Boiling Liquid Expanded Vapor Explosion (BLEVE) Of Petroleum … · 2013. 1. 3. · explosion. However, if the substance involved "is" flammable, it is likely that the resulting cloud

Sudan Academy o f Sciences SAS

Boiling Liquid Expanded Vapor Explosion (BLEVE) Of

Petroleum Storage And Transportation facilities

Case Study : Khartoum State

ByEnar Gasim M otwali Elatabani

B.S.C (Hon.) Chemical Engineering

Thesis Submitted To The Sudan Academy Of Science In Partial

Fulfillment Of Requirements For Master Degree In

Cleaner Production

Supervisor:

D. K am al E ldin Eltayb Y assin

2010

Dedicated

To The

Spirit And My Parents

5

Acknowledgement

Deep thanks and gratitude to the supervisor on research

D. Kamal Eldin Eltayb , who contributed to the good

advice , assistance and support to complete this research.

Also my thanks and appreciation to the General

Administration of Civil Defense - Khartoum State - Records

Section, and thanks especially to Technical Sergeant \ Tarig

Mohammed Said who contributed to the provision of

information.

I thank all staff, teachers, Sudan Academy for Research.

p a g e II

Abstract

The objective of this study Includes the identification of possible causes

of fires and explosions resulting from Liquefied petroleum gases in

Khartoum state , methods of raising the awareness and knowledge of

risks resulting from them, in addition to the proposal of safety

precautions in the event of such incidents.

The study was conducted in highly populated Khartoum state . It was in

that context, the compilation and analysis of information on fire statistics

was carried based on data collected through field studies and records of

the civil defense - Administrative of Khartoum state ,during period

between (2007-2009).

The procedure followed include statistical analysis of the collected data

using program (e-views) method of estimation of least squares (LS). The

obtained results of this method is negative sign and the percentage of

house fires represent 98% from other types of fires (petroleum service

stations - LPG tankers).

These results, revealed that most of those fires were due to leakage of

gas in residential houses attributed to lack of awareness of possible

dangers and underestimation of safety precautions compared to those

taken in to consideration in petroleum service stations and during

transportation phases.

page III

m .. - .......^

rThe main recommendation of this study is to strengthen means of

raising public awareness of dangers caused by Liquefied petroleum

gases fire through special m edia programs and training of workers in the

field of civil defense and the empowerment of safety procedures.

p a g e IV

ف هد ن ال سة هذه م را د ل ال شم د ت حدي ب ت سبا لأ ة ا مل حت م ق ال رائ ح ت لل را جا لانف الناجمة وا

ت عن زا غا ة ال ي ول ر ة البت سال م ي ال ة ف لاي طوم و ر خ ق ال ر ط ع و ي رف ع و رفة ال مع من وال

ر ط خا م جة ال نات ها ال ه ٠ عن ف ضا لا ا ى ب ح إل را ت اقت طا حتيا ة ا م لا م ل ي ا ل ف ع حا مثل وقو

ك ث تل د وا ح ال

د ت وق ري ج سة أ را د ي ال ة ف لاي وم و ط ر خ ث ال ة حي كثاف ة ال ي ن كا م ل ة ا عالي د ال في تم وق

ك ر ذل طا لإ ع ا ل جم حلي ت وت ما و عل م ل ت عن ا ئيا صا ح ق إ ئ را ح ستنادا ال ى ا ت إل تم بيانا

ها ع ن جم ت م سا را د ل ة ا ني دا مي ل ت ا لا ج س ع و دفا ي ال مدن رة — ال دا ة ا لاي طوم و خر ال

ك ذل ي و رة ف ن الفت (. 2009 - 2007) مابي

د م وق ء ت را ج ل إ حلي لت ى ا صائ ح لا ت ا يانا ب ي لل م الت ها ت ع م جم خدا ست حا با سم- ح ه جل رنام ب

ة ق ري ر ط دي ت تق عا رب م ل ى ا ر صغ ت رقلإ ال ج وكان ل النتائ ص ح مت ها ال ن طي هذه م

ة ث ري ط ه ل ل سالب مث ق وت رائ ل ح ز منا ن ه/ه98 ال ع م وا ق أن رائ ح ى ال خري لأ ت ا رمحطا

مة خد ي ال ول ر لبت ت — ا لا ق ت نا زا غا ة ال ولي ر ة البت سال م ال

هذه ج و نتائ ت ال شف ن ك ظم أ ق مع ئ را ح ت ال ب كان سب ب ب ر س ز ت غا ي ال ل ف ز منا المكنية ال

ى يعزيى وهذا ص إل ى نق ع و ن ال ر م ط خا م ل ة ا مل حت م ل ن ا ز م غا ل ال تقلي ل ن وا احتياطات م

مة لا س ل ة ا رن ع مقا ك م خوذه تل مل ي ال ر ف عتبا لا ن ا ت م طا ح مة م خد ل ة ا رولي وخلال البت

ل ح را .الثقل م

ت صيا و ة الت سي رئي ل هذه ا سة ل را د ز هي ال زي ع ع ت م عي الو رف عا ن ال ر م ط خا م الناجمة ال

ق عن رائ ت ح زا غا ل ة ا ي ول ر لبت سالة ا ن الم ل م لا ج خ ء را ه ب لامي ع صة إ ب خا والتدري

ي مهن ن ال ي ل م ا ع ل ي ل ل ف جا ع م دفا ي ال مدن ن ال مكي ت وت ءا را ج ة إ م لا م ل ٠ا

ة

i

contents

Dedications......................................................................................... ........................... I

icfenowledgements.........................................................................................................11

English Abstract.........................................................................................................Ill

Arabic abstract...............................................................................................................V

Table of Contents.................... ..................................................................................VI

List of Figures........................... ..................................................................................... X

List of Tables................................................................................................................ XII

Abbreviations..................... .................................................................................. ..XIII

C H A P T E R O NE IN T R O D U C T IO N

1:2 General....................................................................................................................... 1

1:2 Objectives................................................................................................................. 2

C H A P T E R TW O L IT E R A T U R E R E V IE W

2.1 Risk Management Concepts.................................................................................. 4

2.1.1 Hazard.........................................................................................4

2.1.2 Risk.............................................................................................. 4

2.1.3 Explosion.........................................................................................4

2.1.3.1 Fire Explosion........................................................................................ 4

2.1.3.2 Vapor Cloud Explosion(VCE)............................................................. 5

2.1.3.3 Chemical Explosion...............................................................................6

page VI

F - --------------

2.1.3.4 Mechanical Explosions.................................................................. 7

2.2 BLEVE................................................................................................................7

2.2.1 Conditions Required for a BLEVE................................................. 8

2.2.2 BLEVE Warning Signs...........................................................................10

2.2.3 Mechanism of BLEVE.........................................................................10

2.2.4 Effects of Explosions................................................................................11

2.3 Transportation and Storage of (LPG)...................................................17

2.3.1 Properties of (LPG).................................................................................17

2.3.2 Bulk Storage..................................... ....................................................... 17

2.3.3 Storage and Transportation of Containers...........................................19

2.3.3.1 Transportation of cylinders.................................................................20

2.3.3.2 Parking Vehicles Used to Carry LP-Gas Cargo..............................23

2.3.3.3 Marine transportation..........................................................................23

2.3.3.5 Pipelines.................................................................................................. 24

2.4 Fire Fighting...........................................................................................................26

2.4.1 Fire.............................................................................................................. 26

2.4.2 Fires are Classified...................................................................................26

2.4.3 Water.......................................................................................................... 26

2.4.4 Foam...........................................................................................................28

p a g e VII

2.4.4.1 Types of foam..,,...................................................................................28

2.4.4.2 Foam Fire Extinguishers.................................................................... 29

2.4.5 Dry Chemical Powder............................................................................. 29

2.4.5.1 Types of dry powder............................................................................30

2.4.6 Carbon Dioxide Type............................................................................ 31

2.5 Precautions to be Taken at LPG Fires and Emergencies..............................34

2.5.1 Operations at a Leak With a Fire................................................ .....35

2.5.2 LP Gas Leak Without Fire....................................................................40

Chapter Three Materials & Methods3.1 The Study Area.................................................................................................. 42

3.1.1 The Location....................................................................................... 42

3.2 Methodology....................................................................................... 42

3.3 Working methods......................................................................................43

CHAPTER FOUR RESULT AND DISCUSSIONS

4.1 Results and Discussions....................................................................................... 44

4.2 Results..................................................................................................................... 44

---------------------------------------------------------------------------------------------------------------------------------------------------------- i'

p a g e VIII

4.3 Discussions........................................................................... ................................ 61

4.3.1 Home fires..............................................................................................61

4.3.2 Fires service stations petroleum and tankers (LPG)...................62

CHAPTER FIVE Conclusion& Recommendations

5.1 Conclusion........................................................................................................... 63

5.2 Recommendations............................................................................................... 64

Appendix........................... ................................................................................. .......65

References................................................................................................................... 66

p a g e IX

List of Figures

Figure (2-2) Vapor Cloud Explosion.................................................................... 6

Figure (2-3) Mechanism of BLEVE....................................................................11

Figure ( 2-4) Shrapnel Effect................................................................................. 14

T'lgure ( 2-5) Explosion tank........................................................................................16

Figure (2-6) rupture of cylinder............................................................................ 17

Figure (2-7)) rupture of tank.................................................................................17

Figure (2-8) Bulk storage tank Figure............................................................ 20

Figure (2-9) Foam fire extinguisher..................................................................... 30

Figure (2-10) Dry chemical fire extinguisher.......................................................32

Figure (2-10) Carbon Dioxide Fire Extinguishers............................................. 33

Figure ( 4-1) Fires House In 2007........................................................................... 47

Figure ( 4-2) Fires House In 2008........................................................................ 48

Figure ( 4-3) Fires House In 2009........................................................................... 49

Figure (4-4) The relationship between time and the fire house....................... 53

pageX

Figure (2 -1 ) Fire Explosion........................................................................................... 5

i

Figure (4-5) Relationship between time and fires petroleum service

stations & tankers (LPG)........................................................................................ 54

Figure (4-6) fires petroleum service stations and tankers (LPG) - 2007.55

Figure (4-7) fires petroleum service stations and tankers (LPG) - (2008)...56

Figure (4-8) fires petroleum service stations and tankers (LPG) - (2009).57

Figure (4-9) Compared the proportion of fires to three years...........................58

Figure ( 4-10) Compared between petroleum service station fires and tanker LPG..... 60*

p ag e XI

List of Tables

Table (2-1) Maximum Filling Limit by Weight of LP-Gas containers.............20

Table (2-2) Orientation of Cylinders on Vehicles.................................................22

Table (4-1) Statistics house fires in the period 2007 -2009................................. 46

Table (4-2) Statistics Petroleum service station fire & Tanker IPG in the

period 2007 -2009...................................................................................47

Table (4-3) Table(4-3) proportion of fires............................................................. 59

Table (4-4) Estimates of fire from (2010 to 2012)................................................ 60

p a g e XII

Abbreviations

BLEVE Boiling Liquid Expanding Vapor Explosion

LPG Liquefied Petroleum Gas

PLG Pressure liquefied gases

VCE vapor cloud explosion

NFPA National Fire Protection Association

ESV Emergency Shutoff Valve

SLT Superheat Lim it Temperature

DOT U. S. Department of Transportation

HAZCOM Hazard Communication

■

page X III

Chapter one Introduction

INTERUDUCTION CHAPTER!

1:1 General

Demand for L iquefied Petroleum Gas (LPG) is rising, particu larly in the residential

and commercial sectors o f developing and m ore developed countries. The use o f

cleaner liquid and gaseous fuels is expected to continue to increase as populations

grow and total dem and for energy in these regions rises roportionally .

The ( LPG ) w hich are stored as a liquid under pressure but vaporize into a gas

when the pressure is released, "LPG" they are generally com posed o f propane,

butane or some com bination thereof.

The expanded use o f (LPG), increases the potential for fires and /or leaks in

( LPG )containers. These containers include storage tanks in com m ercial

installations, tank trucks, railroad tank cars and portable storage tanks.

The (LPG) are used in dom estic or industrial heating, ho t w ater and cooking

systems, as refrigerants, at construction sites in salam anders, in torches, tar pots,

etc. They are also used on a lim ited scale as a m otor fuel. 8

LPG is particularly exposed to the risk o f serious accidents such as B LEV E

(Boiling Liquid Expanding V apor Explosion) is regarded as a m ajor risk in the

storage and transportation o f hazardous m aterials. N early all the cases reported in

the literature refer to open environm ents w hile BLEV Es in confined or congested

areas are very uncom m on.

ABLEVE has been issued decades ago, after som e catastrophic dam ages could be

caused by the pressure w aves generated due to the boiling and vaporization o f a

PLG along depressurization. The fragm ents o f the storage vessel at h igh speed m ay

be projected from explosion center at h igh speed and also cause serious dam age

accidents w ith fatalities, property, facilities and operators in industrial activities.

This is a type o f explosio that can occur w hen a vessel contain ing a pressurized

liquid is ruptured. Such explosions can be extrem ely hazardous.

A BLEVE results from the rupture o f a vessel (Fug - 6,7) containing a liquid

substantially above its atm ospheric boiling point. The substance is stored partly in

liquid form, w ith a gaseous vapor above the liquid filling the rem ainder o f the

container.

A BLEVE can occur even w ith a non-flam m able substance, som etim es one that 's

known for being extrem ely cold, like liquid n itrogen or liquid helium or other

refrigerants or cryogens, and therefore is no t usually considered a type o f chem ical

explosion. H ow ever, i f the substance involved "is" flam m able, it is likely that the

resulting cloud o f the substance w ill ignite after the B L EV E has occurred, form ing

a fireball and possib ly a fuel-air explosion, also term ed a vapor cloud explosion

(VCE). I f the m aterials are toxic, a large area w ill be contam inated.

In term of the historical perspective for BLEV E, w e find that In the late 1960 ’s and

the early 1970’s there w ere a num ber o f fires and B LEV E o f p ropane and other

liquefied petroleum gases resu lting from derailm ents o f railcars carrying propane

and other flam m able liquefied gases. These incidents involved fire fighter fatalities

and highlighted the need for safety im provem ents. A s a result, the U . S.

Department o f T ransportation (D OT) im plem ented new regulations for the tank

cars used to transport propane and other liquefied flam m able gases, and m ade them

mandatory and retroactive in 1980.

In 1973, product control requirem ents to p reven t the uncontro lled release o f (LPG)

from storage containers consisted prim arily o f m anually operated valves, back ­

flow check valves and excess-flow check valves.

On July 3, 1973 a propane incident occurred in K ingm an, A rizona involv ing a

propane fire at a propane tank car unload ing area in a propane bu lk storage plant.

The incident resulted in the death o f several firefighters and one p lan t em ployee.

A direct result o f th is incident (and others that occurred at approxim ately the same

time) was the addition o f a new fire protection requirem ent in the 1976 ed ition o f

National Fire P ro tection A ssociation ( N FPA ) 58.

In early editions o f N F PA 58, the prim ary consideration o f w ater as the m eans to

control a fire w as based on the fact that at that tim e, there w ere few reliable w ays

to stop the flow o f LP-gas after failures in the system and the need to apply w ater

quickly to storage containers being im pinged by flam es w as im portant.

Another significant change in the 1976 edition o f N F PA 58 w as the requirem ent

for including an Em ergency S hu to ff V alve (ESV ) in the transfer lines used

between stationary storage containers o f over 4 ,000 gallons capacity and cargo

tank vehicles. This revision w as intended to prevent product release from storage

containers in the event o f a vehicle pulling away w ith its hoses still connected. All

existing plants w ere required to com ply w ith th is requirem ent by the end o f 1980.

The 1980’s enjoyed a reduced num ber o f propane incidents in the U . S., and the

next major product control enhancem ent w as the rev ision to introduce an optional

requirement for internal tank valves in containers over 2,000 gallons in the 1992

edition of N FPA 58.

1:2 Objective:-

The general objective o f this research is to raise the aw areness and hazard

communication ( H A ZC O M ) due to B LEV E and other sim ilar risk.

The specific objective o f this research is to study and propose safety precautions in

case of BLEVE and sim ilar accidents.

3

Chapter two

Literature Review

LITERATURE REVIEW CHAPTER2

2.1 Risk Management Concepts:-

Risk M anagem ent is the Identification, A nalysis and Econom ic Control o f those

RISKS w hich can Threaten the A ssets (Property, H um an, R e p u ta tio n ) .

2.1.1 Hazard

A hazard is a rare or extrem e event in the natural or hum an-m ade environm ent

adversely affects hum an life, property or activity to the extent o f causing a disaster

. 2.1.2 Risk

Probability o f hazard and consequence that could result in an a c c id e n t. or it is

expected losses (lose o f life, injuries, dam age to property, and disruption o f

economic and social activities or livelihood) due to a particu lar hazard .

2.1.3 Explosion

2.1.3.1 Fire Explosion

Fire and explosions to cause a h igh toll from deaths and injuries, and the

investigator m ust be prepared to m ake special efforts w hen they occur. Since fire

and explosion injuries can lead to death hours, days, or even w eeks after the event,

every fire and explosion that involves serious injuries should be investigated in the

same way as a fire and explosion that has im m ediate fatalities.

Explosion a release o f energy, w hich causes a pressure discontinuity or b last w ave

show (Fug 2 -1 ) . The type o f explosion include vapor cloud explosion ( confined

and unconfmed),mechanical explosion ,chem ical explosion and BLEV E.

F igure( 2 -1 ) Fire Explosion

(www.schischek.com/ATEX_explosion-proof.htm)

2.1.3.2 Vapor Cloud Explosion(VCE)

A vapor cloud explosion (V CE) results from the ignition o f a cloud o f flam m able

vapor, gas, or m ist in w hich flam e speeds are high enough to produce significant

overpressure. I f the vapor involved is flam m able, it is likely that the resulting cloud

of flammable gas released into the atm osphere w ill ignite im m ediately after the

BLEVE has occurred, form ing a fireball. The com bustion occurs so rapidly that no

pressurized gases are generated, and therefore it is usually considered a gas fire,

not an explosion.

F ig u re (2 -2 ) V apor Cloud Explosion

(source from W ikipedia the free encyclopedia)

- Confined Explosions w hich describes an explosion o f flam m able vapor-air

mixture inside a closed system (e.g. vessel or building).

- Unconfined Explosions w hich relates to an explosion o f a flam m able

vapor-air m ixture in the open air. The latter term is very w idely used.

2.1.3.3 Chemical ExplosionIn chemical explosions, the generation o f high-pressure gas is the resu lt o f

exothermic reactions w here in the fundam ental chem ical nature o f the fuel is

changed. Chemical reactions o f the type involved in an explosion usually

propagate in a reaction front aw ay from the poin t o f initiation.

Chemical explosions can involve solid com bustibles or explosive m ixtures o f fuel

and oxidizer, but m ore com m on to the fire investigator w ill be the propagating

reactions involving gases, vapors, or dusts m ixed w ith air. Such com bustion

reactions are called propagation reactions because they occur progressively

through the reactant (fuel), w ith a definable flam e front separating the reacted and

un reacted fuel.

6

2.1.3.4 Mechanical ExplosionsMechanical explosions are explosions in w hich a high-pressure gas produces a

purely physical reaction. These reactions do no t involve changes in the basic

chemical nature o f the substances in the container. A purely m echanical explosion

is the rupture o f a gas storage cylinder or tank under high pressure resulting in the

release of the stored high-pressure gas, such as com pressed air, carbon dioxide, or

oxygen.

2.2 BLEVE

Definition o f B LEV E is independent o f the cause o f the container failure. For a

BLEVE to occur, the container has to be under pressure, the pressure has to exceed

the strength o f the container, and the container has to be w eakened in som e w ay

(impact, corrosion, fire). W alls goes on to discuss different types o f BLEV Es such

as containers failing from flam e im pingem ent. I f the liquefied gas is flam m able

and released because o f a BLEV E, the im portant and dangerous dim ensions o f

fireballs and ignition o f vapor clouds have to be considered. W alls w arns that the

impression that BLEV Es are solely restricted to flam m able, liquefied gases is false.

BLEVEs occur w ith m any types o f liquefied gases, flam m able and nonflam m able.

liquefied gas fails catastrophically. It does no t m atter how the container fails. It can

be by fire im pingem ent, im pact, corrosion, etc. The B LEV E is the boiling liquid

expanding vapor explosion that happens w hen the tank opens up fully." H e goes on

to say, "A BLEV E is a physical explosion o f com pressed vapor and rapidly

vaporizing liquid. U pon vessel failure the vapor space sends out a shock w ave

from the liquid flashing to vapor. I f the m aterial is flam m able, a fireball m ay

follow it. The rapid explosion can also cause projectile effects

7

David Lesak, a nationally know n hazardous m aterials author, lecturer, and course

developer, defines a B LEV E as "a pressure release from catastrophic container

failure." The resu lt o f a B LEV E is total devastation in the im m ediate area w ith

potentially large loss o f life and property.

The size o f the B LEV E is dependent on the size and w eight o f the container along

with the amount o f liquid that rem ains inside the container at the m om ent o f the

BLEVE. Generally speaking, the b igger the container, the bigger the BLEV E.

Most flam e-induced liquefied gas BLEV Es occurred w hen there w as

approximately one-half to three-fourths o f the liquid rem aining in the container.

Essentially, the destruction o f the container produces rockets that can be propelled

great distances as a result o f the rem aining liqu id ’s vaporiz ing. A ccording to the

NFPA, deaths from these projectiles have occurred as far as 800 feet from the

BLEVE.

Additionally, the m aterial inside the container m ay no t com pletely vaporize at the

time of the BLEVE ; instead, it m ay also be propelled aw ay from the scene.

Distances for personnel from BLEV Es suggests that four tim es the fireball radius

fora specific size tank w ould be appropriate. A s an exam ple, a container o f 1,000

liters would require a safe distance o f approxim ately 100 m eters. A m inim um

distance o f 100 m eters for any size container im pinged by fire is suggested.

2.2.1 Conditions Required for a BLEVEThere are condition that m ust be available to potential for the BLEV E.

-A liquid must be present

Vapors or glass alone cannot B LEV E , liquid need no t be flam m able and the

water can BLEV E but there w ill be no fire.

8

- The liquid must be in a tightly closed container

Vented container can be subject to B LEV E if ven t dam aged or inadequate for

pressure within container.

- The temperature of the confined liquid must be above its boiling point at

atmospheric pressure

The higher the pressure at the surface o f the liquid, the h igher the

temperature required to produce boiling. W hen a container o f liquid is tightly

closed and then heated, the vapor pressure increases. The increased vapor pressure

is accompanied by an elevated boiling point. A fire is the m ost com m on

occurrence that w ill bring the tem perature above the norm al bo iling point. H eat is

not always essential. Some liquids have extrem ely low boiling points at

atmospheric pressure. These liquids are already considerably above their boiling

point, even at norm al atm ospheric pressure.

-There must be structural failure of the container

Failure may be due to:

Direct flam e im pingem ent to represent m ost com m on cause o f failure.

Container failure alm ost always occurs in the m etal around the

vapor space. M etal in contact w ith the liquid is quite d ifficu lt to heat to

the danger po in t because liquids are usually excellent conductors and

absorbers o f heat w hereas vapors are not. C ontainer failure due to m etal

fatigue, inadequate or dam age re lie f valve and m echanical dam age by

collision or corrosion.

9

2.2.2 BLEVE Warning SignsThere are several w arning occur container before the explosion such as the

pinging sound from m etal shell, d iscoloration o f container (norm ally cherry red),

flaking o f sm all m etal pieces, bubble or bulge on container, the steam from tank

Surface, shrill sound from pressure re lie f valve (especially i f increasing w ith

passage o f tim e) and the tear in tank surface .

2.2.3 Mechanism of BLEVE

BLEVE m echanism are few and often rely on very lim ited experim ental data.

Where steps o f B L EV E can be sum m arized in the follow ing show (Fug 2 - 4 ) .

lv) Failure o f vessel. V arious causes including overload heating, external hitting

or vessel corrosion m ay lead to a failure and sudden opening o f the vessel.

(ii) Phase transition. W hen the vessel fails, an instantaneous depressurization

occurs to the pressure liquefied gas stored inside. The pressurized

liquid /vapor m ixture in itially in a saturated therm odynam ic state w ith a

temperature higher than its boiling po in t becom es superheated w hen the

original vessel pressure decreases to atm ospheric pressure in few

milliseconds.

(iii) The pressurized liquid can endure w ith being superheated w hen tem perature

inside the vessel is w ell below the superheat lim it tem perature (SLT) o f the

liquid. H ow ever, i f the tem perature is above SLT, fast bubble nucleation

will start inside and finally lead to v io lent splashing o f liquid /vapor m ixture

out o f the vessel into atm osphere.

(iv) Explosion due to depressurization and bubble nucleation. A s intense phase

transition in superheated state happens, the boiling o f the liquid follow ed

by bubble nucleation, the expanding vapor from both vaporization o f the

10

liquid and the initial vapor stored in the vessel w ill together lead to an

explosion (B LEV E).Show fug (2-5).

(v) Blast wave form ation. W ith an increase in total volum e o f the expanding vapor,

by a factor o f a hundred to over a thousand fold, a pow erful b last w ave

will form and bring dam age to facilities nearby.

(vi) Vessel rupture. D ue to the pow erful b last w ave, the vessel ruptures and its

pieces/fragments fly outw ards everyw here like rocket m issiles. Show

fag (2-6)& fug (2-7).

(vii) Fireball or dispersion o f toxic fluid. The blast w ave and the vessel fragm ents

will be the only effects o f the explosion.

Cooling water

Dump excess pressure valve

Insulation

Ground for italics to avoid a builds up o f liquid gas

F igure ( 2-3) M echanism o f BLEVE-

11

2.2.4 Effects of ExplosionsAn explosion is a gas dynam ic phenom enon that, under ideal theoretical

circumstances, w ill m anifest itse lf as an expanding spherical heat and pressure

wave front. The heat and pressure w aves produce the dam age characteristic o f

explosions. The effects o f explosions can be observed in four m ajor groups b last

pressure wave effect, shrapnel effect, therm al effect, and seism ic effect.

I) Blast Pressure Front Effect.

The explosion o f a m aterial produces a large quantity o f gases. These gases expand

at a high speed and m ove outw ard from the poin t o f origin. The gases and the

displaced air m oved by the gases produce a pressure front th a t is prim arily

responsible for the dam age and injuries associated w ith explosions.

If the BLEVE happens out in the open then the b last strength at a distance o f 4 fireball radii is about 30 -40 m bar pressure . This is enough pressure to brake window glass and m ay even be able to knock som e personnel dow n .

However if the B LEV E takes place near other objects or structures then the b last wave could cause build ing to collapse , or it could propel objects over considerable distances.

You can also have a b last w ave from the com bustion o f flam m able cloud .This

could happen i f a release o f a flam m able m aterial is allow ed to m ix w ith air and

become confined in structure. I f this is ignited is could resu lt in pow erful

explosion with severe blast. This is a very difficult th reat to quantify and it can be

far reaching i f a flam m able liquefied gas is released and it does no t ignite to form

fireball then get back - late ignition could cause severe explosion.

ii) Shrapnel Effect

When the containers, structures, or vessels that contain or restrict the b last pressure

fronts are ruptured, they are often broken into pieces that m ay be throw n over great

distances. These pieces o f debris are called shrapnel or m issiles. They can cause

great damage and personal injury, often far from the source o f the explosion. In

addition, shrapnel can often sever electric u tility lines, fuel gas or o ther flam m able

fuel lines, or storage containers, thereby adding to the size and in tensity o f post

explosion fires or causing additional explosions.

Most projectiles fall short o f 4 -6 fireball radii depending on the tank size , fill

level, liquid tem perature and position relative to the tank m ain axis. Severe rocket

type projectiles go as far as 15 fireball r a d i i .

Figure ( 2-5 ) show s projectiles data from 13 B LEV E o f 400 1 tanks . A s can be

seen projectiles w ere throw n in all direction . prim ary projectiles are actual pieces

of the tank w hereas secondary projectiles are nearby objects that w ere throw n by

energy of the B LEV E .

13

iii) Thermal Effect.

Combustion explosions release quantities o f energy that heat com bustion gases and

ambient air to high tem peratures. This energy can ignite nearby com bustib les or

can cause bum injuries to anyone nearby. These secondary fires increase the

damage and injury from the explosion and com plicate the investigation process.

Often, it is difficult to determ ine w hich occurred first, the fire or the explosion.

All chemical explosions produce great quantities o f heat. The therm al dam age

depends on the nature o f the explosive fuel as w ell as the duration o f the high

temperatures. D etonating explosions produce extrem ely h igh tem peratures o f very

limited duration, w hereas deflagration explosions produce low er tem peratures, but

for much longer periods.

Fireballs and firebrands are possib le thertnal effects o f explosions, particu larly

BLEVEs involving flam m able vapors. F ireballs are the m om entary ball o f flam e

present during or after the explosive event. H igh-intensity , short-duration therm al

radiation may be present w ith a fireball. F irebrands are ho t or burn ing fragm ents

propelled from the explosion. A ll these effects m ay serve to initiate fires aw ay

from the center o f the explosion.

iv) Seismic Effect

As the blast pressure w ave expands, and as the dam aged portions o f large

structures are knocked to the ground, significant localized seism ic or earth trem ors

can be transmitted through the ground. These seism ic effects, usually neglig ib le for

small explosions, can produce additional dam age to structures and underground

utility services, pipelines, tanks, or cables.

15

Figure ( 2-5 ) Explosion o f tank

(vAvw.youtube.com Fuel tank explosion )

16

Figure ( 2-6 )Rupture of cylinder

(PDF Gas cylinder ruptures at filling station)

F igure ( 2-7) Rupture of tank

(source from explosion science - workshop - Saint Denis La plaine - 11/2006 )

17

2.3 TRANSPORTATION AND STORAGE OF (LPG)

2.3.1 Properties of (LPG)

LP G are non-toxic and non-poisonous. They are however slightly anesthetic.

When inhaled over a long period of time, LPG w ill cause headache or nausea.

Asphyxiation can occur due to oxygen displacement and it is odorless, an

odorizing agent is added only when it is processed for domestic consumption, they

are flammable. In the liquid state, LPG present a hazard similar to a highly volatile

flammable liquid but with more rapid vaporization and they are heavier then air.

2.3.2 Bulk Storage

Storing and handling LPG at fixed storage installations where tanks are filled on

site .Design, Installation and Operation of Vessels Located above Ground. Matters

covered include storage tank location and safety distances; the storage tanks

themselves; their piping, valves and fittings; pumps; compressors and meters;

vaporizers; electrical considerations; fire protection; B u lk PlasaL z.

facility, the primary purpose of which is the storage and distribution of LP-Gas,

that receives LP-Gas by cargo tank vehicle, railroad tank car, or piping,

distributing this gas by portable container (package) delivery, by cargo tank

vehicle, or through gas piping ..Show fug (2-7).

Always store the tanks in an upright position. That's because the top of the tank is

where the pressure re lief valves (safety valves) are located. When upright, if

excessive pressure builds up, these valves w ill pop and bleed vapor off. While this

is not good, it is not as bad as the consequences of having the tanks resting on their

sides. In that position, the safety valves would bleed off raw liquid propane.

18

Certainly you should never store tanks near a water heater, furnace, or other

potential source of ignition. .

Also make sure that all valves are securely closed. Bleed valves, if not securely

closed have been known to work themselves open due to the expansion and

contraction caused by temperature changes.

Any storage area should be well ventilated, but don't put the tanks right next to a

vent for washers or dryers, as any leaking vapors could be sucked into these

machines or your home and create a potential hazard disaster. And never store

tanks under a stairway that might be needed to escape in the event of a fire.

As a general rule allow ten feet of clearance around the storage area. And if your

tanks become rusty, bent, or deformed in some other way, have them pressure

tested immediately.

All of us should be familiar with the danger of storing propane tanks in a van or

enclosed trailer. Ventilation is always a concern, so be sure to provide plenty. And

always check for any leaks before storing the basket with tanks in an enclosed area

ofyour vehicle.

19

Figure (2-8 ) Bulk storage tank

(source from propane transportation storage ,distribution & market development)

2.3.3 Storage and Transportation of ContainersContainer any vessel, including cylinders, tanks, portable tanks, and cargo tanks,

used for the transporting or storing of LP-Gases. Storage of cylinders the LP Gas

Storage of Full and Empty LPG Cylinders for various situations where LPG could

be stored. These include open-air storage, and indoor storage .

The capacity of an LP-Gas container shall be determined either by weight in

accordance with table ( 2-1 ) or by volume.

Location of cylinders in storage shall be located to minimize exposure to

excessive temperature rises, physical damage, or tampering and having individual

water capacity greater than 2.7 lb (1.1 kg) [nominal 1 lb (0.45 kg)] LP-Gas

capacity shall be positioned so that the pressure relief valve is in direct

communication with the vapor space of the cylinder, they are stored in buildings

shall not be located near exits, stairways, or in areas normally used, or intended to

be used, for the safe egress of occupants. - If empty cylinders that have been in LP-

Gas service are stored indoors, they shall be considered as fu ll cylinders for the

purposes of determining the maximum quantities of LP-Gas , they shall not be

stored on roofs.

Table ( 2 - 1 ) M axim um F illing L im it by W eight o f LP-Gas Containers

(percent o f m arked w ater capacity in pounds)

Specific Gravity at 60°F (15.6°C)

Oto 1200 U.S. gal (0 to 4.5 m3)Total Water Capacities, %

Over 1200 U.S.gal (0 to 4.5 rp3)Total Water Capacities, %

Underground Containers All Capacities,%

0.496-0.503 41 44 450.504-0.510 42 45 460.511-0.519 43 46 470.520-0.527 44 47 480.528-0.536 45 48 490.537-0.544 46 49 500.545-0.552 47 50 510.553-0.560 48 51 520.561-0.568 49 52 530.569-0.576 50 53 540.577-0.584 51 54 550.585-0.592 52 55 560.593-0.600 53 56 57

2.3.3.1 Transportation of cylinders

The cargo space of the vehicle shall be isolated from the driver’s compartment, the

engine, and its exhaust system. Open-bodied vehicles shall be considered to be in

compliance with this provision. Closed-bodied vehicles having separate cargo,

driver, and engine compartments shall also be considered to be in compliance with

this provision.

TCylinders and their appurtenances shall be determined to be leak-free before

being loaded into vehicles . Cylinders being transported by vehicles shall be

positioned in accordance with Table (2-2 ).

Cylinders shall be loaded into vehicles with flat floors or equipped with racks

for holding cylinders. Cylinders shall be fastened in position to minimize the

possibility of movement, tipping, and physical damage.

The vehicle used for carriage must be properly designed, of adequate strength,

good construction and properly maintained, thus making it suitable for its purpose.

The type of vehicle carriage of gas cylinders is

-Enclosed vehicle

Transporting LPG cylinders in enclosed vehicles poses significant additional risks.

For enclosed vehicles a person must not carry a cylinder of more than 30L (13.5

kg) in size. 9kg cylinders or larger gas cylinders can only be transported in

enclosed vehicles for the purposes of getting the cylinder refilled (or exchanged).

When you do have to transport your cylinder make sure it is stored securely in an

upright position (so it cannot fall over or become a projectile), and in a way that

avoids excess exposure to sunlight or heat.

- Open vehicle

Transportation of Portable Containers of More Than 1000 lb (454 kg) Water

Capacity shall be in accordance with the following:

- Containers and their appurtenances shall be leak-free before being loaded into

vehicles.

-Containers shall be transported in a rack or frame or on a flat surface.

22

\-Containers shall be fastened in a position to minimize the possibility of

movement, tipping, or physical damage, relative to each other or to the

supporting structure, while in transit.

Containers shall be transported with pressure relief devices in communication with

the vapor space.

Table (2-2) Orientation of Cylinders on Vehicles

Propane Capacity

of Cylinder

Open Vehicles Enclosed Spaces of

Vehicles

lb w.c. m3

<45 0.17

>45 0.17

Any position

Relief valve in

communication

<4.2 0.016

>4.2 0.016

with the vapor space

Any position

Relief valve in

communication with

the vapor space

23

233.2 Parking Vehicles Used to Carry LP-Gas Cargo

Vehicles carrying or containing LP-Gas parked outdoors shall comply with the

following:

(a) Vehicles shall not be left unattended on any street, highway, avenue, or

alley, except for necessary absences from the vehicle associated with

drivers’ normal duties, including stops for meals and rest stops during

the day or night.

(b) Vehicles shall not be parked in congested areas. Where vehicles shall

be permitted to be parked off the street in un congested areas, they

shall be at least 50 ft (15 m) from any building used for assembly,

institutional, or multiple residential occupancy. Where vehicles

carrying portable containers or cargo tank vehicles of 3500-gal (13-

m3) water capacity or less are parked on streets adjacent to the driver’s

residence in uncongested residential areas, the parking locations shall

be at least 50 ft (15 m) from a building used for assembly, institutional,

or multiple residential occupancy.

2.3.3.3 Marine transportationIt is vital that LPG installation standards are strictly adhered to. A ll reasonable

steps must be taken to avoid gas leakage to ensure the safety of marine and river

craft, their owners, hirers and users. Other factors such as the use of suitable gas

appliances for the situation, the provision of flues and vents, and the correct

location of cylinders and warning notices are also extremely important.

• General cargo, compressed gases, other than ships’ general stores for the LP-

Gas tank vessel, shall not be handled over a pier or dock within 100 ft (30.5

m) of the point of transfer connection while LP-Gas are being transferred.

24

___________________________________________________________________________________________

Ship bunkering operations shall not be permitted prior to or during cargo

transfer operations.

• The shore mooring equipment shall be designed and maintained to safely

hold the vessel to the pier or dock.

• If the terminal conducts transfers between sunset and sunrise, the pier or

dock area shall have a lighting system that illuminates the transfer

connection area, control valves, storage containers, other equipment and

walkways of communications, fire fighting, and other emergency areas.

• A ll lighting shall be located or shielded so that it is not confused with any

aids to navigation and does not interfere with navigation on the adjacent

waterway.

• Prior to the start of the transfer, warning signs be placed in the marine

transfer area, visible from the shoreline and berth areas. The warning signs

shall read as warning, dangerous cargo, no visitors, no smoking and no open

light.

• A LP-Gas detector shall be readily available for use at the berth.

23.3.5 PipelinesIt is generally the case that all crude oils, natural gas, liquefied natural gas,

liquefied petroleum gas (LPG) and petroleum products flow through pipelines at

some time in their migration from the well to a refinery or gas plant, then to a

terminal and eventually to the consumer. Aboveground, underwater and

underground pipelines, varying in size from several centimetres to a metre or more

in diameter, move vast amounts of crude oil, natural gas.

25

• Pipelines shall be located on the dock or pier so that they are not

exposed to damage from vehicular traffic or other possible cause of

physical damage. Underwater pipelines shall be located or protected so

that they are not exposed to damage from marine traffic.

• Pipelines used for liquid unloading only shall be provided with a

check valve located at the multiple adjacent to the multiple isolation

valve.

• A ll pipelines, conduits and other conductive lines on the berth, capable

of carrying an electrical charge, shall be equipped with insulating

flanges or other means to electrically isolate them from stray currents

and the rest of the terminal.

26

— - — — — —

2.4 Fire Fighting

Fire protection shall be provided for all u tility LPG. The extent of such protection

shall be determined by an evaluation based on quantity, and size of storage

Containers; an analysis of local conditions; hazards within the facility; and

exposure to and from other property.

2.4.1 Fire

The rapid oxidation of a fuel evolving heat, particulates, gases and non-ionizing

radiation. Fires need four elements in order to occur fuel, oxygen, heat and

chemical Reaction.

2.4.2 Fires are Classified

Class A:- Ordinary combustibles or fibrous material such as wood, paper, cloth,

rubber and some plastics.

Class B:- Flammable liquids such as gasoline, kerosene, oil, paint, paint

thinners and propane.

Class C:- Energized electrical equipment such as appliances, switches, panel

boxes and power tools.

2.4.3 Water

Of the great importance of water are used in the event of fire , petroleum reservoirs

and most importance of theses uses in the cooling tank to reduce the temperature as

much as possible, the protection of reservoirs adjacent to the burning tank of high

heat, processing of the foam solution and mixing it with solution center percentage

r * ~ —

27

required and washing of petroleum product falling on the ground and expel the

water in the direction of sewage to keep afire risk .

The type of water

• Plain water Is non-water mixture or processor in any other additional

material which has a Surface tension high and this Surface tension

high does not help the speed of sliding and movement of objects in

addition to double penetrate porous materials.

• Wet water is the treated water with chemicals the other to reduce

surface tension and this water has the ability to penetrate the porous

materials thus to allow for more efficient cooling

• Thick water Is the treated water with additional material the other to

reduce the flow ability and therefore this is slow movement and

remains in place to be cooled more and not have the ability to

penetrate porous materials, but it helps of sliding .

• Rapid or Slippery water Is the treated water chemically to reduce

the viscosity and thus reduces the pressure loss caused by friction loss

inside the hose reel which maintains the water pressure required and

helps to deliver water to the distant.

Water used in firefighting is either sweet or salty. Wet water is the best among all

types of water mentioned above, normal water is the most common use because

provided of large quantities.

Fire extinguishers water are intended primarily for use on Class A fires. The

stream in itia lly should be directed at the base of the flames. After extinguishment

of flames, it should be directed generally at smoldering or glowing surfaces.

28

2.4.4 Foam

Fire-fighting foam is an aggregate of air-filled bubbles formed from aqueous

solutions and is lower in density than flammable liquids. It is used principally to

form a cohesive floating blanket on flammable and combustible liquids and

prevents or extinguishes fire by excluding air and cooling the fuel. It also prevents

re-ignition by suppressing formation of flammable vapors. It has the property of

adhering to surfaces, which provides a degree of exposure protection from adjacent

fires.

Foam can be used as a fire prevention, control, or extinguishing agent for

flammable liquid hazards. Foam for these hazards can be supplied by fixed piped

systems or portable foam-generating systems.

Foam Solution. A homogeneous mixture of water and foam concentrate in the

proper proportions .The percent of foam concentrate contained in a foam solution.

The type of foam concentrate used determines the percentage of concentration

required. For example, a 3 % foam concentrate is mixed in the ratio of 97 % parts

water to 3 parts foam concentrate to make foam solution.

2.4.4.1 Types of foam

• Chemical foam which is carbonate of soda and aluminum sulfate.

• Protein-Foam or mechanical foam which is a liquid composed of residues

of proteins such as bones and hoofs . It is able to prevent corrosion of

equipment and containers, to resist bacterial decomposition and to control

viscosity. They are diluted with water to form 3 percent to 6 percent

solutions depending on the type.

29

• Fluoroprotein-Foam ( protein + fluorine) it is more effective ,resistant to

heat and pollution . They are diluted with water to form 3 percent to 6

percent solutions depending on the type.

2.4.4.2 Foam Fire Extinguishers

AFFF (aqueous film-forming foam) and FFFP (film-forming fluoroprotein)-

type fire extinguishers are rated for use on both Class A and Class B fires. They

are not suitable for use in freezing temperatures. An advantage of this type of

extinguisher when used on Class B flammable liquid fires of appreciable depth

is the ability of the agent to float on and secure the liquid surface, which helps

to prevent re-ignition . Fire extinguishers of these types are usually available in

hand portable models of 1.6 gal (6 L)’and 2 1/2 gal (9.46 L) and in wheeled

models having a liquid capacity of 33 gal (125 L).

30

C€

F igure ( 2-9) Foam w heeled extinguisher & Foam extinguisher

(www.fire-safety-equipment.co.uk/fire-extinguishers/foam-fire-extinguishers )

2.4.5 Dry Chemical Powder

This powder works to break the chain of chemical interaction and the heroes of

continuity , cooling due to chemical interaction of this powder or thermal

decomposition which it is heat absorption and decrease the temperature, asphyxia

(interaction of dry powder (BC)) and prevents thermal radiation.

There are two methods whereby a dry chemical agent can be discharged from a fire

extinguisher shell, depending on the basic design of the fire extinguisher. They are

the cartridge/cylinder-operated method and the stored-pressure method. Regardless

of fire extinguisher design, the method of agent application is basically the same.

Stored-pressure fire extinguishers are available in capacities from 1 lb to 30 lb (0.5

kg to 14 kg) for hand fire extinguishers and 125 kg to 250 lb (57 kg to 113.5 kg)

for wheeled fire extinguishers. Cartridge/cylinder-operated fire extinguishers are

Dry chemical fire extinguishers are also available in no rechargeable, no refillable

types that contain the agent and expellant gas in a single, no reusable, factory-filled

container. Most dry chemical fire extinguishers having ratings of 20-B and less

will discharge their contents in 8 seconds to 20 seconds. Fire extinguishers with

higher ratings could take as long as 30 seconds. Therefore, since there is little time

for experimentation, it is important that the operator be prepared to correctly apply

the agent at the outset. A ll dry chemical fire extinguishers can be carried and

operated simultaneously, and can be discharged intermittently. The discharge

stream has a horizontal range of 5 ft to 30 ft (1.5 m to 9.2 m), depending on fire

extinguisher size. When used on outdoor fires, maximum effectiveness can be

achieved when the direction of the wind is on the back of the operator.

31

2.4.5.1 Types of dry powder

• Multipurpose dry chemical (ABC) a mixture of Mono ammonium

phosphate with Ammonium sulphate . The ammonium sulphate is

part of the basic in extinguishing the fire. Which are help increased

speed and efficiency of the firefighting process.

• Dry chemical powder(BC) the characteristic of this type is alkaline

and include the sodium bicarbonate, potassium bicarbonate,

potassium bicarbonate urea base, bicarbonate urea base, or potassium

chloride base are intended primarily for use on Class B and Class C

fires.

F igure (2 -1 0 ) Dry chemical fire extinguisher & Dry chemical Wheeled unit fire extinguisher

(www.fire-extigusherl 01 .com/cached-similar)

2.4.6 Carbon Dioxide Type

This type of fire extinguisher is primarily intended for use on Class B and Class C

fees. On all fires, the discharge should be directed at the base of the flames. The

discharge should be applied to the burning surface even after the flames are

extinguished to allow added time for cooling and to prevent possible reflash.

Hie carbon dioxide agent extinguishes by diluting the surrounding atmosphere

with an inert gas so that oxygen levels are kept below the percentage required for

combustion. When this type of fire extinguisher is used in an unventilated space,

such as a small room, closet, or other confined area, prolonged occupancy of that

space can result in the loss of consciousness due to oxygen deficiency. Hand fire

extinguishers of this type are usually available at capacities from 21/2 lb to 20 lb

(1.1 kg to 9.1 kg). Wheeled carbon dioxide fire extinguishers are usually available

incapacities from 50 lb to 100 lb (23 kg to 45 kg).

Figure (2 -1 1 ) Wheeled Carbon Dioxide Fire Extinguishers & Carbon Dioxide Fire Extinguishers

(www.ilpi.com/safety/extinguishers.html)

2.5 Precautions to be Taken at LPG Fires and EmergenciesWhenever possible, approach the fire or leak from upwind. Keep nozzle low and

aim it upward to disperse gases or flaming vapors. Use multiple lines where

necessary.

F igure ( 1 ) D isperse the gases or flam ing vapors in form ascending

Clear all Persons out of the vapor cloud area, evacuate areas in the path of the

vapor cloud immediately. Shut off all sources of ignition at the same time. Keep in

mind that LP gas is heavier, than air.

F igure ( 2) Evacuate areas in the path o f the vapor cloud

Keep everyone, not actually engaged in operations, at least 1000 feet from the front

and rear of the tank and 500 feet from the sides.

34

Figure ( 3 ) Safety distances from the source of danger

If not present, call for police assistance to establish and maintain safety zone. If

necessary, call for additional Fire Department Units. However, keep operating

personnel to a necessary minimum.

2.5.1 Operations at a Leak With a FireDo not extinguish the fire until the leak has been stopped, except under extremely

unusual conditions.

F igure ( 4 ) Control the leak

35

If the only valve that can be used to stop the flow of gas is involved in fire or is

exposed to heat or flame, consider the possibility of using a heavy fog stream to

protect member while he shuts off the valve. Proceed slowly to prevent flashback

which may entrap the member in flames. Members involved should wear masks

and protective fire clothing.

F igure ( 5 ) U sing a heavy fog stream to protect m em ber w hile he shuts o ff the valve

Tank surfaces that are exposed to heat, either from auto exposure or fire

from another source, can be protected by supplying large quantities of water on

them. Approach the tank from the sides, applying water to all exposed surfaces as

well as piping and valves.

36

F igure ( 6) Protect o f tank by supplying large quantities o f w ater

Consult chauffeurs, operating personnel or any qualified person regarding methods

of stopping the flow of gas or any pertinent information that may assist our

operations.

Where escaping gas is on fire and the flow cannot be shut off, application of large

quantities of water on the tank and piping w ill permit controlled burning, allowing

the fire to consume the contents of the tank without the danger of tank or pipe

failure. Make certain that fire is NOT extinguished.

F igure ( 7 ) controlled burning by using large quantities o f w ater

37

Portable dry chemical extinguishers are effective on small LP gas fires. Carbon

dioxide extinguishers can also be used. They should be applied at the base of the

F igure ( 8 ) U sing fire e x tin g u is h e r s

Tank failure under fire conditions usually occurs in the vapor area of the tank when

sufficient water cannot be applied to prevent the metal from softening or

weakening to a point where metal failure occurs.

F igure ( 9) Tank failure under fire conditions

38

Before tank failure occurs, the rise in pressure within the tank w ill cause an

increase in the volume of fire, or a rise in the noise level or both. This may or may

not be accompanied by a bubble or blister forming on the tank shell. When any of

these symptoms are present, the operating forces should be withdrawn to a safe

area.

F igure ( 10) The rise in pressure w ithin the tank

Ordinarily no attempt should be made to move a tank involved in a fire. Usually

little would be gained in reducing the hazard. However if specific conditions

develop that make it desirable to move the tank, it should be moved in an upright

position. Never drag it in a manner that might further damage valves or piping.

Any attempt to turn the tank upright, to remove it to some remote location or to

facilitate product withdrawal, should be done carefully to avoid damage to valves

39

F igure (1 1 ) Portable LP gas cylinders should be rem oved to a safe location

and piping, Portable LP gas cylinders that are exposed to a serious fire should be

removed to a safe location.

2.5.2 LP Gas Leak Without FireIf escaping LP gas is not on fire, close any valve available that can stop the flow of

gas. Small lines such as copper tubing could be flattened to stop the flow. If an LP

gas vehicle is involved, consult the driver; or if storage facilities are involved,

consult plant personnel regarding possibilities of shutting off leaks.

Figure (12 ) Close valve to stop the flow F igure( 13) Lines flattened to stop the flow

40

Water spray is effective in dispersing LP gas vapor. It should be used as soon as

possible, directing the spray stream across the normal vapor path and dispersing

the vapor to a safe location. Members handling the hose should avoid entering the

vapor cloud and should keep low behind the spray so that they w ill be somewhat

protected from radiant heat if the vapor should be ignited unexpectedly.

F igure ( 14) U sing spray stream o f w ater from a safe distance

If water spray is not effective in dispersing the LP gas vapor, then heavy streams of

water should be used from a safe distance.

41

Chapter three Materials and Methods

M aterials & M ethodsCH APTER3

3.1 The Study Area

3.1.1 The Location

The study area is located in Khartoum is the capital of Sudan located in the

confluence of the White Nile, Blue N ile between longitudes 31.15-34 east and

latitudes 15-16 north. Area of about 28.165 square Kilometer .

Consisting city of Khartoum from three large cities (Khartoum - Omdurman -

Khartoum North), therefore called the capital triangle .

Selected this region as a model because it.is considered one of the largest regions

in terms of space and high population density and thus represent the majority of the

terms of the number of accidents.

3.2 Methodology

- This study is based on the statistics records of fires taken from the General

Administration of C ivil Defense - Khartoum State - Department records to

determine the extent of the damage caused by these fires and physical effects of

explosions and determine the consequences on people and structures .

■This study is also based on facts taken from interviews conducted with officers -

and non-commissioned officers within the offices of civil defense to take the

information on those fires.

■As well as reports of fires already been used to strengthen and confirm the

validity of such accidents, and know the implications of injuries and property

losses.

42

3.3 Working methods

Statements have been prepared for fires Liquefied petroleum gases through the

book of daily reports of incidents of civil defense of Khartoum State has been

monitoring such incidents during the three years (2007-2009).

These data were analyzed using the program (e-views) method of estimation of

least squares (LS).

E- view method

E-Views is a simple but flexible econometric software package that runs on both

Windows machines and Macintoshes. It is primarily designed to work with time

series data, but can also be used for cross-section and panel data. The primary

function of E-Views is to enable the user to perform time series regressions and the

associated hypothesis tests, diagnostics, and correction procedures,

least squares (LS)

This method are able to extract equations for polynomials and lines from a series

of points (aka trend line)? If so, you may find the following information

enlightening. Excel uses a method of numerical analysis called the "least squares

method".

The least squares method for multiple regression has the same concept as the least

squares method for simple linear regression. The goal is to minimize the sum of

the square of the errors of the predicted y-values from the actual y-values.

We can calculate for us the function^) = ax + b that is obtained if one would

apply the Least squares method to a given set of points.

Chapter four*

Results and Discussions

RESULT AND DISCUSSIONS

4.1 Results and Discussions

This chapter presented the fires BLEVE in the period from 2007 to 2009, which

include house fires resulting from gas leak cooking fires and fires petroleum

service stations, which occurs when the discharge of tank fuel in addition to

Vehicles vector Liquefied petroleum gases.

4.2 ResultsThe table (4-1) shows the Statistics house fires, It also the figures from (4-1) to

(4-3) the relationship between months (time) and frequency of fire accidents in

homes. Figure (4-4) shows the relationship between time and the fire in the form of

curve.

The figures(4-5) to (4-9) represent the relationship between time and the fire

petroleum service stations and tanker of (LPG) in period from 2007 to 2009 . The

figures(4-10) shows the comparison between petroleum service stations and tanker

of (LPG).

The table (4-4) shows estimates of fires for the years (2010 - 2011 - 2012) and that

compensation in the equation (x=c +By +e ).

Where X = Time Y = Fire

B&C = Coefficient

e = Coefficient error

44

-

Statistics house fires in the period 2007 -2009

Month Fire house 2007 2008 2009

Jan Leak of gas 24 18 21

Feb - 26 27 27

Mar - 36 31 35

April - 39 29 37

May - 27 37 38

Jun - 25 23 39

Jul - 20 • 21 23

Aug - 31 16 34

Sep - 27 26 12

Oct - 33 37 23

Nov - 22 23 28

Dec - 21 22 24

Table (4-1)

45

---------------------------------------------------------------------------------------

■

Statistics Petroleum service station fire & Tanker IPG in the period 2007 -2009

nth Jan Feb Mar April May Jun Jul Aug Sep Oct Nov Dec Sum

r 2007 2007 2007 2007 2007 2007 2007 2007 2007 2007 2007 2007

roleumvicedon

1 1 2

cer5

- - - “ “ - “ - - - -

ar 2008 2008 2008 2008 2008 2008 2008 2008 2008 2008 2008 2008

toleumsiceion ' ' ' ' '

iker - - - - - - - - - - - - -

p 2009 2009 2009 2009 2009 2009 2009 2009 2009 2009 2009 2009

loleumliceion

1 1

ker - - - - - 1 - - 1 - “ 2

Table (4-2)

46

Relationship between months (time) and frequency o f fire accidents inhomes(2007)

Figure (4 -1 )

47

Relationship between months (time) and frequency o f fire accidents inhomes(2008)

Figure ( 4-2)

48

Relationship between months (time) and frequency o f fire accidents inhomes(2009)

Jan Febi M ar April May JI

j Jul Au Sep Oc Nov Dec2009

Figure (4-3)

49

M M

■

Method: Least Squares

Date: 11/04/10 Time: 02:59

Sample(adjusted): 2007:02 2009:12

Included observations: 35 after adjusting endpoints

Variable Coefficient

Std. Error t-Statistic Prob.

Y -0.002761 0.000777 -3.555134 0.0012

C 3 .313785 0.016026 206 .7769 0.0000

R (-l) 0.038670 0.001180 32.^5808 0.0000

Squared 0.971278 M ean dependent var 3 .266517

Adjusted R -squared 0.969483 S.D. dependent var 0.265556

IE. of regression 0.046391 Akaike info criterion3.221625

ium squared resid 0.068867 Schwarz criterion3.088309

.og likelihood 59.37843 F-statistic 541.0601

Durbin- W atson stat 2.244799 Prob(F -statistic) 0.000000

50

< ---------------------------------------------------------------------------------------

'

Y: Time

X: Fire

1= 3.313785 + -0.002761 Y + 0.038670

Breusch-Godfrey Serial Correlation LM Test:

I F-statistic 2.470909 Probability 0.101540

Obs*R-squared 4 .950047 Probability 0.084161

Test Equation:

Dependent Variable: RESID

Method: Least Squares

! Date: 11/04/10 Time: 03:01

Presample m issing value lagged residuals set to zero.

Variable Coefficient Std. Error t-Statistic Prob.

Y -0.000221 0.000750 -0.294284 0.7706

C 0.002749 0.015386 0.178641 0.8594

R (- l) -7.66E-05 0.001133 -0.067582 0.9466

R E SID (-l) -0.211884 0.175526 -1.207136 0.2368

RESID(-2) -0.368408 0.179113 -2.056843 0.0485

-

..................................................................................... ........-

51

R-squared 0.141430

Adjusted R-squared 0.026954

S.E. of regression 0.044395

Sum squared resid 0.059127

Log likelihood 62.04695

Durbin-Watson stat 2.135564

Mean dependent var -9.36E-16

S.D. dependent var 0.045005

Akaike info criterion -3.259826

Schwarz criterion -3.037633

F-statistic 1.235454

Prob(F-statistic) 0.316951

■

The relationship between time and the fire house

X -------- Y

Figure (4-4)

53

Relationship between time and fires petroleum service stations & tankers (LPG)

fires

2009 2008 2007

Figure (4-5)

fires petroleum service stations and tankers (LPG) - (2008)

Figure (4-7)

56

fires petroleum service stations and tankers (LPG) - (2009)

Figure (4-8)

Compared the proportion of fires to three years

Figure (4-9)

Petroleum service station 0.008695652

petroleum tanker LPG 0.005797101

Home Fires 0.985507246

Table (4-3) proportion of fires

58

Table (4-4) Estimates of fire from (2010 to 2012)

2012 2011 2010 Month

3.173 3.209 3.245 Jan

3.17 3.206 3.242 Feb

3.167 3.203 3.239 Mar

3.164 3.2 3.236 April

3.161 3.197 3.233 May

3.158 3.194 3.23 Jun

3.155 3.191 3.227 Jul

3.152 3.188 3.224 Aug

3.149 3.185 3.221 Sep

3.146 3.182 3.218 Oct

3.143 3.179 3.215 Nov

3.14 3.176 3.212 Dec

2012 2011 2010

37.878 38.31 38.742 Sum

59

Compared between petroleum service station fires and tanker LPG

o

Figure (4-10)

petrolum service station petrolum tanker LPG

60

4.3 Discussions

4.3.1 Home firesWe note in the fires of the gas leak at home is higher in summer and autumn, as

shown in the figures ((4-1) to (4-3)), which indicates that there is a clear relation

between fires and the high temperature and humidity and this is clear between the

decline and height as shown in Figure (4-4).

We also find that the percentage of house fires resulting from gas leak constituted

the highest percentage among other types of fires (gas stations - oil tankers), where

the percentage form 98% as shown in Figure (4-10) and Table (4-3) and this is due

to: -

* Increasing population density, which leads to increase the number of users of

cooking gas.

* Get rid of the traditional methods of cooking (the use of coal) with the

availability of modem techniques in cooking (LPG).

* Lack of commitment with the tools of home safety.

Note when the use of data and analysis of least squares we find that the coefficient

of the fire amount is negative, which means that the relationship between time and

the fire is an inverse relationship Table (4-1) and rates of fire in the decrease with

time and perhaps this is due to the proportion of high awareness of the dangers of

this gas and this is reflected in estimates of fires for three years (210 - 2011) Table

1(4-4 ).

61

4.3.2 Fires Service stations petroleum and tankers (LPG)It is noted that the fire service stations petroleum and tankers (LPG) Small fraction

of home fires and this is clear from Figure (4-5) to (4-10).

Most of the fires, petroleum service stations produced during discharge due to

; static electricity, as well as tankers to fires .May come back the reasons for theseIfires to lack of training and lack of commitment to the implementation of safety

measures.

Chapter five

Conclusion and Recommendations

Conclusion& RecommendationsCHAPTERS

5.1 Conclusion

Fire protection is one of the most important factors that lead to reducing the

incidents because they play a major role in reducing and mitigating the risk of fire

and save lives and protect property.

This study dealt with fires Liquefied petroleum gases BLEVE and relied on

statistics from records of C ivil Defense - Khartoum state, which includes the three

provinces (Khartoum - Omdurman - Khartoum North) in respect of house fires

resulting from gas leak (cooking gas) in addition petroleum station fires and

Liquefied petroleum gas tankers. It was found that

-More than 98% of house fires resulting from gas leak to a lack of awareness and

perception and how to act in case of a gas leak. Add to that the growing

population and the resulting increase in the use of cooking gas .

- Small percentage of the fire stations and fuel tankers, which result from static

electricity or lack of training .

- Attached reports indicate the fire events of this disastrous fire .

These defects may lead to fire accidents, which shows that the commitment to the

safety requirements to ensure life and property protection .

63

5.2 RecommendationsBased on the finding and result of this research many recommendations can be

drawn from this study are:-

(1) Raise awareness of the dangers of fires BLEVE, through the media

devices in coordination with the General Directorate of C ivil Defence

which is represented in the following

- knowledge of BLEVE and warning signs which occur before the

explosion and the catastrophic damages caused by explosion the

B LE VE .

(2) Take measures of prevention and caution in dealing with gas kitchens

in homes through awareness-raising to do the following :-

- Knowledge of prevention and safety measures necessary provided

in the gas cylinder and to provide guidance before dealing with

them .

- Raising awareness of how to act in case of gas leak.

- Requiring the owner of each house of the need to provide

extinguisher and learn how to use them to be placed near the

kitchen.

(3) Enforce workers service stations petroleum to make training courses

in the fire protection equipments before start jobs.

(4) Training drivers (LPG) tanker on the application of safety procedures

and how to deal with liquid gases, and factors that lead to an

explosion

64

Appendix

AppendixThe annex to the reports of fire from the diary reports of the fire to the

General Administration of C ivil Defense - Khartoum State, describes the fire

and the reasons they occur and the losses and injuries.

• The first report and second in the regions of Khartoum and

Omdurman the contains a fire caused by gas leak in houses.

• The third report represents of fire in fuel tanker explosion in the

Khartoum area and clear the effect of rupture of the tanker.

• The fourth report in the words of a fire service station petroleum in

the area of Khartoum North caused by static electricity.

سم ن اش ب حم ر م ال حي ر ال

خ — ري لاثاء اليوم بتا عة عند ٣٢ * ٠.٧١ ١٣٠̂ الث سا حآ ٠ ال صبا ر ت ما/ رد رة و شا ن ا جدة م د الن تفيجود و ق ب م حري ا ت ود ب غ وق ر را فل جب ع ب ر شهيد شا هيم ال را س اب ن شم ر الدي ة جوا ني ع صي ر شا

ث المدر ت عا حرك حو وت ث ن حاد ح ال ش ي ا لات —: ا

ض — س ؛٧٠٧٨ أ ح رب رقم التانكر تعر سيد ر ع م شركة يني ق ل ميثا ودة ال حد م ق ال حري ر ل جا ا وانف ق ات م عمليا ما ة ل رق و ر ب شي ب ب العج

ي — طن توف ك الموا ث الحال في العجب مال ن حي ي كا ة يجر م عملي حا ن وجئته الل و د س ب اواص را م م

ه ة مع لاث ن ث خري وا ا ي نقل شف سن م هيم ابر ل ك ا حد مال ه وا ة حالت ر ق ن ن س ي ق ا هم و ت رة حال ط ي خ وف منهم ت

م — ر ت خطا ة ا لادل جنائية ا ضور ال ح ع لل وق م ث ل د حا . ال

ب — ق سب حري ر ال جا لانف ة ان ; وا عملي ت ال ة ت ريق ط حة غير ب حي د ص عق ن ا ة ا ن عملي سخي الناتجة التن ت م م عمليا حا رة الل ئ دا خلقية لل ز ال ظا رة للقن ط م لم ٣٢^٢ ق ة ت ريق ط حة ب حي ن ص ه كا غسيل علي

ر طا ي القن ن البحر ف س عملية وا م النتقي م ل ت علي من ت ز ا طا ف ل ي ا ن حت مك خرة تت لاب جة ا من الناتى ق وا ن ب زي ن البت ب م ر ش ل ا

ي — د ك أ ث الي ذل و ر حد جا ق انف حري ت و ر طا رة هذه , ة الدائ ساف ش ١٥٠ م ا م ب ري ق ت ت ط سق خل و داة غرفة رث و ن ل رفأ حديثة ابوا ة ال صيان ت ل صا ة الب ري سف ت ال حنا شا ها وال حب حمد صا ى م ن ط شا عي زك ة ن سي جن ت ال ر ه تان ي غرقت ر ف كورق ي ال شرق ي ال حة ف سا م ^١ م ت ا ط سق رة و ئ ر دا طا داخل الفق

غرفة ك ال حدئ ك وا ة ذ رف غ ت بال و ا ت وت لا صي ة التر ربائي كه لاتجة ال م والث ث ,ول حد ت ت صابا ي ا فح لاروا . ا

ت — شترك ة ا ع عرب دفا ي (٦٨٦٣) المدني ال ث ف د حا م ومعها ال ا ت ل ٦ .ا ٨ ٤ ٧ضر — ن ح كا م ث ل حاد عقيد ال رال ميد ر ال د ن الدين ب ما ع — عث دفا ة المتجي ال لاي و د ال سي ابوبكر العقيد وال

د د س م ح ت ~ا ود-ثآ ست رة م ج ف ل زالرائد أم ط ر حمد الرحيم عيد ش شير ا س — الب سم رئي طة ق ب شر لاما لازم ال م حمد العظيم عبد /وال طي مي حر غ مت لا ب طة — ال ر ب ش لاما م ال ح وت غ فت لا طة ب ر ش ب ب لاما د ال قي (٢٦ ١ ر بال

رم ك م لل ل ع ل ا الشكر ولكم ب

ق ق عقي ط و ؛ق

إمبمقهق محبمه ءهمحإج لأ؛فيق؛!و يقطة /عا و ش ء وا :ل

ي الدفاع صديوادادة ن ب ل ا

اكرظءءم ؤلايةسخة ي ن ل ؛ ا

طة الميدرمذير ة شر لاي خرطوم و الر رة مدي لإدا مامة ا ع ال دفا المدني لل

ي بمادح ب ب ا ئ ل ٢٣٠٠٦ الماصة ؟م ، ١ ٠/ ٤/ ٢٤ ا د ل ا ب ت (٤٤)و جوابا ه هابة أ كبمدة م إ ب همد ا ق بميو ب في م.د طل

م ش م م ءرئء*م يوسف بالخاج ي لآ م دار ا لا ل غ ا ز ،وعلي ٩١٢٣^٢٠٠٣ ت الدين نهر اهوص / ايل و ف ل ت ا ك ر اكربمة *

طفاءوالتانكر ٩٨٣ ، ك الخاث*ث مكان الي ٨ء٧٤ إ ح نحرف وكذل /ة اكربة اخريق اليعوئ ئءا ط ٩٩ إ

ن متي ا-زاقث ءولج الي ائؤصول ويعد م في !محاك الخرق إ ئ ا ه يطرى قام ج ٠ ٩٨ ولم ،٠̂ ت ل ف أقدر ايترين بمن م م ءال ةاخء=ل ل

ة السيطرة تمت الطلمة ت ومئ محالي اف بجعد ءل ة القوات ل رك ا ث ل ر بمدم إطفائه في ا ا ئ ي ن بماوته تم -ءءث ،ا جدي وا طلمة ال ص بال شبم

ي (أم)ءدف ك بدره طف - اريفى في ك ء ، بلدة ا(-ترولي)وءدد آ

ى ت ح -م . ٣٠ صءع يوسف يالخاج بمائر ط)مة في :

س ض . . ه سس,-ر : ا

م1 ح م ف ح م ء :ي أ كهوإ ك ا -

ص ح ش م ف ع ل ة ؟عدد ت أ ي ا خ ب جزئي حريق يترفن ي ر شتق و ط ر ن خ ري ل - ا

ل ط ج ج.إلن ا < < < : ->د ة

ؤ حئئ م [سؤدار جيه مبيون ت ا

ز بمد،ي- /ا £4)1^1 ه ع .-مدما ،ئ م م م في أ؛صجه ءاج-يوسةث- ءءدي عاقاد ر ءن ،د / اد إ—أص ض ص مح^تي حنل-زن/ ؟ ؛

م في ن ،ف ظلمة صال من الدخوي محمد الواطن وأصيب /مم ايه م في اصسجم ال ف ليمإؤيوؤ1ب سا ءوربما أ ٠ ٠ يالومحءدة المحايتي إ

ن غضءإلىمح- غوطق لآيا . جديد ا

ك م م ؛م* ۴٤^٠٧ :س

ع عربات حمددة ج محلة شرطة بمن قور;محة عرية بموءدقا مدي دفا أ ف آ ءنف ا

ط ط. ض - ; إثمأ*شث آ * م؟ال-ي إف

ب ل ما أ ك ي؛ .الرسول محل ءمحا؛ق انم؛مإ يدر / فرطه >ا ج لإ؛ .-ة د إ

مءدا :ء.; محزممون /جءص شرطة ال*قءد ل . م ؤز ;

ه م ل طة القدم ا هم / ق الخوش طه إبرا

ب ئ دم ا ق ل .;~ن .٠١ • الطئب عثمان ياسر / بشرطة ا

د م ل هم يايكر محمد / شرطة اللازم ا .،؛.؛** ؛ إبرا

لازم المح-يد س /شرطة ال ر هم ك ١* أ ٠

اترهدم الرظمن ه1 لصم

ج وتم غ ف لا م ي غ رقم يوسف الخاج شرطة ض لا ي ث ة ١ المادة نحت ٢ ٤ ^ا ءا ي إجرا م ح د هرءلة ءريف <م ص همد ممالد م ر ال

ك ح ممدير سيدا م ولاية شرطة ال و ط ر خ ل ارة الئدريد/مدير دا لإ ة ا م ا ت ل ع ا ي للدفا ذن ق ل ا

ف مل ل ز - ا م ل ن ل ا

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66

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