ABSTRACT
The municipal water works must be able to measure water made and water used in order to calculate percent lost water. This chapter considers Flow rate meters. Wastewater treatment plants need a flow measurement to determine solids and BOD loading to the plant, and to the receiving stream for NPDES compliance. Both water and wastewater utilities need flow measurements to calculate chemical feed rates, hydraulic loading to treatment units, tank detention times. Orifice meters have been in use since ancient Roman times in water pipes. Venturi meters, like orifice meters, measure flow in closed conduits by recording a pressure differential across a constriction in the pipe. In water filtration facilities which operate constant rate filters, the rate of flow through the filters is regulated by a valve/venturi mechanism, the Flow Rate Controller. Manometers can be installed in venturi meters or orifices instead of the pair of pressure gages.
