Event & target likelihood

Cause & likelihood

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

Mitigated likelihood

Merging of propane stream with Natural Gas main stream, causing solidification of flow in MCHE

1E−6

Tube rupture inside the heat exchangers

I.E−1

Process design

Alarms

SIS (PLC)

1E−7

Design the pipes to hold pressure much higher than that of the process

1E−2

An alarm should be present to detect whether the composition changed of the Main stream, if so operator should stop process immediately

1E−1

Logic in PLC once a composition change detected, shuts the propane cycle and directs part of main stream to the flare

1E−3