The large Danish water utility Aarhus Vand manages eight waterworks. From one of them, drinking water is supplied to the southern part of Aarhus Municipality. At the waterworks, water is taken down from a higher zone and distributed further to another supply zone. The inlet pressure is just over 10 bar, and through a pressure reducing valve this is reduced to an outlet pressure of approximately 6.8 bar.
The pipeline from waterworks to the other supply zone is relatively long, and it is flushed once a week. While the pipeline is flushed, the flow increases significantly, resulting in a higher pressure loss and thereby a lower pressure at the consumers. Raising the control valve setpoint will increase the outlet pressure. This way, the pressure at the consumers can be raised again as an increased pressure will compensate for the pressure loss in the pipeline. A stable pressure at the consumers can thus be maintained.
The control valve is a self-acting pilot operated, hydraulic valve that utilizes the power of water to change the valve opening degree.
The valve setpoint is determined by adjusting the pilot, defining the outlet pressure. In the event of a power outage, the valve will continue to regulate pressure, and water supply to the consumers will continually be secured.
The valve setpoint is determined by adjusting the pilot, defining the outlet pressure. In the event of a power outage, the valve will continue to regulate pressure, and water supply to the consumers will continually be secured.
The control valve at Åbo waterworks is fitted with an AUMA Profox actuator, so the pilot setpoint can be adjusted remotely.
