Certified SIL Capable for Safety
October 27th, 2009
Life-saving safety equipment is becoming increasingly important in a wider cross-section of companies. At the same time, there is a growing trend to adopt best practices for the management of safety systems. Many industrial clients now demand, in addition to fire and gas system performance approvals, that designs/upgrades be in line with the Safety Instrumented System (SIS) standards of IEC61508.
The safety requirements specification of any SIS to IEC61508 includes the target Safety Integrity Level (SIL) for defined Safety Instrumented Functions (SIF). A SIF in a fire and gas safety system could be a gas or flame detector combined with the outputs to annunciate or to initiate mitigation systems.
When a device has earned a certain Safety Integrity Level, it means the device can be used in a design at that Safety Integrity Level or below. For instance, a Certified SIL2 device may be used in a SIF with a SIL2 or SIL1 risk reduction. To attain a Certified SIL Capability rating, a full IEC61508 assessment must be completed.
Properly assessing the SIL Capability of a device is an extensive process. It includes analyzing the complete device-design process: specification methods, design methods, software design, design tools, testing methods, review techniques, management of change, and documentation. In addition, it must pass fault injection testing. Only after this assessment is performed by a third party on behalf of a safety equipment manufacturer should the manufacturer use the precise phrase “certified SIL capable” to describe its SIL rating.
The IEC61508 Certified SIL Capability rating provides simple and solid safety integrity justification. A statement of SIL conformance that is not validated by a third party does not reflect a complete SIL design and verification process, and it might miss key components.
We invite you to review this brief article from PETRO Industry News about the importance of Certified SIL Capable safety devices.
If you have any questions or comments, please contact us at rss@det-tronics.com.
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