• 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.

• Steel and Composite Structures
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• v.35 no.2
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• pp.171-186
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• 2020

This paper aims at providing insights on the use of thermosetting liner for the repair of offshore pipelines exposed to corrosion and leakage. The work which covers both experimental and numerical approaches were aspired due to the high cost of repair for pipelines, limitations of thermoplastic material and limited study of reinforced thermosetting liner. The experiment involves a destruction test called the burst test, carried out on an API 5L X42 carbon steel pipe under four case studies, namely (i) intact pipe, (ii) pipe with corrosion defect, (iii) pipe with corrosion defect and repaired with thermosetting liner and (iv) pipe with leakage and repaired with thermosetting liner. The numerical simulation was developed to first validate the experimental results and later to optimize the design of the thermosetting liner in terms of the number of layers required to restore the original strength of the pipe. The burst test shows an improvement in 23% of the burst capacity for the pipe with corrosion defects, after being repaired with a three-layer thermosetting liner. The parametric studies conducted showed that with an addition of thermosetting layers, the burst capacity improves by an average of 1.85 MPa. In conclusions, the improvement in strength can be further increased with increasing thickness of the thermosetting liner. The thermosetting liner was also determined to fail first inside the host pipe.

• Journal of Korean Society of Water and Wastewater
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• v.25 no.2
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• pp.141-152
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• 2011

In this study, we extracted effective factors of pipe burst from the status data of water asset, operating data of pressure, volume and etc. and 7 years' pipe burst and repair records. The extracted factors were sorted by each attribution and then a statistical analysis was performed to generate a pipe burst probability function using the logistic regression model. As the result, material, diameter, length, laying year, pressure and road width affected to pipe burst significantly. Especially, in case of small diameter, laying year was most effective factor and in case of steel pipe, external loading was main cause of burst, and in case of cast iron, PE, PC, HP pipes, the deterioration of joint was main cause. The other side, as a result of Hosmer-Lemeshow goodness of fit test the models are turned out significant statistically. Also the classification criteria were determined to minimize the total cost from classification errors, when the predicted probability was more than 18% this pipe could have a chance of burst.

• Journal of Korean Society for Quality Management
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• v.48 no.4
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• pp.597-608
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• 2020

Purpose: The purpose of this paper is to present a probability distribution of the burst pressure of API 5L X65 pipes for the reliability assessment of corroded gas pipelines. Methods: Corrosion is a major cause of weakening the residual strength of the pipe. The mean residual strength on the corrosion defect can be obtained using the burst pressure code. However, in order to obtain the pipe reliability, a probability distribution of the burst pressure should be provided. This study is concerned with estimating the burst pressure distribution using Monte Carlo simulation. A response surface method is employed to represent the distribution parameter as a model of the corrosion defect size. Results: The experimental results suggest that the normal or Weibull distribution should be suitable as the probability distribution of the burst pressure. In particular, it was shown that the probability distribution parameters can be well predicted by using the depth and length of the corrosion defect. Conclusion: Given a corrosion defect on the pipe, its corresponding burst pressure distribution can be provided at instant. Subsequently, a reliability assessment of the pipe is conducted as well.

• Transactions of the Korean Society of Pressure Vessels and Piping
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• v.17 no.1
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• pp.28-35
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• 2021

The flow accelerated corrosion (FAC) is one of significant aging and degradation mechanism and can affect structural integrity of CANDU feeder pipes. Pipe burst can occur under normal operation pressure (min. 10 MPa) if wall-thinning of the feeder pipe due to FAC is accumulated. Previous studies considered simple shapes of feeder pipe with local wall-thinning in order to conservatively assess structural integrity of wall-thinned feeder pipe. In this paper, a new FE model is developed, having an actual shape of the feeder pipe (double bent) as well as the actual wall-thinning shape and location based on the in-service inspection result. Then, the burst pressure assessment of the wall-thinned feeder pipe is performed using lower bound limit load analysis considering elastic-perfectly plastic material. In addition, an improved formulation to predict the burst pressure of the wall-thinned feeder pipe is presented and the safety margin is compared with an existing assessment method.

• Journal of the Korean Society of Safety
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• v.16 no.4
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• pp.39-46
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• 2001

It is noted that KS D 3507 pipe steel has several problems when it is used as a city gas pipe at medium pressure. So new pipe steel, KS D 3631, was developed in order to be used as a pipe for medium and low pressure and now it is being substituted for D 3507. In this study, several mechanical tests, such as tensile test, microhardness test, and Charpy impact test were conducted to get material properties of D 3507 and D 3631 pipe steels. And also microstructures at the weld and heat affected zones were observed for the two materials. From the Charpy test results $K_{IC}/$ was estimated for the upper and lower shelf and the critical crack length is calculated for supposed axial semi-elliptical surface cracks. And the burst pressure is estimated as a function of wear depth for a defective D 3631 pipe by using the finite element method. The burst pressure is also calculated for pipes with an axial crack by using the published equations.

• Proceedings of the KSME Conference
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• 2004.04a
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• pp.222-227
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• 2004

The failure assessment for corroded pipeline has been considered with the full scale burst test and the finite element analysis. The burst tests were conducted on 762 mm diameter, 17.5 mm wall thickness and API 5L X65 pipe that contained specially manufactured rectangular corrosion defect. The failure pressure for corroded pipeline was measured by burst testing and classified with respect to corrosion sizes and corroded regions - the body, the girth weld and the seam weld of pipe. Finite element analysis was carried out to derive failure criteria of corrosion defect on the pipe. A series of finite element analyses were performed to obtain a limit load solution for corrosion defects on the basis of burst test. As a result, the criteria for failure assessment of corrosion defect within the body, the girth weld and the seam weld of API 5L X65 gas pipeline were proposed.

• Journal of Korean Society of Water and Wastewater
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• v.37 no.6
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• pp.347-361
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• 2023

Water utilities are making various efforts to reduce water losses from water networks, and an essential part of them is to recognize the moment when a pipe burst occurs during operation quickly. Several physics-based methods and data-driven analysis are applied using real-time flow and pressure data measured through a SCADA system or smart meters, and methodologies based on machining learning are currently widely studied. Water utilities should apply various approaches together to increase pipe burst detection. The most intuitive and explainable water balance method and its procedure were presented in this study, and the applicability and detection performance were evaluated by applying this approach to water supply pipelines. Based on these results, water utilities can establish a mass balance-based pipe burst detection system, give a guideline for installing new flow meters, and set the detection parameters with expected performance. The performance of the water balance analysis method is affected by the water network operation conditions, the characteristics of the installed flow meter, and event data, so there is a limit to the general use of the results in all sites. Therefore, water utilities should accumulate experience by applying the water balance method in more fields.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.26 no.1
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• pp.203-210
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• 2002

The transmission pipeline industry spends many millions of dollars annually performing inline inspections, excavating sites of possible corrosion, and repairing or replacing damaged sections of pipe. New criteria fur evaluation of the integrity of corroded pipe have been developed in recent years to help in controlling these costs. These new criteria vary widely in their estimates of integrity and the most appropriate criterion fur a given pipeline is net always clear. This paper presents an overview, comparison and evaluation of acceptability criteria for corrosion deflects in pipelines. By full scale burst tests, this paper has assessed the relative accuracy of each of theses criteria in predicting burst pressure. Many of the criteria appear to be excessively conservative and indicate that deflects must be repaired when none is needed, based upon burst test data.

• Proceedings of the KSME Conference
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• 2001.06a
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• pp.339-344
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• 2001

The transmission pipeline industry spends many millions of dollars annually performing inline inspections, excavating sites of possible corrosion, and repairing or replacing damaged sections of pipe. New criteria for evaluation the integrity of corroded pipe have been developed in recent years to help in controlling these costs. These new criteria vary widely in their estimates of integrity and the most appropriate criterion for a given pipeline is not always clear. This paper presents an overview, comparison and evaluation of acceptability criteria for corrosion defects in pipelines. By full scale burst tests, this paper have assessed the relative accuracy of each of theses criteria in predicting failure and remaining strength. Many of the criteria appear to be excessively conservative and indicate that defects must be repaired when none is needed, based upon burst test data.