Accuracy of single-jet and multi-jet water meters under the influence of the filling process in intermittently operated pipe networks

Abstract

In many areas of the world water distribution systems are operated intermittently. The alternate filling and emptying of the pipe network leads to effects, which have negative impacts on water meter accuracy. For example, air that is present in the pipe network due to the emptying process must exit the network during the subsequent filling process. A part of this air is discharged through service connections and, thus, through water meters. In this paper, a study is presented in which the measurement error of single-jet and multi-jet water meters due to the filling process of an empty pipe is investigated experimentally. From the start of air flow to the steady-state flow of water, several causes of measurement errors can be distinguished, such as pure air flow, the impact of the water front on the impeller, the existence of two-phase flow or unsteady flow conditions. For both meter types, it has been discovered that the measurement error is mainly caused by the air flow. The experimental results show that up to 93% of the air volume in the pipe is registered by the water meters. Based on these results, an approach for estimating the measurement error for both meter types is presented.

Water Loss Assessment in Distribution Networks: Methods, Applications and Implications in Intermittent Supply

“…In the top-down water audit, the AL components are estimated. To determine customer meter inaccuracies, a representative sample is tested in the laboratory at different flow rates that represent the field conditions (Arregui et al 2007;Arregui et al 2006b;Walter et al 2018). Data handling and billing errors are estimated by investigating historical billing records and trends (AWWA 2016;Mutikanga et al 2011a;Vermersch et al 2016).…”

Design and Implementation of a Self-Powered Smart Water Meter

“…As shown in Figure 1, jet meters are based on the tangential incidence of a single jet (or multiple jets) over a radial-vaned impeller placed inside the meters [16]. Consequently, the angular velocity of the impeller is proportional to the circulating water flow rate.…”

Untitled

“…Over time, like any mechanical instrument, these water meters present a natural deterioration of their mobile elements that can cause significant measurement errors. The problem is more serious when this wear is accelerated by external factors, such as inadequate mounting position, reduced pressure in the network (Arregui et al, 2007), poor water quality (Buck et al, 2012), water freezing (Cichoń and Królikowska, 2016), on-site leakage (Couvelis and van Zyl, 2015), storage tanks (Mutikanga et al, 2011), partial blockage of the inlet strainer, water consumption patterns (Arregui et al, 2005), different manufacturers (Shields et al, 2012), and intermittently operated pipe networks (Walter et al, 2018).…”