Event & target likelihood

Cause & likelihood

IPL (Integrated Protection Layers) and its PFD (Process Failure on Demand)

Mitigated likelihood

Gas coming out from bottom opening with the liquid, this might cause hammering and damage to the pump

1E−5

Fail of the sensor to read low level, or fail of the pump at the bottom to stop draining liquids (sealing failure)

1E−1

Human action

Alarms

SIS (PLC)

2.6E−7

Human response to the alarm and manually close the valve

1E−1

A noticeable Alarm that would start if the level keeps decreasing after the sensor’s read within a few minutes

2.6E−1

Logic in PLC once a change in the Gas flow rate detected after the scrubber with a reasonable amount, the pump would be shutdown and the pipe after the pump sealed

1E−3