Rotork IQ intelligent electric valve actuators with Rotork Pakscan two-wire digital control systems are widely used throughout Spanish solar energy plants, including those at the La Dehesa and La Florida installations in the state of Badajoz. The long range bus capabilities of Rotork’s Pakscan P3 control system make it possible to operate a bus loop of up to 20km in length with no deterioration in communication performance or the need for repeaters, making it ideal for the spacious environment of a solar power plant. Rotork is now back on the plant sites for a retrofit project on their Heat Transfer Fluid (HTF) pipework. Rotork is now installing 168 actuators and four Pakscan P3 master stations for the automation of 3 inch globe valves, to introduce remote control of the HTF temperature. Rotork is supplying a linear version of the IQTF multi-turn actuator, which operates at a relatively low output speed to provide maximum resolution and accuracy. The positional monitoring and control signal is provided by the Pakscan P3 system, using Modbus RTU protocol, over a two-wire, twisted pair bus loop. As is common with all Rotork IQPro actuators, data loggers within the IQTF units facilitate valve diagnostics by recording historical operating data and valve torque trends. The retrofit project is being carried out by Rotork Site Services.