The contribution of UFR in measuring water volume by water meter in a single household

A test rig was set up in the Hydraulic Laboratory of the Faculty of Civil Engineering in Subotica (Republic of Serbia) to model two-outlet water supply systems (consumption was measured by water meters no. 2 and 3), with total flow rate lower than Q_n. According to the applied pressure and flow, the system models the water supply pipeline of a single household. The rated diameter of water meters is 20 mm, manufactured by Potiski vodovodi/Tisa Region Waterworks/ Ltd. Horgos (Republic of Serbia). The characteristic water meter flow rates are: flow activating the water meter propeller (Q_a) is between 0,0052 and 0,0067 m³/h, Q_min=0,05 m³/h, Q_t=0,2 m³/h and Q_n=2,5 m³/h. Upstream to water meter no. 3 a UFR was installed, manufactured by A.R.I. from Jerusalem (Israel), having a rated diameter of 20 mm, product type T30. Water supply system losses with discharges Q₃<;Q_min are modelled at water meter no. 3. Water flow at water meter no. 2 was either Q₂=0 or Q_min≤Q₂≤Q_n. According to the measurements, the most significant contribution of the UFR in measuring water volume by a water meter of a single household is in the discharge range of Q_a, just prior to activation of the water meter propeller: a) 70,47% at flow rates Q₂=0 and Q₃=0,005-0,0052 m³/h, and b) 7,47% at flow rates Q₂=0,0559-0,0577 m³/h and Q₃=0,0049-0,0050 m³/h respectively.