliability function was formulated by Barlow formula. AFDA method was applied to calculate the probability of pipe breakage. It was found that the statistical distribution for internal pressure among the random variables of reliability function has a good agreement with the Gumbel distribution after unsteady analysis was performed. Using the present model, the probability of pipe breakage was quantitatively calculated according to random variables such as the pipe diameter, thickness, allowable stress, and internal pressure. Furthermore, it was found that unsteady effect significantly increases the probability of pipe breakage. If this reliability model is used for the design of water distribution system, safe and economical design can be accomplished. And it also can be effectively used for the management and maintenance of water distribution system.

determination of Optimum Pipe diameter Using Multi-Stage Iterative Method in Water Distribution system (다단계 반복기법을 이용한 관로시스템의 최적관경 결정)

  • Han, Geon-Yeon;Park, Jae-Hong
    • Journal of Korea Water Resources Association
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    • v.31 no.3
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    • pp.327-335
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    • 1998
  • The distribution network is an essential part of all water supply systems. The cost of this portion of any sizable water supply system may amount to most of the entire cost of the project. This study tried to reduce the cost of the distribution system through optimization in system design. To determine pipe diameter considered in water distribution system design, a iterative procedure linked the flow analysis model and optimization model was used. Linear theory was introduced to analyze flowrate and revised-simplex method based on linear programming is used to optimize pipe diameter. This model was applied to wter distribution system with 22 and 35 pipes, and rapidly determine optimized commercial pipe diameters. Keywords : water distribution system, revised simplex method, optimum pipe diameters.

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A Methodology to Quantifying Benefit for Implementing Smart-Pipe to Lifeline Systems (라이프라인의 Smart-Pipe 시스템 도입을 위한 이익정량화 방안)

  • Jun, Hwan-Don;Kim, Joong-Hoon;Cho, Moon-Soo;Baek, Chun-Woo;Yoo, Do-Guen
    • Journal of the Korean Society of Hazard Mitigation
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    • v.8 no.4
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    • pp.61-66
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    • 2008
  • As the water distribution system which is one of the critical lifeline system is deteriorated and pipe failures occur frequently, the more efficient pipe monitoring system becomes a critical issue in the water industry. One of the pipe monitoring systems is called "Smart-pipe System" which is permanent, comprehensive and an automated SIM (Structural Integrity Monitoring) system and has superiorities to existing monitoring system. To implement a smart-pipe system on a water distribution system, assessment of its indirect benefit obtaining from smartpipe such as the ratio of preventing water main failures must be preceded. However, only some researches on this field have been performed. In this paper, the concept of smart-pipe system is compared with the current monitoring systems for a water distribution system, and a method to quantify its benefit using the inconvenient time for customers is suggested. The suggested method was applied to a real water distribution system to estimate its applicability and benefit.

The Regulations and Guidelines for Management of Corrosive Water and Pipe Corrosion in Drinking Water Distribution System in North America (상수원 관망 부식 제어를 위한 부식성 수질 관리: 북미지역 관리 사례 및 국외 현황)

  • Kim, Minhee;Hyun, Seunghun;Lee, Won-Seok;Loretta, Y. Li
    • Journal of Korean Society on Water Environment
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    • v.33 no.3
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    • pp.359-369
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    • 2017
  • Water distribution systems supply drinking water to consumers' taps. Internal corrosion of metallic pipe used in drinking water distribution systems has reduced water quality and led to increased levels of toxic heavy metals such as lead, copper and nickel. These problems have been experienced to varying degrees by water utilities in many countries. North America has successfully managed and controlled pipe corrosion and corrosive water in water distribution system based on various policies, regulations and rules. Practical and engineering guidelines for evaluation of pipe corrosion and determination of treatment options are also provided to assist drinking water supplies. In addition, the corrosion mechanism in water distribution systems, such as the complex effects of physical and chemical parameters on the corrosion pipes has been improved to accurately predict corrosion rates of metallic pipes in actual water distribution systems. This paper reviews various regulations, policy statement, and treatment produces on controlling corrosion in drinking water distribution systems in US and Canada and then offers suggestion for management of corrosive water and pipe corrosion in drinking water distribution system in Korea.

Development and Applications of a Methodology and Computer Algorithms for Long-term Management of Water Distribution Pipe Systems (상수도 배수관로 시스템의 장기적 유지관리를 위한 방법론과 컴퓨터 알고리즘의 개발 및 적용)

  • Park, Suwan
    • Journal of Korean Society on Water Environment
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    • v.23 no.3
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    • pp.356-366
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    • 2007
  • In this paper a methodology is developed to prioritize replacement of water distribution pipes according to the economical efficiency of replacement and assess the long-term effects of water main replacement policies on water distribution systems. The methodology is implemented with MATLAB to develop a computer algorithm which is used to apply the methodology to a case study water distribution system. A pipe break prediction model is used to estimate future costs of pipe repair and replacement, and the economically optimal replacement time of a pipe is estimated by obtaining the time at which the present worth of the total costs of repair and replacement is minimum. The equation for estimating the present worth of the total cost is modified to reflect the fact that a pipe can be replaced in between of failure events. The results of the analyses show that about 9.5% of the pipes in the case study system is required to be replaced within the planning horizon. Analyses of the yearly pipe replacement requirements for the case study system are provided along with the compositions of the replacement. The effects of water main replacement policies, for which yearly replacement length scenario and yearly replacement budget scenario are used, during a planning horizon are simulated in terms of the predicted number of pipe failures and the saved repair costs.

Analysis of Pipe-Burst effect in Water Distribution Network (상수관망의 관로파열 영향 해석)

  • Park, Jae-Hong
    • Journal of Korea Water Resources Association
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    • v.35 no.6
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    • pp.665-675
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    • 2002
  • It is very closely related with the reliability of the pipe network to predict pipe burst and diminish burst effect in water distribution system. Most of the engineers have not consider pipe layout and the effect of pipe burst in conservative pipe network design. In this study, The effect of pipe burst in the network is analyzed with respect to pipe network geometric topology and the method of increasing the system reliability is presented by reducing pipe-burst effect. In existing pipe system, it is only designed to the closed loop system but in case of each pipe burst, it cannot transmit appropriate water to consumers and occurs severe hydraulic head drop in many nodes. The techniques developed in this study allow proper pipe diameter and pipe layout to pipe system through the analysis of pipe-burst effect. Thus, when each pipe is bursted, pipe system is prevented from severe pressure head drop in demand nodes and can supply stable flowrate to consumer.

A Methodology for Evaluating the Superiority between Different Valve Distributions Based on Pipe and Valve Failure Simulation (상수관로와 밸브 파괴모의를 기반으로 한 다른 제수밸브 분포간의 우열성 평가방법)

  • Jun, Hwan-Don;Park, Su-Wan
    • Journal of Korea Water Resources Association
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    • v.40 no.6 s.179
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    • pp.495-502
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    • 2007
  • For a water distribution system, it is necessary to evaluate the superiority between different valve distributions in order to improve the reliability of the water distribution system. In cases of placing more valves to an exiting system or building a new system, we suggest a methodology to select a proper valve distribution after various valve distributions are compared. The suggested methodology is based on simulations of pipe and valve failures to estimate failure impacts of the water distribution system due to pipe and valve failures. It is quantified by the number of customers out of service per pipe failure resulted from pipe and valve failures. To demonstrate its applicability, the methodology is applied to a real water distribution system with two different valve distributions and determines the superiority between those valve distributions. Also, customers out of service along with various valve reliabilities are estimated for those valve distributions to prove the effect of the valve reliability on the reliability of a water distribution system.

An Algorithm for Searching On-Off Valves to Isolate a Subsystem in a Water Distribution System (상수관망의 부분적 격리를 위한 제수밸브 탐색 알고리듬)

  • Jun, Hwan Don;Kim, Joong Hoon
    • Journal of Korean Society of Water and Wastewater
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    • v.20 no.1
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    • pp.35-43
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    • 2006
  • Concerns related to protecting, identifying, and isolating of subsystems of a water distribution network have led to the realization of the increased importance of valves in the system. The most important purpose of valves in water distribution systems is to isolate a subsystem due to breakage, maintenance activities, or contamination. A subsystem called segment is isolated by the closure of adjacent valves. Minimizing the pipe failure impact, an efficient algorithm is required to identify adjacent valves quickly. In this paper, an algorithm to identify adjacent valves to be closed to isolate a subsystem from the remainder of a network when a pipe failure is presented. The algorithm is operated on a matrix called the valve location matrix containing the information of valve locations. An application to an existing water distribution system demonstrates the developed algorithm efficiently locates the adjacent valves for the isolation of a broken pipe.

Applicability of Several Skeletonization Methods for the Transient Analysis in the Water Distribution System (상수관망 부정류 해석을 위한 관망 간략화 방법에 대한 연구)

  • Lee, Jong-Pil;Kim, Hyung-Guen;Kim, Sang-Hyun;Lee, Hyun-Dong
    • Proceedings of the Korea Water Resources Association Conference
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    • 2004.05b
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    • pp.521-526
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    • 2004
  • It is necessary to analyze the unsteady flow in the pipe network for the better operation and controls, but there are some problems in actual pipe network simulation, such as collecting a large amount of information in the field, operating highly upgraded computer system, and keeping a big storage device to run analysis program. The skeletonization method is used to cope with the problems in this paper. It is expected to reduce computation time, researcher's efforts, and costs for the analyzing the pipe network. The impact of individual pipe elements to the behavior of the water distribution system can be accounted in the process of skeletonization. However it is also important to study continuously about how to apply the skeletonization method for each of different cases, because inadequate uses may bring simulation to a false result. This paper introduces basic theories and skeletonizing examples in the actual pipe network in Dae-gu city.

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Development of the Computational Model to Evaluate Integrated Reliability in Water Distribution Network (상수관망의 통합신뢰도 산정을 위한 해석모형의 개발)

  • Park, Jae-Hong;Han, Kun-Yeon
    • Journal of Korea Water Resources Association
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    • v.36 no.1
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    • pp.105-115
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    • 2003
  • The computation model which evaluates combined hydraulic and mechanical reliability, is developed to analyze the integrated reliability in water distribution system. The hydraulic reliability is calculated by considering uncertain variables like water demand, hydraulic pressure, pipe roughness as random variables according to proper distribution type. The mechanical reliability is evaluated by analyzing the effect of pipe network with sequential failure of network components. The result of this study model applied to the real pipe network shows that this model can be used to simulate the uncertain factors effectively in real pipe network. Therefore, The pipe-line engineers can design and manage the network system with more quantitative reliability, through applying this model to reliable pipe network design and diagnosis of existing systems.