An overview of leaks and intrusion for different pipe materials and failures

Rodríguez, José de Jesús Mora; Delgado-Galván, Xitlali; Ramos, Helena M.; Jiménez, Petra Amparo López

doi:10.1080/1573062x.2012.739630

Cited by 40 publications

(21 citation statements)

References 19 publications

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“…Early studies have shown that the flow through a leak opening is related to the pressure raised to an exponent that varies typically from 0.5 to 2.5 depending on: the material of the pipe, the shape of the leak and the system pressure [6]. Recent studies by many researchers on various pipe materials and leak configurations support the observation under both leakage [7][8][9][10][11][12][13][14][15] and intrusion [5,16]. Regarding the amendment to the equation, the effects of orifice shape and size on the orifice discharge coefficient has been investigated [17,18].…”

Section: Introductionmentioning

confidence: 95%

“…However, as will be shown, estimating the volume of intrusion based on the conventional orifice equation that ignores the effect of the main pipe flow velocity may underestimate the volume of intrusion and the risk to public health. Research into accurately assessing the leakage and intrusion rates through cracked water pipes has attracted increasing attention [5].…”

Section: Introductionmentioning

confidence: 99%

“…The fact that leakage and intrusion through cracks in the pipe wall do not necessarily follow the standard orifice equation (the discharge flow varies with the square root of pressure difference across the orifice) has been widely recognized [5]. Early studies have shown that the flow through a leak opening is related to the pressure raised to an exponent that varies typically from 0.5 to 2.5 depending on: the material of the pipe, the shape of the leak and the system pressure [6].…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Impact of Main Pipe Flow Velocity on Leakage and Intrusion Flow: An Experimental Study

Shao

Yao

Gong

et al. 2019

Water

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The classic orifice equation is commonly used to calculate the leakage and intrusion rate for pressurized pipelines with cracks on the pipe wall. The conventional orifice equation does not consider the effect of the flow velocity in the main pipe, and there is a lack of studies on this matter. For this technical note, the influence of the main pipe flow velocity on the outflow and inflow through a crack on the pipe wall was studied in the laboratory. The experimental results show that the impact of the main pipe flow velocity can be significant. When the pressure difference across the orifice was constant, with the increase of the main pipe flow velocity, the outflow velocity increased, but the contraction area of the jet and the outflow discharge coefficient decreased. By comparing orifices with different shapes, it was found that the discharge from the circumferential crack was most sensitive to the main pipe flow velocity. In addition, the main pipe flow promoted the orifice inflow. When the pressure difference across the orifice was constant, with the increase of the main pipe flow velocity, the inflow discharge coefficient increased, which is the opposite pattern to that of the orifice outflow.

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Section: Introductionmentioning

confidence: 95%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Impact of Main Pipe Flow Velocity on Leakage and Intrusion Flow: An Experimental Study

Shao

Yao

Gong

et al. 2019

Water

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“…Moreover, in the presence of low or negative pressure in the distribution network, leaks represent vulnerable points of interaction between the environments inside and outside the pipe, thus allowing contaminant intrusions (Lindley and Buchberger 2002;Collins and Boxall 2013;Mora-Rodriguez et al 2014;Fontanazza et al 2015). These operational conditions are accentuated in systems with intermittent supply (De Marchis et al 2010Freni et al 2014), where water network experienced cyclically empting and filling process and, as a result, pipes integrity could be further compromised.…”

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confidence: 96%

Experimental Evidence of Leaks in Elastic Pipes

Marchis

Fontanazza

Freni

et al. 2016

Water Resour Manage

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Several studies have been carried out in recent decades to establish a relationship between total head and leaks. In literature, the leakage governing equations have been analysed in light of pipe materials, water head, leak dimension or shape. Most of these contributions questioned the classical Torricelli equation, demonstrating through experimental evidence that the classical orifice law can give unsatisfactory results. Nevertheless, starting from the Torricelli equation, other exponential or linear governing equations have been proposed as mathematical models able to reproduce the leakages in water distribution systems (WDSs). To investigate the validity of the proposed governing equations, an experimental campaign was carried out by means of a water distribution network composed of approximately 500 m of polyethylene pipes. The experiments were designed to investigate the effects of leak area and pipe rigidity on discharge. Furthermore, the effect of leak size enlargement with water head was analysed. Finally, the proposed research contributes to the population of a database for estimating the coefficients of head-discharge relationships.

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“…Farley and Trow (2003) reported that the leakage rate through WDSs represents 50% of the total water produced and might reach 80% for some networks. Mora et al (2014) pointed out that leak discharge is dependent on soil type, water quality, specifications and construction quality, materials, infrastructure age, operational practices and maintenance. In addition, leaks can occur as a consequence of a cross-section crack, crushing and longitudinal cracks.…”

Section: Introductionmentioning

confidence: 99%

Numerical investigation of leakage behaviour in long radius elbows

Darweesh

Hussien

2020

WSA

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This paper focuses on the relationship between leakage opening areas and pressure heads for 90° long radius elbows under elastic limits using finite element analysis (SAP 2000). The results indicate that leakage opening areas grow linearly as the system pressure increases and the relation is described by the pressure–area slope (M). A sensitivity study was performed to show the effect of various parameters on M, as well as the leakage exponent (N). It was found that elbow internal diameter has the largest influence on the pressure–area slope, followed by the modulus of elasticity and finally elbow wall thickness. The longitudinal stress and Poisson’s ratio have a negligible effect on M. Furthermore, leak quantity is related to the pressure raised to a power ranging from 0.495 to 0.592. Regression analysis was used to derive an empirical equation to predict the pressure–area slope of round holes within elbows with different properties.

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An overview of leaks and intrusion for different pipe materials and failures

Cited by 40 publications

References 19 publications

Impact of Main Pipe Flow Velocity on Leakage and Intrusion Flow: An Experimental Study

Impact of Main Pipe Flow Velocity on Leakage and Intrusion Flow: An Experimental Study

Experimental Evidence of Leaks in Elastic Pipes

Numerical investigation of leakage behaviour in long radius elbows

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