Event & target likelihood | Cause & likelihood | IPL (Integrated Protection Layers) and its PFD (Process Failure on Demand) | Mitigated likelihood | ||
Liquid carried over from the top of the scrub tower by the gas causing hydrate formation
1E−5 | Fail of the sensor to read high level, or fail of the valve at bottom of the tower to open to drain liquid
1E−2 | Human action | Alarms | SIS (PLC) | 2.6E−7 |
Human response to the alarm and manually open the valve
1E−1 | A noticeable Alarm that would start if the level did not decrease after the sensor’s read within a few minutes
2.6E−1 | Logic in PLC once a change in the liquid composition detected after the scrubber with a reasonable amount, automatically MCHE would be pay passed to prevent Hydrate formation.
1E−3 |