Rotork’s new EH electro-hydraulic range of heavy-duty valve actuators (EH) has proved to be a success in water and waste treatment plants. A recent upgrade project at the Hap Cremean water treatment plant, serving the City of Columbus in Ohio, USA, is a good example. Here, the installation of EH actuators has prevented the re-occurrence of a potentially serious contamination problem caused by hydraulic oil spillage. The EH is a stand-alone design comprising a fully enclosed power unit containing an electric motor, hydraulic pump and reservoir. Combining hydraulic positioning with electrical operation, the EH also provides the simplified remote control and indication associated with electrical actuators. A specific feature of the integral controls is the ability to adjust the speed of valve travel to precisely meet important operating criteria (for example, maximum speed without inducing water-hammer).
