It is crucial to realize that SIL rating is not synonymous with higher levels of availability. Proper use of redundancy, diagnostic coverage and control algorithms allow non- SIL rated control systems to achieve similar availability levels to SIL-rated systems.
Fill out the form to download the FREE white paper “A Total Integrated Approach”.
All plant workers want to reduce the safety risk associated with turbomachinery operation while avoiding nuisance trips. The goal is to run machines in an efficient manner. In this context, safety risk refers to catastrophic events, such as turbine overspeeding, which can lead to severe injury or death, not to mention lost revenue and extensive repairs. Rigorous analysis of the failure causes and their mitigation can significantly reduce the risk of catastrophic failure. However, full compliance with the safety standard requirements, such as IEC61508, can lead to additional complexity and cost in regard to control and safety system procurement. This places a greater burden on the plant engineers for selecting a safe, reliable system, and one that actually improves process operations. Thus, it is important to clarify some of the ambiguities in the definitions and usage of safety instrumented systems (SISs) and turbomachinery control systems (TCSs) and to have a discussion about various approaches to SIS and TCS implementation.