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

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.

2018 ◽  
Author(s):  
Karel van Laarhoven ◽  
Ina Vertommen ◽  
Peter van Thienen

Abstract. Genetic algorithms can be a powerful tool for the automated design of optimal drinking water distribution networks. Fast convergence of such algorithms is a crucial factor for successful practical implementation at the drinking water utility level. In this technical note, we therefore investigate the performance of a suite of genetic variators that was tailored to the optimisation of a least-cost network design. Different combinations of the variators are tested in terms of convergence rate and the robustness of the results during optimisation of the real world drinking water distribution network of Sittard, the Netherlands. The variator configurations that reproducibly reach the furthest convergence after 105 function evaluations are reported. In the future these may aid in dealing with the computational challenges of optimizing real world networks.


2018 ◽  
Vol 11 (2) ◽  
pp. 101-105
Author(s):  
Karel van Laarhoven ◽  
Ina Vertommen ◽  
Peter van Thienen

Abstract. Genetic algorithms can be a powerful tool for the automated design of optimal drinking water distribution networks. Fast convergence of such algorithms is a crucial factor for successful practical implementation at the drinking water utility level. In this technical note, we therefore investigate the performance of a suite of genetic variators that was tailored to the optimization of a least-cost network design. Different combinations of the variators are tested in terms of convergence rate and the robustness of the results during optimization of the real-world drinking water distribution network of Sittard, the Netherlands. The variator configurations that reproducibly reach the furthest convergence after 105 function evaluations are reported. In the future these may aid in dealing with the computational challenges of optimizing real-world networks.


Water ◽  
2021 ◽  
Vol 13 (17) ◽  
pp. 2391
Author(s):  
Karel van Laarhoven ◽  
Jip van Steen ◽  
Frank van der Hulst ◽  
Hector Hernandez Delgadillo

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.


2008 ◽  
Vol 8 (4) ◽  
pp. 421-426
Author(s):  
J. Menaia ◽  
M. Benoliel ◽  
A. Lopes ◽  
C. Neto ◽  
E. Ferreira ◽  
...  

Concerns arise from the possible occurrence of pathogens in drinking water pipe biofilms and storage tank sediments. In these studies, biofilm samples from pipes and sediments from storage tanks of the Lisbon drinking water distribution system were analyzed. Protein determinations and heterotrophic counts on pipe biofilm samples were used to assess the Lisbon network sessile colonization intensity and distribution. Indicator and pathogenic microorganisms were analyzed in pipe biofilm samples, as well as in storage tanks biofilm and sediments, by using cultural methods and PCR, to assess risks. Results have shown that the Lisbon network sessile colonization is relatively weak in intensity. In addition, no meaningful hazards were apparent for both the network biofilm and the storage tanks biofilm and sediments.


2019 ◽  
Vol 2 (1) ◽  
pp. 11 ◽  
Author(s):  
Arif Susanto ◽  
Purwanto Purwanto ◽  
Agus Hadiyarto

Abstract:. The requirement of consumed drinking water so that it does not create disturbance to public health is that it needs a quality monitoring. Water fluoridation in Tembagapura City aims to reach its concentration level toward certain safe level, and it can provide maximum benefits for dental health. Analysis and simulation methods using EPAnet software. The results of hydrolic simulation and water quality for fluoride concentration of each node and link in the drinking water distribution network system have changed in every time change following the drinking water distribution segment. From hydraulic simulations, especially for head and flow at separate points, it consists of simultaneous solution in flow equivalence for every junction and headloss relationship in every link of network as a result of hydraulic balancing. New segment will be made at the end of each link that receives inflow from a node if the quality of the new node is different from the link in the last segment. Every pipe in network contains singular segment where the water quality is in line with the preliminary quality stated in the preliminary node. With the availability of hydraulic model and water quality for fluoride concentration, a further research can be conducted for chlorine decay, growth of by product i.e. Trihalomethans (THMs) as well as water age simultaneously in drinking water supply systems in Tembagapura City.  Keyword: EPAnet, distribution network, fluoride concentration. Abstrak: Persyaratan kualitas air minum yang dikonsumsi masyarakat agar tidak menimbulkan gangguan kesehatan, maka penyelenggara air minum perlu melakukan pemantauan kualitasnya. Fluoridasi air di Kota Tembagapura ditujukan untuk mencapai tingkat konsentrasi fluoride pada level tertentu yang aman dan dapat memberikan manfaat maksimal bagi kesehatan gigi. Metode analisis dan simulasi menggunakan perangkat lunak EPAnet. Hasil simulasi hidrolis dan kualitas air untuk konsentrasi fluoride pada setiap node dan link pada sistem jaringan distribusi air minum berubah pada setiap perubahan waktu mengikuti segmen distribusi air minum tersebut. Dari simulasi hidrolis, khusus untuk head dan aliran pada titik yang terpisah meliputi penyelesaian secara simultan dalam persamaan aliran untuk tiap sambungan (junction), dan hubungan headloss pada setiap link pada jaringan sebagai akibat dari hydrolic balancing. Segmen baru terbentuk pada akhir dari setiap link yang menerima inflow dari sebuah node, jika kualitas node baru berbeda dari link pada segmen terakhir. Setiap pipa dalam jaringan mengandung segmen tunggal, di mana kualitas air sebanding dengan kualitas awal yang ditetapkan di node awal. Dengan tersedianya model hidrolis dan kualitas air untuk konsentrasi fluoride, maka dapat dilakukan penelitian lanjutan untuk peluruhan klorin, pertumbuhan by product yaitu trihalomethans (THMs) serta usia air secara simultan pada sistem penyediaan air minum di Kota Tembagapura.Kata Kunci: EPAnet, jaringan distribusi, konsentrasi fluoride.


2018 ◽  
Vol 7 (2.1) ◽  
pp. 92
Author(s):  
Dharmendra Kumar Tyagi ◽  
Mrinmoy Majumder ◽  
Chander Kant ◽  
Ashish Prabhat Singh

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%. 


2012 ◽  
Vol 12 (5) ◽  
pp. 580-587 ◽  
Author(s):  
Stephen Mounce ◽  
John Machell ◽  
Joby Boxall

Safe, clean drinking water is a foundation of society and water quality monitoring can contribute to ensuring this. A case study application of the CANARY software to historic data from a UK drinking water distribution system is described. Sensitivity studies explored appropriate choice of algorithmic parameter settings for a baseline site, performance was evaluated with artificial events and the system then transferred to all sites. Results are presented for analysis of nine water quality sensors measuring six parameters and deployed in three connected district meter areas (DMAs), fed from a single water source (service reservoir), for a 1 year period and evaluated using comprehensive water utility records with 86% of event clusters successfully correlated to causes (spatially limited to DMA level). False negatives, defined by temporal clusters of water quality complaints in the pilot area not corresponding to detections, were only approximately 25%. It was demonstrated that the software could be configured and applied retrospectively (with potential for future near real time application) to detect various water quality event types (with a wider remit than contamination alone) for further interpretation.


2012 ◽  
Vol 15 (3) ◽  
pp. 666-675 ◽  
Author(s):  
M. Ferrante ◽  
C. Massari ◽  
E. Todini ◽  
B. Brunone ◽  
S. Meniconi

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.


Sign in / Sign up

Export Citation Format

Share Document