What is a HAZOP?4. But before we can assess
risk…
we need understand
what is risk?
9. … based on the
collective knowledge of
a multi-disciplinary
team
14. Here are some examples
of process deviation…
• High Temperature
• High Pressure
• No Level
• Misdirected Flow
17. D-101 Re-boiler Condensate Pot
PSV Size ½
111 SET @ 700kPag
To atmosphere at safe
location
Steam
Drawing Ref. D-101
LT
3/4” 2” 253
3”
HLL=2550 mm
PG
253
NLL=1650 mm
LLL=250 mm LC
2”
3” 253
3/4”
6”
LY LV
253 253
Condensate
6” 6” 6”
Drawing Ref.
6”
18. What if the level
control valve fails in
the closed position?
19. D-101 Re-boiler Condensate Pot
PSV Size ½
111 SET @ 700kPag
To atmosphere at safe
location
Steam
Drawing Ref. D-101
LT
3/4” 2” 253
3”
HLL=2550 mm
PG
253
NLL=1650 mm
LLL=250 mm LC
2”
3” 253
3/4”
6”
LY LV
253 253
Condensate
6” 6” 6”
Drawing Ref.
6”
21. What if the re-boiler
condensate pot
overpressure leading to
rupture?
22. D-101 Re-boiler Condensate Pot
PSV Size ½
111 SET @ 700kPag
To atmosphere at safe
location
Steam
Drawing Ref. D-101
LT
3/4” 2” 253
3”
HLL=2550 mm
PG
253
NLL=1650 mm
LLL=250 mm LC
2”
3” 253
3/4”
6”
LY LV
253 253
Condensate
6” 6” 6”
Drawing Ref.
6”
26. D-101 Re-boiler Condensate Pot
PSV Size ½
111 SET @ 700kPag
To atmosphere at safe
location
Steam
Drawing Ref. D-101
LT
3/4” 2” 253
3”
HLL=2550 mm
PG
253
NLL=1650 mm
LLL=250 mm LC
2”
3” 253
3/4”
6”
LY LV
253 253
Condensate
6” 6” 6”
Drawing Ref.
6”
27. What is the probability
of the level control
loop failure?
29. Step 4: Evaluate the risk
based on the severity and
probability without any
safeguards
30. Lets say our scenario
have a high probability
of a control loop
failure and a high
severity due to large
production loss
35. D-101 Re-boiler Condensate Pot
PSV Size ½
111 SET @ 700kPag
To atmosphere at safe
location
Steam
Drawing Ref. D-101
LT
3/4” 2” 253
3”
HLL=2550 mm
PG
253
NLL=1650 mm
LLL=250 mm LC
2”
3” 253
3/4”
6”
LY LV
253 253
Condensate
6” 6” 6”
Drawing Ref.
6”
36. In our case the pressure
safety valve will reduce
the likelihood of a tank
rupture
37. Step 7: Make a decision to
accept the risk or make a
recommendation to
further reduce the risk
41. HAZOP alone does not
change your risks
exposure unless there
are effective actions
sustainable for
operation