practice antony thanos ph.d. chem. eng. antony.thanos@gmail

This Project is funded by the European Union

Project implemented by Human Dynamics Consortium

This project is funded by the European Union

Projekat finansira Evropska Unija


Projekat realizuje Human Dynamics Konzorcijum

PRACTICE

Antony ThanosPh.D. Chem. [email protected]



• Hazard Identification (line from tank to pump) HAZOP technique, examine

deviations for :

o NO FLOW, LESS FLOW

o MORE TEMPERATURE

o LOSS OF CONTAINEMENT

ΟμάδαHAZOP

V-1P-2

V-2

LILI PI

LPG Tank



• Hazard Identification (cont.), HAZOP form for use

ΟμάδαHAZOP

No

Deviation CausesConsequenc

esSafeguards

Comments, Recommendatio

ns

1 No flow

2 Less flow

3More Temperature

4Loss of Containment



• Hazard Identification (cont.), answers example

ΟμάδαHAZOP

No


esSafeguards


ns

1 No Flow

V1 or V2 closed and P1 starts

Cavitation in pump, potential pump failure, as seal failure with LPG release, in prolonged or repeated cases

No remote pump start capability (local only) and V2 very close to pumpClosed suction results in excessive noise, operator will immediately identify incident

Develop written procedure to require check of proper line-up before pump start.Installation of limit switches for V1 position with position signal to pump house.

2 Less Flow

LI very low As in No.1 Procedures require check for adequate level in tank before pump start.

Examine installation of level transmitter with level indication to pump-house, along with visual alarm, forcing pump trip in very low level.



• Hazard Identification (cont.), answers example

ΟμάδαHAZOP

No


esSafeguards


ns

3More Temperature

V1 and V2 closed in summer conditions

Thermal expansion increases pressure, potential for pipe rupture

Piping test pressure according to standards

Install Thermal Relief Valve (TRV) between V1 and V2

4Loss of Containment

Piping mechanical failure Collision of vehicle in piping

Release of LPG from tank, uncontrolled if V1 cannot close (failure close to V1) or failure upstream of V1

Manual isolation of V1

Install Fail-Safe remote operated isolation valve at valve outlet (internal if possible)Establish protection of piping routing from collisions



• Accident scenarios Define some worst-case scenarios

for LPG installation

ΟμάδαHAZOP

LILI PI

LPG Tank200 m32 in hose

2 in, gas phase

LPG Tank120 m3

to other tanks,compressor

to other tanksSupply pipelinefrom refinery

LPG RoadTanker 20

tn

6 in, liquid phase



• Accident scenarios (cont.), answers example Storage area (tanks)

o Catastrophic failure of 200 m3 tank

Movement facilities

o Catastrophic failure of road tanker

o Catastrophic failure (FBR) of 6 inch pipeline from refinery

ΟμάδαHAZOP



• Top event scenarios Initial event : Catastrophic failure

of 200 m3 LPG tank, complete top events in event tree

ΟμάδαHAZOP

PHASE IGNITION CONFINEMENT TOP EVENT

DIRECT

2-PHASE

DELAYED

NO CONFINEMENT

CONFINEMENT

NO IGNITION

DIRECT

LIQUID DELAYED NO CONFINEMENT

PHASE CONFINEMENT

NO IGNITION



• Top event scenarios (cont.), answer Initial event : Catastrophic failure

of 200 m3 LPG tank

ΟμάδαHAZOP

PHASE IGNITION CONFINEMENT TOP EVENT

DIRECT FIREBALL (BLEVE)

2-PHASE

DELAYED

NO CONFINEMENT FLASH FIRE

CONFINEMENT UVCE

NO IGNITION SAFE DISPERSION

DIRECT POOL FIRE

LIQUID DELAYED NO CONFINEMENT FLASH FIRE

PHASE CONFINEMENT UVCE

NO IGNITION SAFE DISPERSION



• Risk analysis on consequence, Domino effects Comment Domino effects from

tanker BLEVE



• Risk analysis on consequence, Domino effects (cont.), comments example on “internal” effects Domino radius includes LPGSITE tanks.

Secondary accidents expected in LPGSITE tanks, resulting, in worst-case, in more severe consequences compared to primary accident (tanker BLEVE), due to higher capacity of tanks (100 m3) than tanker capacity (appr. 40 m3)

Domino radius includes other LPGSITE areas (e.g. cylinder filling station, piping network). Not significant secondary accidents, due to less severe consequences in those areas



• Risk analysis on consequence, Domino effects (cont.), comments example on “external” effects to be made from LPGSITE Domino radius includes areas of

GASCOMP site GASCOMP must be informed in order to

take the relevant risk into account in its own risk assessments

Usually no detailed map of neighbour site is available, nor details of operation

Not detailed comments to be made from LPGSITE for accidents in GASCOMP



• Risk analysis on consequence, Domino effects (cont.), example of comments to be made from GASCOMP (owner and responsible for risk analysis) on “external” effects from LPGSITE primary accident Domino area does not include GASCOMP

tanks area, or road tanker station. No secondary accidents expected in this area (excluding fragment effects)

Domino area includes pump station GASCOMP must examine accidents in

pump station (and in piping included in domino area)



• Risk analysis on consequence, effects to people



• Risk analysis on consequence, effects to people (cont.) Tank BLEVE accident in LPG

installation located within industrial park, close to village

o Very severe effects : 1500 TDU, 3rd degree burns in more than 50% of exposed population

o Severe effects : 450 TDU, 3rd degree burns in 1% of exposed population

o Mild effects : 170 TDU, 1st degree burns at significant part of exposed population

(TDU : (kW/m2)4/3. sec, be careful with units)



• Risk analysis on consequence, effects to people (cont.) Comment on effects to population Comment on access to site Comment on effects to

transportation routes Consider emergency planning

actions



• Risk analysis on consequence, effects to people (cont.), comments example Very severe effects restricted within

industrial park. 3 neighbour sites in very sever effects zone. Sections of 2 other neighbour sites in very severe effects zone

Severe effects restricted within industrial park. A few additional sites within zone

Mild effects zone includes mainly industrial park, but approaches village limits

No vulnerable places (schools etc.) within zones examined



• Risk analysis on consequence, effects to people (cont.), comments example Access to site for emergency

personnel is established via 3 alternative routes

No main transportation routes affected, only roads within industrial park. Road to village approached only by external zone



• Risk analysis on consequence, effects to people (cont.), comments example Traffic blockage to be established

at mild zone limits, in order to avoid consequences to police personnel

Precautionary blocking traffic in wider area is beneficial for protection from potential BLEVE fragments



• Risk analysis on consequence, effects to people, (cont.), comments example BLEVE can develop within rather

limited timeframe from initial event (e.g. jet flame from nearby tank)

Limited time can be available for protection actions to be implemented by authorities

Proper training for self-protection to affected population, especially for the very severe and severe effects zone, is indispensable



• Risk analysis on consequence, effects to people, (cont.), comments example Evacuation from lethal zone is a

priority, if time is available. Absolute evacuation necessity for area within fireball limit

Enclosure to closed spaces (building internal, away from windows) can be efficient protection action for the other zones

practice antony thanos ph.d. chem. eng. antony.thanos@gmail

Documents