Smart safety instrumented system
EMERSON Process Management has announced the use of automated partial-stroke testing of final control elements in its new smart safety instrumented system (SIS), an integrated solution that extends the innovations of its PlantWeb digital plant architecture to enable users to implement safer process plants and facilities.
Scheduled partial-stroking of final control elements will improve the safety level, reduce the number of risky personnel trips into the field, and increase the mandatory proof test interval.
Final control elements also employ digital intelligence with on-line diagnostics to deliver final control health information. These key options enable users to implement safer, more reliable safety systems.
The valuable options are features of Emerson's SIL3 certified Fisher(r) DVC6000 digital valve controller and SIL-PAC final control system. Together, these provide partial-stroke testing and valve diagnostics to increase reliability of Emergency Shutdown (ESD) valve solutions in safety instrumented systems .
The ESD final control system components are integrated with safety-certified sensors and SIL3 rated systems in Emerson's new digital smart SIS solutions. The ESD components and innovations are the same as those used in PlantWeb digital plant architecture for mainstream Basic Process Control System automation.
ESD valve systems are vital components of an SIS as they perform final control; they are required to take the process to a safe state when conditions dictate.
The safety-certified SIL-PAC ESD solution from Emerson is comprised of a Bettis, Hytork or El-O-Matic actuator and Fisher FIELDVUE DVC6000 digital valve controller, combined with any manufacturer's valve to provide an integrated and tested unit.
The actuators are suitable for use in Safety Integrity Level (SIL) 3 systems and the DVC6000 digital valve controller has been TÜV certified for use in SIL 1,2, and 3 applications.
With traditional safety system installations, as many as 50 percent of all faults can be attributed to the valve, which often remains static for long periods, and may not be able to operate when needed. To avoid faults, a traditional safety system uses techniques such as bypass valves and once-a-year plant shutdowns to enable full stroking of the valves to ensure they have not stuck.
These procedures are labor intensive and costly, increase risk to personnel by sending them into the field, and depend on manual actions to interrupt and then restore loops for operation.
The smart SIS solution minimises safety system valve faults by using the Fisher DVC6000 ESD device that incorporates on-line diagnostics and partial stroking to predict and identify many of the common problems that would prevent the ESD valve from operating. Use of the FIELDVUE DVC6000 digital valve controller provides flexibility to enable more frequent partial stroke testing while the plant is operational.
The smart SIS solution uses Emerson's AMS Suite: Intelligent Device Manager that provides ValveLink software to automate testing and eliminate manual intervention.
The AMS Device Manager schedules and initiates a partial stroke of the valve, and captures data on valve movement, including friction build up, air input, output and supply deviations. Alerts are generated if the valve fails to move when under test, or moves when not under test, and also if the supply pressure drops. Diagnostic testing and alerts enable users to perform predictive maintenance, anticipating and preventing problems, and improving availability of the safety systems.
By using Emerson's ESD solution, users can expect:
* * Increased safety system availability as ESD tests can be performed more frequently and problems predicted and prevented.
* * Improved personnel safety as testing can be performed remotely, minimising the need to go out into the plant.
* * Improved production availability as tests are performed while the plant is operational.
* * Reduced capital cost by eliminating bypass valves and pneumatic test panels.
* * Improved documentation as AMS Device Manager software automatically stores test data, providing a date and time stamp.
The SIL-PAC ESD solution is just one component of the smart SIS solution that includes safety-loops made by integrating Emerson's sensors, safety systems, final control elements and software. Engineered with the help of Emerson safety professionals, the safety solutions enable safer facilities, streamlined compliance, and life-cycle cost savings from engineering, through to operations and maintenance.
The Fisher FIELDVUE DVC6000 is also part of Emerson's broad range of intelligent, digital field devices that power the PlantWeb digital plant architecture to improve plant efficiency by 2% and more through delivering asset optimization, process automation, and management execution.
Further cost savings, increased plant availability, and enhanced safety and environmental compliance are achieved when the digital valve controllers are integrated into the PlantWeb architecture.
20-Aug-2004