scholarly journals Laboratory Analysis of a Piston-Actuated Pressure-Reducing Valve under Low Flow Conditions

Water ◽  
2020 ◽  
Vol 12 (4) ◽  
pp. 940 ◽  
Author(s):  
Valentina Marsili ◽  
Riccardo Zarbo ◽  
Stefano Alvisi ◽  
Marco Franchini

The effectiveness of pressure-reducing valves (PRVs) for optimal pressure management of water distribution networks (WDNs) is proven, but problems and operational limitations have been highlighted by some recent experiences. In this study, we analyse the functioning of a piston-actuated pressure-reducing valve (PA-PRV) with a mechanical pilot which is subjected to low-flow regimes, a condition that is often observed in real water distribution networks. The analyses were carried out by means of laboratory tests featuring two sets of experiments, i.e., (a) by testing the behaviour of the PRV when a pre-established initial value and subsequent variation of flow rate occurs in the system and (b) by testing the PRV against a temporal series of flow rates observed at the inlet section of a real district metered area. The first set of tests showed that the PA-PRV tends not to maintain pressure at the imposed set-point and exhibits an unstable behaviour characterised by significant pressure oscillations under some flow rate conditions. The second set of laboratory tests showed that the anomalous behaviour identified in the first set of tests can occur under ordinary operational conditions of a network.

Proceedings ◽  
2019 ◽  
Vol 48 (1) ◽  
pp. 26
Author(s):  
Riccardo Zarbo ◽  
Valentina Marsili ◽  
Stefano Alvisi ◽  
Marco Franchini

Pressure reducing valves (PRVs) effectiveness for water distribution networks’ (WDNs’) optimal pressure management is proven, but problems and operational limitations have been highlighted by some recent studies. In this work, the functioning of a piston-actuated pressure reducing valve (PA-PRV), subjected to low flow regimes, is investigated by means of a laboratory test set. The results obtained highlight that the PA-PRV tends not to respect the imposed set-point value, and can present an unstable behaviour, characterised by significant pressure oscillations under some flow-rate conditions.


Water ◽  
2016 ◽  
Vol 8 (12) ◽  
pp. 575 ◽  
Author(s):  
Christian León-Celi ◽  
Pedro Iglesias-Rey ◽  
F. Martínez-Solano ◽  
Daniel Mora-Melia

2006 ◽  
Vol 53 (4-5) ◽  
pp. 503-511 ◽  
Author(s):  
D. Misiunas ◽  
J. Vítkovský ◽  
G. Olsson ◽  
M. Lambert ◽  
A. Simpson

An algorithm for the burst detection and location in water distribution networks based on the continuous monitoring of the flow rate at the entry point of the network and the pressure at a number of points within the network is presented. The approach is designed for medium to large bursts with opening times in the order of a few minutes and is suitable for networks of relatively small size, such as district metered areas (DMAs). The burst-induced increase in the inlet flow rate is detected using the modified cumulative sum (CUSUM) change detection test. Based on parameters obtained from the CUSUM test, the burst is simulated at a number of burst candidate locations. The calculated changes in pressure at the pressure monitoring points are then compared to the measured values and the location resulting in the best fit is selected as the burst location. The EPANET steady-state hydraulic solver is utilised to simulate the flows and pressures in the network. A sensitivity-based sampling design procedure is introduced to find the optimal positions for pressure monitoring points. The proposed algorithm is tested on a case study example network and shows potential for burst detection and location in real water distribution systems.


Author(s):  
Naoki Masuda ◽  
Fanlin Meng

Water distribution networks are hydraulic infrastructures that aim to meet water demands at their various nodes. Water flows through pipes in the network create nonlinear dynamics on networks. A desirable feature of water distribution networks is high resistance to failures and other shocks to the system. Such threats would at least transiently change the flow rate in various pipes, potentially undermining the functionality of the whole water distribution system. Here we carry out a linear stability analysis for a nonlinear dynamical system representing the flow rate through pipes that are interconnected through an arbitrary pipe network with reservoirs and consumer nodes. We show that the steady state is always locally stable and develop a method to calculate the eigenvalue that corresponds to the mode that decays the most slowly towards the equilibrium, which we use as an index for resilience of the system. We show that the proposed index is positively correlated with the recovery rate of the pipe network, which was derived from a realistic and industrially popular simulator. The present analytical framework is expected to be useful for deploying tools from nonlinear dynamics and network analysis in the design, resilience management and scenario testing of water distribution networks.


Water ◽  
2020 ◽  
Vol 12 (6) ◽  
pp. 1579 ◽  
Author(s):  
Giacomo Ferrarese ◽  
Stefano Malavasi

In recent years, water utilities have made worldwide investments targeted to the implementation of an effective monitoring system and the installation of pressure-reducing valves in strategic nodes of water distribution networks. In fact, these interventions are considered fast and effective solutions to address at least two main concerns of modern water utilities: leakage reduction and energy efficiency. The present paper, on the basis of a database of working conditions of installed pressure-reducing valves, discusses the range of applicability of the GreenValve system (GVS) as an alternative solution to improving standard pressure-reducing valve capabilities. The device is able to recover energy, and it can be used to create a stand-alone monitoring node with remote control ability, optimizing the network from an energetic, functional, and hydraulic point of view.


10.29007/gvnz ◽  
2018 ◽  
Author(s):  
Armando Di Nardo ◽  
Michele Di Natale ◽  
Anna Di Mauro ◽  
Eva Martínez Díaz ◽  
Jose Antonio Blázquez Garcia ◽  
...  

The recent development and applications of social network theory in many fields of engineering (electricity, gas, transport, water, etc.) allows both the understanding of networks and to improve their management. Social network theory coupled to the availability of real time data and big data analysis techniques can change drastically the traditional approaches to manage civil networks. Recently, some authors are working to apply this novel approach, based on social network theory, on the water distribution networks using: a) graph partitioning algorithms to define optimal district meter areas both for water losses identification and for water network protection, b) innovative topological, energy and hydraulic indices to analyze performance; and c) GIS (Geographical Information System) to provide a more effective display of results and to improve network behavior in specific operational conditions. In this paper, a novel release 3.5 of SWANP software, that implements all these features, was tested on a real large water network in Alcalá de Henares, Spain.


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