Metrological performance of single-jet water meters over time

Carmen Virginia Palau,Juan Manzano,Guilherme Vieira Do Bomfim,Iban Balbastre Peralta,Benito Moreira De Azevedo

doi:10.4136/ambi-agua.2205

Abstract

To maintain quality measurement of water consumption, it is necessary to know the metrology of single-jet water meters over time. Knowing the accuracy of these instruments over time allows establishing a metrological operation period for different flow rates. This will aid water companies to optimize management and reduce economic losses due to unaccounted water consumption. This study analyzed the influence of time on the measurement error of single-jet water meters to evaluate the deterioration of the equipment and, with that, launch the metrological operation period. According to standards 8316 and 4064 of the International Organization for Standardization (ISO), 808 meters of metrological Class B were evaluated in six water supplies, with age ranges of 3.7 to 16.4 years of use. The measurement error was estimated by comparing the volume measured in a calibrated tank with the volume registered by the meters at flow rates of 30, 120, 750 and 1,500 L h-1. The metrological operation period of the meters was obtained for each flow rate by the relation between error of measurement and time of use (simple linear regression). According to the results, the majority of the equipment presents increasing under-registration errors over time, more pronounced at low flow rates and with less favorable operating conditions. The metrological operation period for flow rates of 30, 120, 750 and 1,500 L h-1 is estimated at approximately 3, 8, 14 and 13 years. This operation period combined with consumption patterns of users will establish the best time to replace the meters.

Highlights

Single-jet water meters are the most widely used velocity meters for quantifying domestic water consumption (Szilveszter et al, 2017), mainly due to their low cost and high reliability (Arregui et al, 2007)
High under-registered errors at low flow rates can be explained by increasing friction in the rotary drive, which requires a higher flow rate to begin the movement
In water supply 1, Models 'a' and 'f' show the most severe under-registration errors operating at low flow rate, in addition to the greater number of stopped and deteriorated equipment

Summary

Introduction

Single-jet water meters are the most widely used velocity meters for quantifying domestic water consumption (Szilveszter et al, 2017), mainly due to their low cost and high reliability (Arregui et al, 2007). This technology is used in residential areas (Arregui et al, 2016) and in small areas of pressurized irrigation systems (Daneshnia et al, 2015). 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)

Methods

Results

Conclusion