scholarly journals CT Scans of Asbestos Cement Pipes as a Reference for Condition Assessment of Water Mains

Water ◽  
2021 ◽  
Vol 13 (17) ◽  
pp. 2391
Author(s):  
Karel van Laarhoven ◽  
Jip van Steen ◽  
Frank van der Hulst ◽  
Hector Hernandez Delgadillo
Keyword(s):  
Water Distribution ◽  
Poor Performance ◽  
Water Distribution Network ◽  
Condition Assessment ◽  
Water Utilities ◽  
Detailed Knowledge ◽  
Pipe Material ◽  
Detailed Measurement ◽  
Asbestos Cement ◽  
Water Mains

The water distribution network of The Netherlands contains around 30,000 km of asbestos cement (AC) pipes, which constitutes around 25% of the total network. As a pipe material, AC has a relatively poor performance, and therefore is a high priority for renewal. To help decide an effective order of replacement, the water utilities need condition assessment techniques that help them determine which pipes have the highest risk of failure. In the presented work, X-ray computed tomography (CT) was used to measure the degradation of AC pipes taken out of the field. These scans provide a description of the pipe degradation with unmatched detail. The results are compared with strength tests performed on the same pipes, revealing that detailed knowledge of the complete pipe degradation is more important than previously assumed. Moreover, comparison of the CT results to those of a commercial, non-destructive inspection technique was used as a new avenue for validation of this technique, demonstrating its future usefulness for attaining the detailed measurement of pipe degradation required by water utilities.

scholarly journals CT Scans of Asbestos Cement Pipes to Support the Development of Better Condition Assessments

2020 ◽  
Vol 2 (1) ◽  
pp. 11
Author(s):  
Karel van Laarhoven ◽  
Claudia Quintiliani
Keyword(s):  
Water Distribution ◽  
Water Distribution Network ◽  
Ct Scans ◽  
Pipe Material ◽  
Water Utility ◽  
Asbestos Cement ◽  
Drinking Water Distribution ◽  
X Ray Computed ◽  
Condition Assessments ◽  
Inspection Techniques

The Dutch drinking water distribution network consists roughly of 25% (around 30,000 km) asbestos cement pipes. This pipe material has a relatively high priority to be renewed and therefore received quite some attention when it comes to the development of condition assessments that help water utility experts to prioritize which of these pipes to replace first. In the presented work, X-ray computed tomography (CT) was used to measure the degradation of the asbestos cement (AC) pipes taken out of the field. The CT scans provide a highly detailed view of the pipe degradation. The insight provided by these images poses several questions with respect to some of the core assumptions of the condition models currently in use. Moreover, the comparison of CT results to those of non-destructive, in-line inspection techniques will provide a new avenue for the validation of these techniques and their usefulness for the Dutch water utilities.

scholarly journals Estimation of hazen williams’s constant for a residential water distribution network; GMDH and PSO approach

2018 ◽  
Vol 7 (2.1) ◽  
pp. 92
Author(s):  
Dharmendra Kumar Tyagi ◽  
Mrinmoy Majumder ◽  
Chander Kant ◽  
Ashish Prabhat Singh
Keyword(s):  
Fluid Flow ◽  
Pipe Flow ◽  
Water Distribution ◽  
Water Distribution Network ◽  
Pipe Material ◽  
Pipe Network ◽  
Closed Channel ◽  
Computation Techniques ◽  
Flow Potential ◽  
Residential Water

Hazen-William equation is used to estimate the Fluid flow in closed channel. There are various models for estimation of pipe flow, however the accuracy and reliability of models varies due to the empirical nature of the Hazen-William constant .the applicability of model also become constrained due to the dependency of constant on pipe material, dimension and flow potential. Different type of pipeline arranged in different Networks will require different value of the constant and is generally retrieved from the data collected for the pipe network. The case dependency of the model has makes the model erroneous and often subjective that is why the present study tries to propose a model which can be used for any network where the output will depend upon the inputs. In this aspect the soft computation techniques: - GMDH and PSO was utilized in an unconventional way to establish the value of CHW =f (H, L, V, D).  According to result the GMDH becomes the better model than the PSO where the accuracy is about 76.315%. 

scholarly journals Experimental investigation of leak hydraulics

2012 ◽  
Vol 15 (3) ◽  
pp. 666-675 ◽  
Author(s):  
M. Ferrante ◽  
C. Massari ◽  
E. Todini ◽  
B. Brunone ◽  
S. Meniconi
Keyword(s):  
Distribution Systems ◽  
Water Distribution ◽  
Network Models ◽  
Water Distribution Network ◽  
Experimental Tests ◽  
Pressure Control ◽  
Pipe Material ◽  
Governing Equations ◽  
The One ◽  
Definition Of

In recent decades the hydraulics of leaks, i.e. the definition of the relationships linking the hydraulic quantities in pipes with leaks, has received increasing attention. On the one hand, the definition of the relationship between the leak outflow and the relevant parameters – e.g. the leak area and shape, the pressure inside the pipe and outside the leak, and the pipe material – is crucial for pressure control and inverse analysis techniques. On the other hand, if the effect of the leakage on the governing equations is not taken into account, i.e. the loss of the flow axial momentum is not considered, significant errors can be introduced in the simulation of water distribution systems. In this paper, the governing equations for a pipe with a leak are derived. The basic equations, obtained within different approaches, are presented in a consistent formulation and then compared with the results of some experimental tests. The leak jet angle and other major features of the results are analysed. The estimated values of the parameters can be used in the water distribution network models when pipes with a diffuse leakage are considered.

scholarly journals I-WARP: Individual Water mAin Renewal Planner

2010 ◽  
Vol 3 (1) ◽  
pp. 71-77 ◽  
Author(s):  
Y. Kleiner ◽  
B. Rajani
Keyword(s):  
Research Council ◽  
National Research Council ◽  
Water Utilities ◽  
Pipe Material ◽  
Mathematical Approach ◽  
Structural Deterioration ◽  
Dynamic Factors ◽  
Water Mains ◽  
Subsequent Failure

Abstract. I-WARP is based upon a nonhomogeneous Poisson approach to model breakage rates in individual water mains. The structural deterioration of water mains and their subsequent failure are affected by many factors, both static (e.g., pipe material, pipe size, age (vintage), soil type) and dynamic (e.g., climate, cathodic protection, pressure zone changes). I-WARP allows for the consideration of both static and dynamic factors in the statistical analysis of historical breakage patterns. This paper describes the mathematical approach and demonstrates its application with the help of a case study. The research project within which I-WARP was developed, was jointly funded by the National Research Council of Canada (NRC), and the Water Research foundation (formerly known as the American Water Works Association Research Foundation – AwwaRF) and supported by water utilities from USA and Canada.

scholarly journals Comparison of four models to rank failure likelihood of individual pipes

2011 ◽  
Vol 14 (3) ◽  
pp. 659-681 ◽  
Author(s):  
Yehuda Kleiner ◽  
Balvant Rajani
Keyword(s):  
Water Distribution ◽  
Distribution Networks ◽  
Classification Model ◽  
Pipe Material ◽  
Homogeneous Poisson Process ◽  
Model Based ◽  
Water Mains ◽  
Natural Variations ◽  
Non Homogeneous Poisson Process ◽  
Subsequent Failure

The use of statistical methods to discern patterns of historical breakage rates and use them to predict water main breaks has been widely documented. Particularly challenging is the prediction of breaks in individual pipes, due to the natural variations that exist in all the factors that affect their deterioration and subsequent failure. This paper describes alternative models developed into operational tools that can assist network owners and planners to identify individual mains for renewal in their water distribution networks. Four models were developed and compared: a heuristic model, a naïve Bayesian classification model, a model based on logistic regression and finally a probabilistic model based on the non-homogeneous Poisson process (NHPP). These models rank individual water mains in terms of their anticipated breakage frequency, while considering both static (e.g. pipe material, diameter, vintage, surrounding soil, etc.) and dynamic (e.g. climate, operations, cathodic protection, etc.) effects influencing pipe deterioration rates.

scholarly journals I-WARP: individual water main renewal planner

2010 ◽  
Vol 3 (1) ◽  
pp. 25-41 ◽  
Author(s):  
Y. Kleiner ◽  
B. Rajani
Keyword(s):  
Research Council ◽  
National Research Council ◽  
Water Utilities ◽  
Pipe Material ◽  
Mathematical Approach ◽  
Structural Deterioration ◽  
Dynamic Factors ◽  
Water Mains ◽  
Subsequent Failure

Abstract. I-WARP is based upon a nonhomogeneous Poisson approach to model breakage rates in individual water mains. The structural deterioration of water mains and their subsequent failure are affected by many factors, both static (e.g., pipe material, pipe size, age (vintage), soil type) and dynamic (e.g., climate, cathodic protection, pressure zone changes). I-WARP allows for the consideration of both static and dynamic factors in the statistical analysis of historical breakage patterns. This paper describes the mathematical approach and demonstrates its application with the help of a case study. The research project within which I-WARP was developed, was jointly funded by the National Research Council of Canada (NRC), and the Water Research foundation (formerly known as the American Water Works Association Research Foundation – AwwaRF) and supported by water utilities from USA and Canada.

Model of leak inspection and repair of water distribution network

2001 ◽  
Vol 1 (2) ◽  
pp. 225-230 ◽  
Author(s):  
Y. Hosoi
Keyword(s):  
Water Distribution ◽  
Distribution Network ◽  
Water Distribution Network ◽  
Distribution Area ◽  
Water Supply Systems ◽  
Pipe Material ◽  
Water Leakage ◽  
Inspection Interval ◽  
Pipe Breakage ◽  
Supply Systems

Theories and policies for the maintenance and renewal of water supply systems are required. The occurrence of water distribution pipe breakage and water leakage is influenced by pipe material, size and age as well as soil characteristics and transportation. The water leakage has to be discovered as soon as possible from the viewpoint of minimizing water loss. However, it costs more to increase inspections for water leakage. In this study, the model to determine the optimal inspection interval for water leakage of the water distribution network was examined. The optimal inspection interval was estimated to minimize the total cost of inspection, pipe repair and lost water. The developed model was applied to a water distribution area whose water main is 486 kilometres long. The area was divided into sub-area of 250 metres square. Those sub-areas were classified into 6 groups according to pipe break rate. The optimal inspection interval was obtained for each group and its validity examined by numerical simulation.

Strategic Condition Assessment of the Water Distribution Network in Abu Dhabi

2013 ◽  
Author(s):  
Guy Cleveland ◽  
Sandra Rolfe-Dickinson ◽  
Jonathan Rogan ◽  
Punam Halai
Keyword(s):  
Water Distribution ◽  
Distribution Network ◽  
Water Distribution Network ◽  
Condition Assessment ◽  
Abu Dhabi

scholarly journals Study of the effect of pipe materials and mixing phenomenon on trihalomethanes formation and diffusion in a laboratory-scale water distribution network

2017 ◽  
Vol 18 (1) ◽  
pp. 183-192 ◽  
Author(s):  
Rojacques Mompremier ◽  
Óscar Arturo Fuentes Mariles ◽  
Kebreab Ghebremichael ◽  
Ana Elisa Silva Martínez ◽  
José Elías Becerril Bravo
Keyword(s):  
Residence Time ◽  
Water Distribution ◽  
Distribution Network ◽  
Water Distribution Network ◽  
Laboratory Scale ◽  
Pipe Material ◽  
Sampling Locations ◽  
The Impact ◽  
And Diffusion ◽  
Pipe Materials

Abstract The objective of this study was to evaluate the factors that affect the formation and diffusion of disinfection by-products, especially trihalomethanes (THM), in a laboratory-scale water distribution network constructed with three different pipe materials. Sampling locations were chosen on the basis of residence time, pipe material and mixing zone. Water samples were collected and analyzed for temperature, pH, total organic carbon, turbidity, free chlorine and THM. Experiments were carried out where two different flow directions at cross junctions were studied. It was observed that for incoming flow at 90° with varying flow rate, mixing was shown to be incomplete where inflows tend to bifurcate rather than mix completely. For two incoming flows in opposing direction (180°), solute mixing has shown to be perfect due to the collision of the fluid streams. The results demonstrated how THM concentration can greatly vary in the same water distribution network due to the impact of pipe material, residence time and the outcome of mixing at cross junctions.

scholarly journals Study of the variation of haloacetic acids in a simulated water distribution network

2018 ◽  
Vol 19 (1) ◽  
pp. 88-96
Author(s):  
Rojacques Mompremier ◽  
Óscar Arturo Fuentes Mariles ◽  
José Elías Becerril Bravo ◽  
Kebreab Ghebremichael
Keyword(s):  
Distribution System ◽  
Distribution Systems ◽  
Water Distribution ◽  
Water Distribution Network ◽  
Organic Content ◽  
Chlorine Concentration ◽  
Haloacetic Acids ◽  
Feed Water ◽  
Pipe Material ◽  
Pipe Materials

Abstract This paper presents the analysis of the variation of haloacetic acids (HAAs) for different pipe materials in a distribution system. The work involved an experimental study on a simulated distribution system assembled in the Hydraulic Laboratory of the Engineering Institute at the National Autonomous University of Mexico (Instituto de Ingeniería UNAM). Two different scenarios were investigated based on different pipe materials, variation of temperature and initial chlorine concentrations (4.0 and 4.5 mg/L). Feed water with varying amounts of organic content was dosed with varying amounts of chlorine concentration. Water samples were collected from different locations in the distribution system and analyzed for physicochemical properties and HAAs determination. The results of this research demonstrated that the concentration of HAAs in the different segments of the distribution systems varied depending on pipe material, initial chlorine concentration, pH, residence time and the presence of natural organic matter.

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