State-of-the-art valve control for desalination plant

13/10/2009


State-of-the-art valve control for desalination plant

Rotork IQ and IQT intelligent electric actuators with Rotork Pakscan P3 two-wire digital control provide state-of-the-art valve control throughout the Llobregat desalination plant in Barcelona, Spain. The €230 million plant uses seawater reverse osmosis technology to supply 200,000 cubic metres/day of potable water, representing 24% of the water consumed by the 4.5 million people living in Barcelona and easing the threat of water restrictions.

More than 400 Rotork actuators have been installed, controlled by eight hot-standby Pakscan P3 master stations.  The Pakscan master stations provide a direct interface for each of the actuators controlled on its secure, two-wire loop with the Siemens Step7 PLC that operates the sequence of the recently opened plant’s processes.

The Rotork actuator and Pakscan valve control package was specified by the plant’s engineering contractor Degrement following a thorough analysis of all available actuator control bus technologies, including Profibus, Modbus and DeviceNet.  The benefit of having a fully redundant system on a single loop technology made an important contribution to the final decision.  The excellent level of support available locally from Rotork, including more than seven fully trained service engineers, was another key factor recognised by ATLL, the plant operator and the main water supply company for the city of Barcelona and the Cataluña area.

The combination of Rotork IQ actuation technology and Pakscan P3 two-wire control offers many benefits for the operator.  These include a capacity for up to 240 actuators on a single 20km, 2-wire loop, built-in diagnostic features including performance data and fault location indication, a direct reduction in cable and engineering costs and increased information flow, providing improved asset management.

Rotork IQ and IQT intelligent electric actuators embody industry-standard features for reliable and economical valve control, including non-intrusive set-up and adjustment, double-sealed IP68 watertight enclosure, data-logger and comprehensive software tools for plant records and valve diagnostics and versatility encompassing isolating, modulating and multi-port valve applications.

(Photo and text courtesy of InfoEnviro)