PROCESS SECTION DATE NODE 100
NO PARAMETER Guide Words Deviation posssible causes possible consequences
Safe Guard/Prote ction
Action required/Recommendation
1 PRESSURE MORE - MORE - PRESSUREcontinously high flame
to the furnace.
Piping/tube thermal shock and craking lead to leakage of the heating oil to the furnace and get contact with the flame and resulting to high temperature in furnace cause cracking and Explosion
PIC 1, PT-1, PI-4, PI-5
High Alarm, High-high Alarm, fuel gas valve
malfuction - more fuel gas into the furnace
More fuel gas in the furnace, lead to high temperature in normal operation and may cause explosion during start-up.
PI 3, PI 6 & FI 3
Fuel gas control valve - fail close Interlock shut off valve Pressure Safety Valve to flare Explosion at furnace stack or Fuel gas release to
atmosphere in normal operation
PI 3, PI 6, FI 3 & AT-1
Fuel gas control valve - fail close Interlock shut off valve Pressure Safety Valve to flare Flue gas control valve,
PIC 1 malfaction - close position
High temperature of hot oil to reboiler, Distillation column experience high pressure that possible to crack and explosion.
- Pressure Safety Valve to flare Air supply to the
furnace high flow & pressure
FT 2 & PI 2 Flow Recordable Control Alarm (FRCA) link to fuel control sytem
2 PRESSURE LESS - LESS - PRESSURE
Less combustion (May caused by either less air pressure or less fuel gas)
The oil has not been heating up. The reboiler not reboil the HC, the distillation flooding, liquid HC over flow to the upper stream of distillation column.
PIC 1, PT-1, PI-4, PI-5 Pressure Low Alarm Less air pressure to
furnace for combustion
More fuel gas in the furnace, lead to explosion especially during start-up or fuel gas release to atmosphere through stack due to low combustion
FT 2 & PI 2 Additional one parallel air compressor by automatic cut in. Less fuel gas to the
furnace
The oil has not been heating up. The reboiler not reboil the HC, the distillation flooding, liquid HC over flow to the upper stream of distillation column.
FI 3, PI 3 & PI 6 and bypass valve
Flow Low alarm 3 TEMPERATURE MORE - MORE -
TEMPERATURE
High flame in the furnace (high fuel and air)
Piping/tube crack or burst due to overheating, mixture of oil burn and cause black smoke release TI 8
Automatic shut down heater on low air flow and/or low air/fuel ratio. High coke in furnace and piping, less heat transfer TI 8 Maintenance (cleaning) less hot oil flow to the
tubing (less heat transfer )
Thermal craking to the furnace - fuel gas release can cause
a jet fire FT 1 BCPS link to FT 1 and Low flow alarm
TEMPERATURE LESS - LESS - TEMPERATURE
No ignition and No flame in the furnace
High Fuel gas in the furnace - when it ignited it will exploded during start-up pilot light
Temperature alarm low, additional one pilot light , automatic cut off the fuel and air supply
No heat transfer to Hot oil - No heating to reboiler of the distalltion column, if the Feed of the distillation is liquid, the distillation will flooding
pilot light
Temperature alarm low, additional one pilot light , automatic cut off the fuel and air supply
No air Flow High Fuel gas in the furnace - when it ignited it will exploded FT 2, PI 2
Air Flow Alarm Low and automatic shut down the fuel supply on low air flow and/or low air/fuel ratio. No fuel flow
No heat transfer to Hot oil - No heating to reboiler of the distalltion column, if the Feed of the distillation is liquid, the distillation will flooding
FI 3
Fuel Flow Alarm Low and automatic shut down the air supply on low air flow and/or low air/fuel ratio.
COMPOSITION NOT CORRECT - NOT CORRECT - COMPOSITION
not corret stoikometri for perfect combustion of fuel gas
High black smoke release to Atmosphere. - Automatic shut down the heater on low air flow and/or low air/fuel ratio. Less heat transfer to the hot oil tubing/piping, less
separation in distillation column, can lead to tower flooding,
4 OTHERS
VALVE
fuel gas valve malfuction - cause leakage to furnace. un-adequate maintenance of valve and instrument
explosion when fuel gas over filling in the furnace with out combustion, and operator tried to start up the plant.
PILOT LIGHT no pilot light
un-adequate maintenance of valve and instrument
explosion when main firing started. Periodic Maintenance explosion when the enough pressure of fuel gas in the
furnace MAINTENANCE un adequate maintenance of Piping and instrumentation
Budget Control and un-aware of the risk
Instrument malfunction - lead to false reading and indication and can lead to Explosion. Piping will crack Furnace will crack
SHUT DOWN & START UP
Not follow Procedure Human Factor
Explosion can happen if not following the SU and SD procedure.
HAZOP STUDY
Furnace/burner used to heat up using fuel oil + air Heating oil to 250 C to supply to Distillation re boiler
PROCESS Section
Date
NODE
200
NO PARAMETER Guide Words Deviation
FLOW
MORE - MORE - FLOW
LESS - LESS - FLOW
NO - NO - FLOW
OTHERS THAN
VALVE Valve malfuction
MAINTENANCE SHUT DOWN &
START UP Not follow Procedure
HAZOP STUDY
Air line supply to the furnace
posssible causes possible consequences Safe Guard/Protection
the valve or control valve malfuction air to fuel ratio not as per
stoikiometric, FT 2
high presure in the
furnace PT 1, PI 4 & PI 5
more gas rushing out to
atm, PIC 1
piping leaking
air to fuel ratio not as per stoikiometric, more fuel coming out from the stack can cause
detonation/explosion
FT 2 & PI 2
piping leaking
pump/compressor failure
Piping blockage/valve malfuction
un-edequate maintenance air supply to actuator block controller malfuction cost cutting
equipment malfuction and error can occurred may lead to explosion Human Factor
Explosion can happen if not following the SU and SD procedure.
HAZOP STUDY
Air line supply to the furnace
Furnace/burner used to heat up using fuel oil + air Heating oil to 250 C to supply to Distillation re boiler
more fuel gas in the furnace can cause explosion
more flow or no flow of air to furnace
action required/Recommendation
Air Flow Alarm Low and automatic shut down the fuel supply or heater on low air flow and/or low air/fuel ratio.
Periodic Piping inspection, Risk based inspection (RBI)
Furnace/burner used to heat up using fuel oil + air Heating oil to 250 C to supply to Distillation re boiler
Air Flow Alarm Low and automatic shut down the fuel supply or heater on
PROCESS section
date
study node
300
NO PARAMETER Guide Words Deviation
1 PRESSURE MORE - MORE - PRESSURE
LESS - LESS - PRESSURE
NO - NO -PRESSURE
3 TEMPERATURE MORE - MORE - TEMPERATURE
4 FLOW REVERSE - REVERSE - FLOW
MORE - MORE - FLOW
LESS - LESS - FLOW
NO - NO - FLOW
OTHERS THAN
VALVE Valve malfuction
MAINTENANCE SHUT DOWN &
START UP Not follow Procedure
HAZOP STUDY
Fuel gas line supply to Furnace
posssible causes possible consequences
Safe
Guard/Protectio n
Fuel gas control valve malfunction
more fuel in the furnace, can cause explosion during start-up
PI 3 & PI 6
piping leaking valve malfuction valve malfuction piping leaking
external heating cause the
gas expanded explosion when enter furnace. TI 11
Fuel gas control valve malfunction - fully open
more fuel in the furnace, can cause explosion
FI 3
piping leaking valve malfuction
un-edequate maintenance air supply to actuator block controller malfuction
cost cutting equipment malfuction and error can
occurred may lead to explosion
Human Factor Explosion can happen if not following the
SU and SD procedure.
more flow or no flow to furnace
PI 3 & PI 6
FI 3
HAZOP STUDY
Fuel gas line supply to Furnace
Furnace/burner used to heat up using fuel oil + air Heating oil to 250 C to supply to Distillation re boiler
more air in the furnace, no enough heat to heat up hot oil to desired
temperature.
more air in the furnace, no enough heat to heat up hot oil to desired
Action required/Recommendation
Fuel Pressure Alarm High and automatic shut down the fuel supply or heater on low air low air/fuel ratio or high fuel supply
Automatic shut down fuel gas supply and heater
Fuel control valve - Fail close Fuel Flow Alarm High and automatic shut down the fuel supply or heater on low air
low air/fuel ratio or high fuel supply Fuel Perssure Alarm Low and automatic shut
down heater if Alarm Low Low triggered.
Fuel Flow Alarm Low
Furnace/burner used to heat up using fuel oil + air Heating oil to 250 C to supply to Distillation re boiler
PROCESS section date
study node
400
NO PARAMETER Guide Words Deviation
1
PRESSURE MORE - MORE - PRESSURE
LESS - LESS - PRESSURE
NO - NO -PRESSURE
2
TEMPERATURE MORE - MORE - TEMPERATURE
3
LESS - LESS - TEMPERATURE
4
UN-EVEN TEMP
5
COMPOSITION OTHERS THEN - OTHERS THEN - COMPOSITION
Furnace/burner used to heat up using fuel oil + air Heating oil to 250 C to supply to Distillation re boiler
HAZOP STUDY
FLOW LESS - LESS - FLOW
NO - NO - FLOW
OTHERS THAN
VALVE Valve malfuction
MAINTENANCE
posssible causes possible consequences Safe Guard/Protection
HC from reboiler leaking into heating oil tube
Possible fie inside the tube and lead to explosion of tube and burst heating oil burn in furnace - black smoke ,
less heating oil to reboiler - column flooding with HC
high combustion in furnace - more fuel and air
distillation column high pressure and
can cause explosion. TI 1 ~ TI 10 (exclude TI 8)
Low combustion in furnace column flooding with liquid HC TI 1 ~ TI 10 (exclude TI 8)
coking in the tubing piping craking and less flow to
reboiler TI 1 ~ TI 10 (exclude TI 8)
HC leaking to the heating oil, Reboiler crack, or tube cracking
Possible fire inside the tube and lead to explosion of tube and burst
-Furnace/burner used to heat up using fuel oil + air Heating oil to 250 C to supply to Distillation re boiler
piping leaking - in the furnace
HAZOP STUDY
High moisture content tube hammmering
-piping leaking to furnace heating oil burn in furnace - black smoke ,
coking in tubing column flooding with liquid HC
-piping leaking FT 1
pump failure
Piping blockage/valve malfuction
un-edequate maintenance air supply to actuator block controller malfuction
cost cutting equipment malfuction and error can
occurred may lead to explosion
Human Factor Explosion can happen if not following
the SU and SD procedure.
more flow or no flow of to furnace, no heating reboiler
Action required/Recom mendation Indication of pressure at tube Indication of pressure at tube Indication of pressure at tube Temperature High Alarm and automatic shut down the heater if Temperature Alarm High High Temperature Alarm Low and automatic shut down the heater if Temperature Alarm Low Low Temperature Alarm Low and automatic shut down the heater if Temperature Alarm Low Low Indication of composition at tube
Furnace/burner used to heat up using fuel oil + air Heating oil to 250 C to supply to Distillation re boiler
HAZOP STUDY
Vaporiser instalation at heating oil prior to inlet to furnace Indication of flow at exit stream of furnace Online decoking peridically Indication of flow at exit stream of furnace Standby pump, automatically cut in if another fail to function Online decoking peridically