4
The SIL 2 Safety Instrumented Function
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Hazard study identified a scenario where overfill of storage tanker would lead to a
Vapour Cloud Explosion
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A Buncefield type event
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Layer of Protection Analysis (LOPA) identified SIL 2 overfill protection required
©ABBGroup
October23,2016|Slide7
SIL 2 Certified Level Sensor
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Design contractor installed a
single SIL 2 Certified Radar
Level sensor to detect the high
high level and close an in-line
shut off valve
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Level sensor certified as SIL 2,
HFT 0, Type B
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Implies a single sensor can
be used for SIL 2
requirement
©ABBGroup
October23,2016|Slide8
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