Video: Is a SIL certificate alone enough to ensure a safe valve?
Ville Kähkönen (Business Manager, Oil & Gas) is interviewed during Valve World 2014 Expo (Dec 2 - 4, 2014) on the topic of his Conference paper, 'Final element safety integrity and failure data'.
Excerpt from the paper abstract: 'There is an extensive ongoing debate about failure rates such as “fail safe detected” and “fail dangerous detected” for valves and final elements used in safety instrumented systems (SIS). It seems that the failure rate data varies greatly depending on the source of data. What is actually the correct value for a certain valve type?
The difference in safety calculations, such as probability of failure on demand (PFD) and safe failure fraction (SFF), can be significant when different sources of data are used. The use of values that are significantly better than other values can lead to major cost savings due to reduced redundancy of the final elements. But can this endanger the needed risk reduction and lead to a situation where the target safety integrity level is not achieved or the tolerable risk level is exceeded?' http://metso.com
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