Leak behaviour in pressurized PVC pipes

2013 ◽  
Vol 13 (4) ◽  
pp. 987-992 ◽  
Author(s):  
M. Ferrante ◽  
C. Massari ◽  
B. Brunone ◽  
S. Meniconi
Keyword(s):  
Distribution Systems ◽  
Water Distribution ◽  
Numerical Models ◽  
Pipe Material ◽  
Correct Definition ◽  
Total Head ◽  
Definition Of ◽  
The University ◽  
The Relationship ◽  
Strain Measures

The correct definition of the leak law, i.e. the relationship between the leak outflow, the total head at the leak and other relevant parameters such as the pipe material, can seriously affect the accuracy of the numerical models used for the management of water distribution systems, either if they are used to forecast the leakage reduction by pressure management or to locate and size the leaks within an inverse analysis. In recent decades the use of the classical Torricelli or orifice equation has been questioned in the sense that some experimental results clearly demonstrated that the assumption of a leak outflow proportional to the square root of the head drop can yield unsatisfactory results. To investigate this behaviour, an experimental activity has been carried out at the Water Engineering Laboratory of the University of Perugia, Italy. Part of the results of the carried out tests are presented in this paper for a leak in a polyvinyl chloride (PVC) pipe. Leak laws based on the assumption of a leak area variation with the pressure are compared and validated by strain measures close to the leak.

scholarly journals On the Calibration of the Mathematical Laws for the Water Loss Estimation in Water Distribution Network

10.29007/rk2f ◽  
2018 ◽  
Author(s):  
Mauro De Marchis ◽  
Barbara Milici
Keyword(s):  
Water Distribution ◽  
Water Distribution Network ◽  
Distribution Networks ◽  
Polyethylene Pipes ◽  
Experimental Campaign ◽  
Total Head ◽  
Definition Of ◽  
The University ◽  
The Relationship ◽  
Model Water

The definition of the relationship between the leak outflow, the total head at the leak and other relevant parameters such as the pipe stiffness, the leak dimension and shape has been object of extensive studies in recent decades. The use of the Torricelli equation has been questioned, because some experimental results showed that it can yield unsatisfactory results, and other formulations have been suggested to model water leakages in water distribution networks (WDNs). To investigate the effectiveness of the formulations suggested by different authors, an experimental campaign was carried out at the Environ- mental Hydraulic Laboratory of the University of Enna (Italy) for leaks of different shape and size in polyethylene pipes.

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 Hydraulic Performance Analysis and Modeling of Water Supply Distribution System of Addis Ababa Science and Technology University, Ethiopia

2020 ◽  
Author(s):  
Chalchisa Milkecha ◽  
Habtamu Itefa
Keyword(s):  
Water Supply ◽  
Water Demand ◽  
Distribution System ◽  
Distribution Systems ◽  
Water Distribution ◽  
Addis Ababa ◽  
Science And Technology ◽  
Hydraulic Performance ◽  
Alternative Methods ◽  
The University

This study was conducted generally by aiming assessment of the hydraulic performance of water distribution systems of Addis Ababa Science and Technology University (AASTU). In line with the main objective, this study addressed, (1) pinpointing problems of existing water supply versus demand deficit (2) evaluating the hydraulic performance of water distribution system using water GEMS and (3) recommended alternative methods for improving water demand scenarios. The University’s water supply distribution network layout was a looped system and the flow of water derived by both gravity and pressurized system. The gravity flow served for the academic and administrative staffs whereas the pressurized system of the network fed the students dormitories, cafeteria’s etc. The study revealed the existence of unmet minimum pressure requirement around the student dormitories which accounts 25.64% below the country’s building code standard during the peak hour consumption. The result of the water demand projection showed an increment of 2.5 liter per capita demand (LPCD) in every five years. Hence, first, the university’s water demand was projected and then hydraulic parameters such as; pressure, head loss and velocity were modeled for both the existing and the improved water supply distribution. The finding of the study was recommended to the university’s water supply project and institutional development offices for its future modification and rehabilitation works.

scholarly journals Minimum Night Flow Analysis and Application of the Fixed and Variable Area Discharges Model for Characterizing Leakage in the Gorino Ferrarese (FE-Italy) District

2020 ◽  
Vol 2 (1) ◽  
pp. 8
Author(s):  
Irene Marzola ◽  
Stefano Alvisi ◽  
Marco Franchini
Keyword(s):  
Time Series ◽  
Distribution Systems ◽  
Water Distribution ◽  
Flow Analysis ◽  
Water Utilities ◽  
Smart Meters ◽  
Minimum Night Flow ◽  
Major Interest ◽  
The Relationship ◽  
District Metered Area

Leakage in water distribution systems is an important issue and of major interest for water utilities. In this study, the Minimum Night Flow (MNF) method to quantify the amount of water lost and the equations representing the relationship between pressure and leakage in power and FAVAD (Fixed and Variable Area Discharge) forms were applied to a District Metered Area (DMA) located in Gorino Ferrarese (FE, Italy) equipped with smart meters. The analysis carried out by exploiting the collected time series of user water consumption, DMA inflow, and pressure highlighted that: (a) the MNF method can lead to significant inaccuracy in leakage estimation in the presence of users with irregular consumptions, when based on literature values, and (b) the estimation of the parameters of the power and FAVAD equation is highly affected by the number and types of observed data used.

Kinetic aspects of biofilm formation on surfaces exposed to drinking water

1995 ◽  
Vol 32 (8) ◽  
pp. 61-65 ◽  
Author(s):  
D. van der Kooij ◽  
H. S. Vrouwenvelder ◽  
H. R. Veenendaal
Keyword(s):  
Drinking Water ◽  
Biofilm Formation ◽  
Distribution Systems ◽  
Water Distribution ◽  
Formation Rate ◽  
Water Distribution Systems ◽  
Acetate Concentration ◽  
Drinking Water Distribution Systems ◽  
Drinking Water Distribution ◽  
The Relationship

Biofilm formation in drinking water distribution systems should be limited to prevent the multiplication of undesirable bacteria and other organisms. Certain types of drinking water with an AOC concentration below 10 μg of acetate-C eq/l can support the growth of Aeromonas. Therefore, the effect of acetate at a concentration of 10 μg of C/l on the biofilm formation rate (BFR) of drinking water with a low AOC concentration (3.2 μg C/l) was determined. Drinking water without acetate had a BFR of 3.9 pg ATP/cm2.day, whereas a BFR value of 362 pg ATP/cm2.day was found with acetate added. These data indicate that a low acetate concentration strongly affects biofilm formation, and that only a small fraction of AOC is available for biofilm formation. Aeromonads did not multiply in the biofilm despite their ability to grow at a concentration of 10 μg of acetate-C/l. Further investigations are needed to elucidate the relationship between substrate concentration and biofilm formation in drinking water distribution systems and the growth of undesirable bacteria in these biofilms.

scholarly journals Multivariate data mining for estimating the rate of discolouration material accumulation in drinking water distribution systems

2015 ◽  
Vol 18 (1) ◽  
pp. 96-114 ◽  
Author(s):  
S. R. Mounce ◽  
E. J. M. Blokker ◽  
S. P. Husband ◽  
W. R. Furnass ◽  
P. G. Schaap ◽  
...  
Keyword(s):  
Data Mining ◽  
Distribution Systems ◽  
Water Distribution ◽  
Cross Validation ◽  
Local Level ◽  
Multivariate Data ◽  
Water Distribution Systems ◽  
Pipe Material ◽  
Data Set ◽  
Regeneration Rate

Particulate material accumulates over time as cohesive layers on internal pipeline surfaces in water distribution systems (WDS). When mobilised, this material can cause discolouration. This paper explores factors expected to be involved in this accumulation process. Two complementary machine learning methodologies are applied to significant amounts of real world field data from both a qualitative and a quantitative perspective. First, Kohonen self-organising maps were used for integrative and interpretative multivariate data mining of potential factors affecting accumulation. Second, evolutionary polynomial regression (EPR), a hybrid data-driven technique, was applied that combines genetic algorithms with numerical regression for developing easily interpretable mathematical model expressions. EPR was used to explore producing novel simple expressions to highlight important accumulation factors. Three case studies are presented: UK national and two Dutch local studies. The results highlight bulk water iron concentration, pipe material and looped network areas as key descriptive parameters for the UK study. At the local level, a significantly increased third data set allowed K-fold cross validation. The mean cross validation coefficient of determination was 0.945 for training data and 0.930 for testing data for an equation utilising amount of material mobilised and soil temperature for estimating daily regeneration rate. The approach shows promise for developing transferable expressions usable for pro-active WDS management.

scholarly journals A Modern Approach to the Formation of a Terminological System in the Field of Fire Protection

2021 ◽  
Vol 320 ◽  
pp. 02006
Author(s):  
Yuriy Naumov ◽  
Nikolai Smirnov ◽  
Andrei Pekhotikov ◽  
Ol’ga Zuban’ ◽  
Marina Gravit
Keyword(s):  
Fire Protection ◽  
Fire Retardant ◽  
Manufacturing Processes ◽  
Modern Approach ◽  
Correct Definition ◽  
Definition Of ◽  
The Relationship

The paper considers a variant of combining the terms used in the field related to the study of fire protection means into a terminological system. The correct definition of terms is also crucial in technological and manufacturing processes. That is why it was decided to form and describe the terminological system in the field of fire protection and fire retardant materials. The terms in terminological system are to be related between each other, and to be expressing the relationship between the concepts that they denote. Such a system does not yet exist in the field of fire protection, so the authors aim was to create its basis. The types of relations between the terms defining the structure of the system have been established, a diagram that illustrates the distribution and coordination of terms in the system has been developed. On the basis of the relations between the terms established in the terminological system, the existing definitions were assessed with subsequent, if necessary, adjustments to meet the requirements for the terms of unambiguity, compliance with the expressed concept and elimination of synonymy.

Drinking water pipe biofilm: present knowledge, concepts and significance

2004 ◽  
Vol 4 (2) ◽  
pp. 115-124 ◽  
Author(s):  
J. Menaia ◽  
E. Mesquita
Keyword(s):  
Drinking Water ◽  
Distribution Systems ◽  
Water Distribution ◽  
Flow Dynamics ◽  
Pipe Material ◽  
Water Pipe ◽  
Drinking Water Distribution Systems ◽  
Drinking Water Distribution ◽  
Development Structure ◽  
Microbial Regrowth

Biofilms invariably colonize drinking water distribution systems with intensities and patterns governed by the habitat's environment. Water temperature and flow dynamics, nutrient availability, disinfectant residual and pipe material determine their development, structure and composition. Drinking water pipe biofilms control microbial regrowth and are a possible source of pathogens. However, these are possibly released at levels that do not generally impart hazards to healthy drinking water consumers. A deeper understanding of drinking water biofilms microbial ecology must be achieved before this issue can be adequately assessed.

scholarly journals Regverdiging van die sondaar: Martin Luther se teologiese definisie van die mens soos uiteengesit in die Disputatio de homine van 1536, stelling 32

2017 ◽  
Vol 73 (1) ◽  
Author(s):  
Gabriël M.J. Van Wyk
Keyword(s):  
Academic Career ◽  
Martin Luther ◽  
Protestant Reformation ◽  
The Face ◽  
The Subject ◽  
Essential Resource ◽  
Definition Of ◽  
The University ◽  
The Relationship ◽  
Theology And Philosophy

Disputations were a fixture of Martin Luther’s academic career. Luther participated regularly in disputations. It was an important communicative vehicle through which he developed and expressed his theology. The well-known 95 theses are a case in point. Luther’s career as a disputator was impressive. Several of his most influential disputations were explicitly intended for consideration by his academic and ecclesiastical colleagues, but the majority of his disputations took place as a curricular exercise at the University of Wittenberg. The purpose of these disputations was pedagogical and polemical. Luther deployed the same tools for his defence of proper doctrine that were at the centre of the Protestant reformation in the face of objections. The disputatio de homine is a systematic summary of Luther’s anthropology. It incorporates the doctrine of justification as the theological definition of man. It treats the subject within the context of the relationship between theology and philosophy, and reflects upon the new language of theology. The disputatio de homine provides an essential resource for the study of Luther’s anthropology and the doctrine of justification.

Sign in / Sign up

Export Citation Format

Share Document