Consumption Change‐Induced Transients in a Water Distribution Network: Laboratory Tests in a Looped System

Abstract

In pipe networks, the pressure plays a key role and, in particular, pressure variations due to transients can induce additional stresses not only on pipes, but also on the other components, such as junctions and devices.Traditionally, in transmission mains attention is focused on the effects of a valve maneuver, carried out to set an appropriate discharge, or pump trip that can give rise to severe overpressures (Liou & Wylie, 2016;Meniconi et al., 2018;. Very different is the approach with respect to transients in water distribution networks (WDNs) which are the topic of this paper. Precisely, the effects of the transients in WDNs are often underestimated in the belief that such systems are always intrinsically self-protected against them. Such a conviction is based on the assumption that a large part of the generated pressure waves would exit through the consumers that, when active, behave as pressure relief valves. Thus, pipe breaks in WDNs are attributed to the large mean pressure or, in case the pressure regime is considered as appropriate, the inaccurate installation of pipes, additional loads due to traffic, and the large number of connections that undermine the integrity of the system. As a remedy against the large pressure regime and leakage, in WDNs the installation of pressure reducing valves (PRVs) is a common practice (e.g., Meniconi et al., 2017).Posed the question in these terms, in many cases it is arduous identifying the actual cause of the large leakage that characterizes only some parts of a WDN that exhibit no clear differences with respect to other ones in terms of pipe material, maintenance, external loads, as well as the pressure values, usually monitored at a low frequency. A possible explanation of such a feature could derive from a proper identification of the nature of the actually dangerous transients and the different exposure to them of individual parts of the considered WDN. With the aim of explaining the results achieved by this paper and pointing out the open questions and urgent matter to address, a literature review is offered below.Numerous papers analyze numerically the transient behavior of a WDN. More in details, the numerical papers deal with four main aspects: (a) the use of transients for detecting an anomaly (

Extending the Application of Connectivity Metrics for Characterizing the Dynamic Behavior of Water Distribution Networks

“…Some studies have shown that the response of the WDN to these forcing factors depends on its characteristics and, in particular, on the topological structure (i.e., network connectivity) (Meniconi et al., 2022a, 2022b) as well as the presence of elements such as dead ends (Meniconi et al., 2018, 2021) and on diameter and material of pipes (Ellis, 2008; Karney & McInnis, 1990; Starczewska et al., 2014). Thus, each WDN is characterized by a different transient response in the face of a forcing factor.…”

“…Recently, there has been evidence that users' activity (Marsili et al, 2021), that is, the opening and closing of domestic devices, can also result in the generation of pressure waves of small entity but occurring almost continuously over the day, producing deterioration that tends to worsen over time and increase failure rate (Rezaei et al, 2015). Some studies have shown that the response of the WDN to these forcing factors depends on its characteristics and, in particular, on the topological structure (i.e., network connectivity) (Meniconi et al, 2022a(Meniconi et al, , 2022b as well as the presence of elements such as dead ends (Meniconi et al, 2018(Meniconi et al, , 2021 and on diameter and material of pipes (Ellis, 2008;Karney & McInnis, 1990;Starczewska et al, 2014). Thus, each WDN is characterized by a different transient response in the face of a forcing factor.…”