Engineers under increasing pressure to optimise plant equipment and reduce downtime, now recognise that a traditional hard-wired arrangement of valves and field devices in a plant can no longer meet the needs of a demanding industrial environment.
The disadvantages of high costs for installation and downtime are reinforced by the fact that hardwired field devices are unable to provide detailed operational information. Digital networked systems are proving inherently more reliable and deliver advanced functionality within the network.
Tyco Valves & Controls, a world leader in valve technology, has now extended the supply chain upwards by developing a comprehensive range of intelligent digital devices capable of providing control and monitoring in networked valve systems. The flexible Tyco network solutions also have the advantage that they function with standard, open network protocols such as AS-Interface, Profibus, Foundation Fieldbus, DeviceNet and HART.
A traditional hardwire system requires a multicore signal cable running to each piece of equipment in the field. But the Tyco digital network solution requires only a single cable providing both power and communication, simplifying installation and at the same time substantially reducing the cost. In addition, the open network protocol allows the customer to more easily incorporate other equipment, including items from other manufacturers, into the same control network. The integrated fieldbus network allows the control room to command and receive detailed information from any network-connected device, including calibration data, maintenance dates, and performance information.
A single AS-Interface system can support a network including up to 62 automated valves equipped with PlantNet monitors. The protocol provides for up to 434 programmable discrete I/O ports on each network - 248 inputs and 186 outputs - and the specification includes superior diagnostics and a standard profile for analog options. The AS-Interface has a cycle time of less than 5 ms, and maximum cable length for the network is 100 metres from the PLC or master controller. This distance can be increased using network repeaters.
Network solution for Turkish LPG project
The advantages provided by Tyco's network solutions were demonstrated through the system's use on one of the most advanced LPG (liquefied petroleum gas) storage plants in the world, at Marmara-Ereglisi in northwest Turkey. Operated jointly by Totalgaz, Butangaz and Ipragaz, the facility supplies imported natural gas to a range of users including power plants.
Tyco Valves & Controls was closely involved in the engineering and pre-qualification stages of the installation, and was uniquely qualified to supply a range of ball, quarter-turn, gate, check and globe valves, many of which were fitted with Biffi ICON intelligent electric actuators.
The valve equipment was originally to be controlled by a traditional hard-wired system, requiring a multi-core signal cable linking every valve actuator. However, the Tyco project team worked alongside the plant engineers to introduce the single cable Profibus network system, delivering a substantial saving and enabling more rapid installation. The plant operators particularly appreciated their ability to interrogate actuators at any point in their life cycle, enabling engineers to make value judgements on the necessity for maintenance either on the valves or the actuators, and allowing more precise maintenance planning. For example, the Biffi ICON electric actuator stores performance information in a data log, including dates of previous five alarms and warnings, opening and closing times of the last valve stroke, motor run time, maintenance dates, serial number, and wiring diagrams.
The AVID (actuated valve interface device) range of position monitors and 'smart' positioners includes PlantNet monitors, providing a range of control possibilities from simple valve integration to complete, integrated networks. These communicate with the chosen network protocol, providing monitoring, control, calibration, commissioning and diagnostic information for the actuated valve.
These network devices have been successfully installed and implemented on many varied plants in various industries, including, oil and gas, petrochemical, chemical, food, beverage, brewing and water.
Electrically actuated valve systems are also available, and are compatible with the same open network protocols via integral, internal interfaces. The intelligence provided within the actuator allows for the same level of control and diagnostics as for pneumatic assemblies.
Finally, with the advent of FDT/DTM (field device tool/device type manager) technology, which provides intelligent asset management and integration for fieldbus devices, the utilisation of these intelligent field devices will only increase, as implementation is becoming faster, easier and more efficient.
Tyco has recognised the benefits of this technology and is a member of the FDT-JIG (Joint Interest Group) with the vision of providing certified DTMs for all of their network and intelligent field devices, thereby ensuring a single engineering tool for open engineering and asset management.
For more information contact Andy Deans, Tyco Valves & Controls Distribution SA, 011 454 4801, [email protected], www.tyco.com
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