RISK ANALYSIS REPORT OF LPG PLANT, DURGAPUR OF BHARAT PETROLEUM CORPORATION LTD OCTOBER 2015
RISK ANALYSIS REPORT
OF
LPG PLANT, DURGAPUR
OF
BHARAT PETROLEUM CORPORATION LTD
OCTOBER 2015
INDEX
Risk Analysis For BPCL LPG Bottling Plant at Durgapur, West Bengal
INDEX
SL NO
SECTION
SUBJECT
PAGE No
1 Section – 1
Introduction 1-1 to 1-2
2 Section -2
Executive summary 2-1 to 2-8
3 Section -3
Hazard Identification 3-1 to 3-4
4 Section -4
Description & Properties 4-1 to 4-5
5 Section -5
Maximum credible Accident analysis 5-1 to 5-14
6 Section -6
Hazard of LPG Spillage/ Escape from containment
6-1 to 6-3
7 Section -7
History of Past Accident 7-1 to 7-4
8 Section -8
Consequence Analysis 8-1 to 8-34
9 Section -9
Recommendation 9-1 to 9-10
1 Anx - 1 Material Safety Data sheet of LPG Attachment 1
INTRODUCTION
Page 1
Risk Analysis for BPCL LPG Bottling Plant at Durgapur, West Bengal
SECTION – I
INTRODUCTION
1.0 INTRODUCTION
M/s Bharat Petroleum Corporation Ltd., one of the leading oil marketing
companies in Public Sector is engaged in bottling of LPG Cylinders for
domestic as well as industrial purposes. Since the demand of LPG is
growing day by day, refineries are increasing their capacities for
production of more LPG along with other Oil products.
Since LPG is highly inflammable and is stored under pressure in
substantial quantities, there is potential for damage to property and injury
in the event of release of significant quantity of LPG.
Bharat Petroleum Corporation Limited,. Vide purchase order No
4505086925 dated 08.06.2015 entrusted Sonar Bharat Environment &
Ecology Pvt. Ltd., (SBEE) to carry out a ‘Comprehensive Risk Analysis’ of
the Durgapur LPG Plant. Our team of experts had visited Durgapur LPG
Plant to collect relevant data. For the purpose of obtaining specification of
different onsite facilities, pipe lines, pump Capacity as well as off site
facilities, a detailed questionnaire was prepared. During visit of our team
members, they had collected the required information’s in the format.
Pertinent documents like lay out plan., P&I diagram, were collected from
the Plant. Our team members along with the staffs of the station had gone
round the Plant. Besides operational aspect, the team was also apprised
of the organizational set up, existing system of handling Emergency
Situation, available fire fighting system
SBEE wants to put on record the excellent co operation they had received
from the respective In charge of the station and his team during entire
course of their study. We extend our thanks especially to Mr. Nirmalya
Chakraborty and Mr. Krishno Kanto Saaha for their excellent support in
preparation of the report.
INTRODUCTION
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Risk Analysis for BPCL LPG Bottling Plant at Durgapur, West Bengal
Scope of work includes the following
Identification of vulnerable sections of the plant, which are likely to
cause damage to the plant, operating staff and the surrounding
communities due to accidental release of LPG from the LPG
Plant.
Assessment of overall damage potential of the hazardous events
in relation to Plant and environment.
Assessment of total individual risk for activities in the plant.
This is an expansion project for increasing the storage capacity by
installation of 2 nos of Mounded bullet of 300 mt each. Capacity of
existing storage of LPG Plant is 450 MT (150MT x 3) .After the
proposed enhancement of storage capacity by 600 MT. Aggregate
storage capacity of the LPG plant shall stand at 1050 MT.
EXECUTIVE SUMMARY
Page 1
Risk Analysis for BPCL LPG Bottling Plant at Durgapur, West Bengal
SECTION –II
EXECUTIVE SUMMARY
2.0 INTRODUCTION
Durgapur LPG Bottling Plant of M/s Bharat Petroleum Corporation Limited
(BPCL) is located at Rajbandh Chatty, Durgapur, West Bengal. Durgapur
Rajbandh is located 11 km away from Durgapur City & 500 mtrs from NH-
2. The land area is 25 acres.
Nearest facilities are follows
SL,NO
FACILITIES
NAME
KM
1 Railway Station Rajbandh 6 km
2 Air Port Andal 20 km
3 Bus Stand Rajbandh 3 km
4 Police Station Kanksa 4 km
5 Fire Station Durgapur 5 km
6 Hospital D.S.P Hospital Durgapur 10 km
7 National Highway HH-2 0.5 km
The plant premise is bounded by the following
North BPCL Retail Installation, Small village,
South Vacant Land
East HPCL Rajbandh IRD
West Rajbandh station
EXECUTIVE SUMMARY
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Risk Analysis for BPCL LPG Bottling Plant at Durgapur, West Bengal
2.1 PROCESS DESCRIPTION
Bulk LPG is received from Haldia Refinery. Road tankers are decanted at
Tank lorry Gantry. Four Nos. of tank Lorries can be unloaded
simultaneously. Proposed project envisages addition of two bays in the in
gantry. LPG from the tank Lorries is transferred to the storage vessels
through LPG Compressors by differential pressure method
LPG from bullets is transferred through a pipeline to filling manifolds of
carousal with the help of centrifugal pumps.
The empty LPG cylinders brought into premises by Lorries are received
and stored in the empty shed. They are fed to conveyor system after due
inspection and are carried to the filling machines in the filling shed. The
filling is cut off as soon as the weight of LPG in the cylinder reaches the
desired weight. . After filling these cylinders are counter checked for
correct weight, tested for leaks from valves and body, capped and sealed
before sending them to the filled cylinder shed. Any defective cylinder is
emptied for product LPG recovery. The filled cylinder are dispatched for
distribution .through distributors.
2.2 PLANT FACILITY
RECEIVING
Bulk petroleum LPG is received by Road tankers of 18 MT
capacity. About 8 Nos of Tankers per day supply bulk LPG to the
bottling Plant. There are 4 bays for unloading the tankers. 2 more
bays are proposed to be added for unloading.
Bulk LPG is received from Haldia Refinery by Road tankers is
decanted at Tank lorry Gantry. ,
LPG from the tank lorries is transferred to the storage vessels
through LPG Compressors by pressure differential method.
EXECUTIVE SUMMARY
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Risk Analysis for BPCL LPG Bottling Plant at Durgapur, West Bengal
STORAGE
3 Nos. Bullets having a safe filling capacity of 3 x 150 MT and 2
nos of Mounded Bullet having capacity 2 x 300 MT are proposed to
be installed. On top of the Bullet two nos. of safety relief valves are
provided, one valve is set at 13.6kg/cm2 and other is set at 14.2
kg/cm2. All bullets are provided with two independent level
indicators and high level alarm. Remote operated valves are
provided in liquid and vapour lines of each storage vessels.
Technical details of the Bullets are as under :
BULLET NOS 1.2 & 3
SL,NO ITEM TECHNICAL DETAILS
1 Bullet no. 1,2 & 3 150 MT
2 Design Pressure 16 kg/cm2 at 550C
3 Operating Pressure 14.2 kg/cm2 at 550C
4 Hydro testing Pressure 20.93 kg/cm2
5 Corrosion Allowance 1.6 mm
BULLET NOS 4 & 5 (Mounded Bullet)
SL,NO ITEM TECHNICAL DETAILS
1 Bullet no. 4&5 300 MT
2 Design Pressure 16.5 kg/cm2 at 550C
3 Operating Pressure 14.2 kg/cm2 at 550C
4 Hydro testing Pressure 21 kg/cm2
5 Corrosion Allowance 1.5 mm
FILLING OPERATION
LPG from bullet is pumped to the filling plant for bottling through 24
station carousel. The system is capable of bottling various capacity
of cylinders. The filling system can turn out 50TMT per anum on
single shift of 8 hrs. The sequence of filling operation starts with the
receipts of empty cylinders and the fallowing operation are carried
out:
EXECUTIVE SUMMARY
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Risk Analysis for BPCL LPG Bottling Plant at Durgapur, West Bengal
Visual checking for defects and tare weight
De-capping
Filling
Electronic weight checking
Correction of overfilled and under filled cylinder
Valve leak / ‘O’ ring checking
Cylinder body and bung leak checking
Capping and sealing
Loading in trucks
Empty cylinders are unloaded from Lorries and manually placed
over Telescopic chain conveyor. As they move on the conveyor, the
empty cylinder is to be checked visually for defects and markings.
Defective cylinders are to be segregated. There are provission for
storing about 76680 kg empty cylinders in the empty cylinders
storage shed.
The cylinders after de-capping are moved on to the filling machine
for filling and will be filled automatically at a rate of approximately
26 cylinders per minute. Filled cylinders automatically come out of
the carousel and continue to travel in the conveyor for weight
checking. The under / over filled cylinders are separated for weight
correction. Cylinders with correct weight are to be subjected to
valve leak check, O Ring leak and body and bung leak check as
they move on the conveyor. Cylinder found defective on the above
checks will be sent for replacement of Valve in online valve
changing machine and replacement of O Ring. Sound cylinder
move on for capping and sealing the valves. Cylinders will then be
loaded on to Lorries or will be stored in the storage shed which can
store about 5000 nos of filled cylinders.
EXECUTIVE SUMMARY
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Risk Analysis for BPCL LPG Bottling Plant at Durgapur, West Bengal
AUTOMATIC FILLING PROCESS FUNCTIONAL DESCRIPTION LPG is pumped to the carousal from which the cylinders of different
sizes are filled under pressure
The system described is intended for filling standard domestic &
LPG cylinder for industrial use, with a minimum number of
operations, with process, production and monitoring function carried
out with the help of sophisticated equipment and control system.
VAPOUR EXTRACTION
The Vapour extraction system will facilitate extraction of any
leakage of LPG from around the carousel and other leak prone
areas and discharge the same at suitable elevation above the roof
level of shed. The system will be completed with exhaust fan and
necessary ducting
EVACAUTION AND VALVE CHANGE
Cylinder found defective in valves, bung or body will be evacuated
of their contents using a vapor compressor and the evacuated LPG
will be sent back to the bullets. Leaky valves will be removed and
fitted with new valves. Cylinders that require hot work will be sent to
the authorized repair shops
PURGING FACILITY
Purging will be required in the following cases: ● New cylinder received are required to be air evacuated and
LPG purged before the same are filled.
● Repaired cylinders which have been hydro tested with water
are subject to evacuation for removal of moisture and air
before refilling.
● An online purging system has been provided.
EXECUTIVE SUMMARY
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Risk Analysis for BPCL LPG Bottling Plant at Durgapur, West Bengal
2.3 PLANT UTILITIES
Air compressor/ Receiver/ Dryer
Air compressor along with air receiver and dryer are provided to
cater to the requirement of instrument air for carousel, pneumatic
ROVs, fire protection system
Compressed air is required for the following purpose
Pneumatic actuation of different on-line instruments like ROV and control valve.
Instrument actuation in LPG filling system.
For compressed air requirement, 1 no. of 198 CFM 7.0 kg/sq cm
capacity and 2 no. 100 CFM 7.0 kg/sq cm capacity air compressors
have been installed.
ELECTRICAL SYSTEM
The total power demand of the LPG filling plant is in the region of 200
KVA. Client’s battery limit has been considered as the incoming HT supply
at 11 KV and through the two-pole structure / substation would be brought
into 11 KV transformers for further onward LT distribution. Incoming supply
is taken from the state electricity board at 11 KV
TRANSFORMER
500 KVA Air cooled transformer is installed in the plant.
STANDBY POWER SUPPLY
1X380 KVA , 1X250 KVA, 1X125 KVA & 1X7.5 KVA DG sets.
ELECTRICAL FITTINGS All electrical fitting in the sensitive area are of flameproof /
intrinsically safe type.
EXECUTIVE SUMMARY
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Risk Analysis for BPCL LPG Bottling Plant at Durgapur, West Bengal
2.4 SAFETY RELATED TYPES OF UTILITIES
Some of the general safety features for the storage & handling of LPG
provided in the complex are discussed below
DESIGN The main feature of the plant is the safe design of the equipment &
pipelines .Equipment are designed, inspected stage wise tested & certified
by statutory authorities such as CCOE (Chief Controller of Explosives) &
third party in accordance with relevant codes & standards . The main
codes & standards used in the LPG bottling plant are ASME VUl or IS-
2825 or BS-5500 or equivalent duly approved by CCOE for pressure
vessels. Materials of Construction (MOC) used are SA 516 Gr. 70. Full
radiography, stress relieving & hydro-test is carried out for the vessels &
all critical drawings /documents are certified & approved by the competent
authority. All critical LPG piping is seamless carbon steel of 300 rating with
piping designed in accordance with ASTM, ANSI & equivalent codes &
standards within built margin of safety.
Intrinsic safety is largely built in into the design itself through use of time
tested standards & codes which inherently incorporate a good margin of
safety. Apart from the equipment design & selection (only well known
reputed vendors with proven safe & trouble free track record in similar
service are selected ) there are other features related to safety in the
layout .operation , shutdown systems etc
FIRE WATER STORAGE Two Above Ground Tanks having capacity 2 X 2700 KL (5400KL).
.
FIRE WATER PUMP & JOCKEY PUMP Diesel driven 3 nos. of 616Kl/Hr. 2X10Kl/Hr
EXECUTIVE SUMMARY
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Risk Analysis for BPCL LPG Bottling Plant at Durgapur, West Bengal
LPG PUMP 2 nos. of 50 Kl/Hr.
FIRE HYDRANT SYSTEM Fire hydrants have been provided to be located as per requirements
specified in OISD-144 to cover the entire plant area and Tank Lorry
Parking area.
Double Headed Hydrants - 25 Nos
Single Headed Hydrants - 5 Nos.
Water Monitors - 16 Nos
SAFETY RELIEF SYSTEM Relief system adequately designed and provided as per OISD 144
guidelines. Two sets of safety relief valves are provided on each vessel,
each relief valve having the required design, relieving capacity. Other
routed locally but to safe location
There is a locking arrangement to prevent inadvertent closing of the
isolation valves, thus rendering the tank unprotected. Relief valves are
always kept locked in open position. Relief valves are tested once a year
and calibrated, if necessary.
HAZARD IDENTIFICATION
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Risk Analysis for BPCL LPG Bottling Plant at Durgapur, West Bengal
SECTION –III
HAZARD IDENTIFICATION
3.0 ENUMERATION & SELECTION OF INCIDENTS
Effective management of a Risk Analysis study requires enumeration &
selection of incidents or scenarios. Enumeration attempts to ensure that
no significant incidents are overlooked, selection tries to reduce the
incident outcome cases studied to a manageable number.
These incidents can be classified under either of two categories: loss of
containment of material or loss of containment of energy. Unfortunately,
there is an infinite number of ways (incidents) by which loss of
containment can occur in either category. For example, leaks of process
materials can be of any size, from a pinhole up to a severed pipeline or
ruptured vessel. An explosion can occur in either a small container or a
large container and in each case, can range from a small "puff" to a
catastrophic detonation.
A technique commonly used to generate an accident list is to identify
potential leaks & major releases from fractures of all process pipelines &
vessels. This complication should include all pipe work & vessels in direct
communication, as these may share a significant inventory that cannot be
isolated in an emergency. The data generated is as shown below.
Vessel number description & dimensions
Materials present
Vessel conditions ( phase, temperature & pressure)
Inventory & connecting pining dimensions
The goal of selection is to limit the total number of incident outcome cases
to be studied to a manageable size without introducing bias or losing
resolution through overlooking significant incidents or incident outcomes.
The purpose of incident selection is to construct an appropriate set of
HAZARD IDENTIFICATION
Sonar Bharat Environment & Ecology Pvt Ltd Page 2
Risk Analysis for BPCL LPG Bottling Plant at Durgapur, West Bengal
incidents for study from the Initial List that has been generated by the
enumeration process. An appropriate set of incidents is the minimum
number of incidents needed to satisfy the requirements of the study &
adequately represent the spectrum of incidents enumerated.
3.1 CHARACTERISING THE FAILURE
Accidental release of flammable or toxic vapours can result in severe
consequences. Delayed ignition of flammable vapours can result in blast
overpressures covering large areas. This may lead to extensive loss of life
& property. Toxic clouds may cover yet larger distances due to the lower
threshold values in relation to those in case of explosive clouds (the lower
explosive limits). In contrast, fires have localized consequences. Fires can
be put out or contained in most cases; there are few mitigating actions one
can take once a vapor cloud gets released. Major accident hazards arise,
therefore, consequent upon the release of flammable or toxic vapors or
BLEVE in case of pressurized liquefied gases.
In an LPG bottling plant such as the plant in question the main hazard
arises due to the possibility of leakage of LPG during decanting (large
number of those connections etc), storage , cylinder filling & storage &
transportation. The various operations where leakage is more likely
include during compression. To formulate a structured approach to
identification of hazards and understanding of contributory factors is
essential.
3.2 BLAST OVER PRESSURES
Blast over Pressures depends upon the reactivity class of material & the
amount of gas between two explosive limits. LPG is expected to give rise
to a vapor cloud on release.
HAZARD IDENTIFICATION
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Risk Analysis for BPCL LPG Bottling Plant at Durgapur, West Bengal
3.3 OPERATING PARAMETERS
Potential vapor release for the same materials depends significantly on
the operating conditions. Since LPG is being handled at atmospheric
temperature & in pressurized conditions, LPG releases have been
considered for release scenario based on their pressure & temperature
condition.
3.4 INVENTORY
Inventory analysis is commonly used in understanding the relative hazards
& short of release scenarios. Inventory plays an important role in regard to
the potential hazard. Larger the inventory of a vessel or a system, larger is
the quantity of potential release. A practice commonly used to generate an
accident list is to consider potential leaks & major releases from fractures
of pipelines & vessels containing sizable inventories. The potential vapor
release (source strength) depends upon the quantity of liquid release, the
properties of the materials & the operating conditions (pressure,
temperature)
3.5 LOSS OF CONTAINMENT
Plant inventory can get discharged to Environment due to loss of
containment. Various causes & modes for such an eventuality have been
described. Certain features of materials to be handled at the plant need to
the clearly understood to .Firstly list out all significant release cases & then
to short release scenarios for a detailed examination.
Liquid release can be either instantaneous or continuous. Failure of a
vessel to an instantaneous outflow assumes the sudden appearance of
such major crack that practically all of the contents above the crack shall
release in a very short time. The more likely event is the case of liquid
release from a hole in a pipe connected to the vessel. The flow rate will
depend on the size of the hole as well as on the pressure in front of the
HAZARD IDENTIFICATION
Sonar Bharat Environment & Ecology Pvt Ltd Page 4
Risk Analysis for BPCL LPG Bottling Plant at Durgapur, West Bengal
hole, prior to the accident. Such pressure is basically dependent on the
pressure in the vessel.
Vaporization of released liquid depends on the vapour pressure & weather
conditions. Such consideration & others have been kept in mind both
during the initial listing as well as the short listing procedure. Initial listing
of all significant inventories in the process plants was carried out
This ensured no omission through inadvertence. Based on the
methodology discussed above a set of appropriate scenarios was
generated to carry out Risk Analysis calculation, as listed below
S.NO ITEM EVENT
1 Catastrophic Rupture of 150 MT Bullet Immediate Ignition, BLEVE
2 150 MT (each) LPG Bullets Vapour Side
rupture
VCE
3 Failure of bottom line of LPG Bullet Delayed Ignition, VCE
4 Failure of LPG Compressor Delayed Ignition, VCE
5 Failure of LPG Pump Delayed Ignition, VCE
6 Flange joint leakage in LPG Pipeline Delayed Ignition, VCE
7 Tank Truck Vessel Failure BLEVE
8 Electrical Fire
9 Hygiene Events
Earthquake, extreme Wind,
Aircraft Impact
10 Rupture of filled 5,14.2, 19, 35 & 47.5 kg
cylinder
Immediate ignition and
BLEVE
Civil Disorder, strikes etc can lead to any of these releases scenarios & it
would result in similar consequences. However, these events have been
considered in the probability estimation for the release scenarios,
wherever would have significant impact.
DESCRIPTION AND PROPERTIES
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Risk Analysis For BPCL LPG Bottling Plant at Durgapur, West Bengal
SECTION –IV
DESCRIPTION AND PROPERTIES
4.0 INTRODUCTION
LPG is a mixture of commercial propane & commercial Butane which may
also contain small quantity of unsaturated hydrocarbons. LPG market in
India is governed by IS 4776 & Test methods by IS – 1148.
LPG being highly flammable may cause fire & explosion. It, therefore calls
for special attention during its handling.
PHYSICAL PROPERTIES DENSITY
LPG at atmospheric pressure & temperature is a gas which is 1.5 to
2.0 times heavier than air. It is easily liquefied under moderate
pressure. The density of liquid is approximately half that of water
and ranges from 0.507 to 0.58 m3.
Since LPG vapour pressure is heavier than air , it normally settle
down at ground level/low lying areas. This accumulation of LPG
vapour gives rise to potential fire and explosion.
VAPOUR PRESSURE
The pressure inside a LPG storage vessel is corresponding to the
temperature in storage vessel. This vapour pressure is dependent
on temperature as well as percentage composition of the mixture of
hydrocarbons present in LPG. Beyond liquid full condition in
cylinders any further expansion of the liquid will increase the
cylinder pressure by 7 – 8 kg/ m2. For each degree centigrade rise
in temperature. This clearly indicates the hazardous situation which
may arise due to overfilling of cylinder or any storage vessel.
DESCRIPTION AND PROPERTIES
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Risk Analysis For BPCL LPG Bottling Plant at Durgapur, West Bengal
FLAMMABILITY
LPG has an explosive limit range or 1.8% to 9.5% by volume of the
gas in air. This is an considerably narrower than other common
gaseous fuel.
AUTO-IGNITION TEMPERATURE.
The auto ignition temperature of LPG is around 4100 – 5480 C & will
not ignite on its own at normal temperature.
COMBUSTION
Combustion of LPG increases the volume of products in addition to
generation of heat. LPG requires about 24 to 30 times its own for
complete combustion & yields 3 – 4 times of its own volume of Co2 .
The heat of combustion is about 10,900 kcal.kg
COLOUR
LPG is colorless both in liquid and vapour phase. During leakage
and vaporization of LPG cools the atmosphere & condenses the
water vapour contained in it forming a white fog. This makes
possible to see & escape of LPG
VISCOSITY
LPG has a low viscosity (around 0.3 at 450C) & can leak when other
petroleum products cannot. This properly demands a high degree of
integrity in the pressurized systems handling LPG to avoid
Leakage.
ODOUR
LPG has a very faint smell & as such for detecting leakage of LPG
ethyl mercaptan is generally added in the ratio approx 1 kg for
mercaptan per 100 ft 3 of Liquid LPG (20 ppm)
DESCRIPTION AND PROPERTIES
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Risk Analysis For BPCL LPG Bottling Plant at Durgapur, West Bengal
TOXICITY LPG is slightly toxic. Although it is not poisonous in vapour phase, it
suffocates when present in large concentration due to displacement
of Oxygen. IDLH value of LPG is generally taken as 19000 PPM
PYROFORIC IRON
Highly inflammable pyroforic iron Sulphide is formed due to reaction
of loose iron / iron oxide with Sulphur or its compounds. Formation
of , Pyrophoric Iron Sulphide is prevented by totally eliminating
H2S, limiting the total volatile Sulphur to 0.2% by mass & reducing
loose iron oxide by thoroughly cleaning the storage vessels
internally during outage.
However, pyrophoric Iron Sulphide will spontaneously ignite in a
sphere or a cylinder due to high concentration of LPG which is
much above the upper flammable limit. When these vessels are
aired (during opening The saturation vapour pressure, flammability
range, toxicity data of Propane- Butane mixtures as well as pure
compounds are listed below
Propane (%)
Butane (%)
S.V. Process at 50C kg/Cm2
Flammability (Range (%)
Toxicity IDLH
(PPM)
Odour Threshold
(PPM)
100
- 21.12 2.1-9.5 19000 5000
70
30
19 1.9-9.5 N/A N/A
30
70 8.25 1.8-9.5 N/A N/A
20
80 7.31 1.8-9.5 N/A N/A
-
100 5.84 1.9-8.4 N/A -
DESCRIPTION AND PROPERTIES
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Risk Analysis For BPCL LPG Bottling Plant at Durgapur, West Bengal
CHEMICAL PROPERTIES
Sl.No
1 Formula C3-C4 mixture
2 Molecular Weight 51.10 Kg/KMol
3 Boiling Temperature at 1 bar (0K) 251.80K
4 Critical Temperature (0K) 357.50K
5 Critical Pressure (bar) 40 bar
6 Density ( liquid) at 450C 50.75 E+01 Kg/M3
7 Boiling Temperature 58.89 E+01 Kg/M3
8 Density ( Gas) at 1 Bar & 450C 1.93 E + 00 Kg/M3
9 At Boiling Temperature 2.44 E + 00 Kg/M3
10 Heat capacity ( Gas) at 450C 17.59 E+ 02 J/Kg/k
11 Heat of Vapourisation at 450C (J/Kg) 31.78 E + 04 J/Kg/K
12 Boiling Temperature 40.00 E/ + 02 J/Kg/K
13 Heat Combustion (J/Kg) 45.94 E+06 J/ Kg/K
14 Vapour Pressure at 450C 9.74 bar
15 Ratio of Spec heats (cp/cv) 1.11
16 Thermal Conductivity ( Gas) at 450C 1.97E-02 W/M/K
17 Boiling Temperature 0.00 E-00 W/M/K
18 Thermal Conductivity ( Liquid) at 450C 8.33 E -02 W/M/K
19 At Boiling Temperature 12.17E -02 W/M/K
20 Stoichiometric Ratio 0.036M3/M3
21 Lower Flammability Limit (% V/V) 1.80
22 Upper Flammability Limit (% V/V) 9.5
23 IDLH Valve (PPM) 19000
E (+,- numerals) = Means Power of ten of the coefficients
DESCRIPTION AND PROPERTIES
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Risk Analysis For BPCL LPG Bottling Plant at Durgapur, West Bengal
THE PHYSICAL CHEMICAL PROPERTIES OF LPG WHICH MAKE LPG
HAZARDOUS ARE AS FOLLOWS :
LPG liquid is lighter than water and hence floats on water and
evaporates
LPG vapor is heavier than Air
LPG can be stored at ambient temperatures only at higher that
atmospheric Pressure
Pressure and the actual pressure depends on the percentage of
propane in LPG
LPG is highly inflammable and forms explosive mixtures with air
LPG liquid expands to vapor phase by about 250 times
LPG has a fairly good burning velocity and explosive potential
The flame temperature is quite high and has a potential to endanger
steel structure.
With high moisture. LPG can form solid hydrates – which can Plug
pipelines, valves, regulators and other devices at lower temperatures.
Vapour pressure increases steeply with increasing temperature.
Frost bites, can occur when LPG in liquid phase comes into contact
with skin
MAXIMUM CREDIBLE ACCIDENT ANALYSIS (MCAA) APPROACH
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Risk Analysis for BPCL LPG Bottling Plant at Durgapur, West Bengal
SECTION-V MAXIMUM CREDIBLE ACCIDENT ANALYSIS (MCAA)
APPROACH 5.1 INTRODUCTION
A Maximum Credible Accident (MCA) can be characterized, as an accident with
a maximum damage potential, which is still believed to be probable.
MCA analysis does not include quantification of probability of occurrence of an
accident. Moreover, since it is not possible to indicate exactly a level of
probability that is still believed to be credible, selection of MCA is somewhat
arbitrary. In practice, selection of accident scenarios representative for a MCA-
Analysis is done on the basis of engineering judgment and expertise in the field
of risk analysis studies, especially accident analysis.
Major hazards posed by flammable storage can be identified taking recourse to
MCA analysis. This encompasses certain techniques to identify the hazards and
calculate the consequent effects in terms of damage distances of heat radiation,
toxic releases, vapor cloud explosion etc. A host of probable or potential
accidents of the major units in the complex arising due to use, storage and
handling of the hazardous materials are examined to establish their credibility.
Depending upon the effective hazardous attributes and their impact on the
event, the maximum effect on the surrounding environment and the respective
damage caused can be assessed.
As an initial step in this study, a selection has been made of the processing and
storage units and activities, which are believed to represent the highest level of
risk for the surroundings in terms of damage distances. For this selection,
following factors have been taken into account:
Type of compound viz. flammable or toxic
Quantity of material present in a unit or involved in an activity and
MAXIMUM CREDIBLE ACCIDENT ANALYSIS (MCAA) APPROACH
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Risk Analysis for BPCL LPG Bottling Plant at Durgapur, West Bengal
Process conditions such as temperature, pressure, flow, mixing and
presence of incompatible material
In addition to the above factors, location of a unit or activity with respect to
adjacent activities is taken into consideration to account for the potential
escalation of an accident. This phenomenon is known as the Domino Effect. The
units and activities, which have been selected on the basis of the above factors,
are summarized, accident scenarios are established in hazard identification
studies, whose effect and damage calculations are carried out in Maximum
Credible Accident Analysis Studies.
5.2 METHODOLOGY
Following steps are employed for visualization of MCA scenarios: Chemical inventory analysis
Identification of chemical release and accident scenarios
Analysis of past accidents of similar nature to establish credibility to
identified scenarios; and
Short-listing of MCA scenarios
5.3 COMMON CAUSES OF ACCIDENTS
Based on the analysis of past accident information, common causes of accidents
are identified as:
Poor house keeping
Improper use of tools, equipment, facilities
Unsafe or defective equipment facilities
Lack of proper procedures
Improvising unsafe procedures
Failure to follow prescribed procedures
Jobs not understood
Lack of awareness of hazards involved
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Lack of proper tools, equipment, facilities
Lack of guides and safety devices, and
Lack of protective equipment and clothing
5.4 FAILURES OF HUMAN SYSTEMS
An assessment of past accidents reveal human factor to be the cause for over
60% of the accidents while the rest are due to other component failures. This
percentage will increase if major accidents alone are considered for analysis.
Major causes of human failures reported are due to:
Stress induced by poor equipment design, unfavorable environmental
conditions, fatigue, etc.
Lack of training in safety and loss prevention
Indecision in critical situation; and
Inexperienced staff being employed in hazardous situation
Often, human errors are not analyzed while accident reporting and accident
reports only provide information about equipment and/or component failures.
Hence, a great deal of uncertainty surrounds analysis of failure of human
systems and consequent damages.
5.5 MAXIMUM CREDIBLE ACCIDENT ANALYSIS (MCAA)
Hazardous substances may be released as a result of failures or catastrophes,
causing possible damage to the surrounding area. This section deals with the
question of how the consequences of release of such substances and the
damage to surrounding area can be determined by means of models.
It is intended to give an insight into how the physical effects resulting from
release of hazardous substances can be calculated by means of models and
how vulnerability models can be used to translate the physical effects in terms of
injuries and damage to exposed population and environment. A disastrous
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Risk Analysis for BPCL LPG Bottling Plant at Durgapur, West Bengal
situation in general is due to outcome of fire, Vapor Cloud explosion in addition
to other natural causes, which eventually lead to loss of life, property and
ecological imbalance.
Major hazards posed by flammable storage can be identified taking recourse to
MCA analysis. MCA analysis encompasses certain techniques to identity the
hazards and calculate the consequent effect in terms of damage distances of
heat radiation, toxic release, vapor cloud explosion etc. A host of probable or
potential accidents of the major units in the complex arising due to use, storage
and handling of the hazardous materials are examined to establish their
credibility. Depending upon the effective hazardous attributes and their impact
on the event, the maximum effect on the surrounding environment and the
respective damage caused can be assessed. The MCA analysis involves
ordering and ranking various sections in terms of potential vulnerability. 5.6 PHYSICAL EFFECTS AND CONSEQUENCES
Using the failure case data developed the program undertakes consequences
calculation for each indentified incident or failure case. The software initially
models the dispersion of the released material irrespective of whether it is
flammable or toxic. For flammable materials the software then proceeds to
determine the effect zones for the various possible outcomes of such release.
The risk analysis must account for all these possible outcomes. The possible
consequences include.
Fireball / BLEVE
Heavy Cloud Dispersion
Jet Fire
Vapor Cloud Explosion
The particular outcomes modeled depend on the behavior of the release and the
dilution regimes which exist. This can be quite complex. The program
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undertakes these calculations for the representative meteorological condition as
suitable for the meteorological condition in the area.
Consequential effects of the accidental release of a chemical are:
Intensity of heat radiation due to a fire or a fireball or BLEVE as a
function of the distance of source
Energy of vapor cloud explosion as a function of the distance of the
exploding cloud.
Concentration of gaseous material in the atmosphere due to the
dispersion of the evaporated material. The letter can be either an
explosive or a toxic material.
A release can ignite as the result of the event, which causes it, or can ignite
close to the source before the flammable cloud has travelled away from the
source. Immediate ignition can result in a fireball or a BLEVE or pool fire
depending on the nature and spread of release. A fireball can occur when there
is a specific type of fireball resulting raises the internal pressure and weakens
the vessel shell unit it bursts open and releases its entire contents as large and
very intense fireball.
If the material does not ignite immediately, allowing spill / release to form a liquid
pool a flammable gas cloud may be formed thorough evaporation of the pool due
to combination of solar heat, ground heat and heat from the neighbouring
environment and it can ignite at a number of points downwind if its path is such
that it goes across ( for example , a road an area where people are present or
other ignition sources). Delayed ignition can result in wide spread damaging
vapor cloud explosion of high energy or minor flash fire of limited energy
depending on the quantity of flammable vapor. The accident scenarios are
normally divided into the following categories of the chemicals according to their
physical state / phase, pattern of release , nature of dispersion, physical effects
and damage:
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Risk Analysis for BPCL LPG Bottling Plant at Durgapur, West Bengal
a. Release of a gas ( Flammable or toxic or both )
b. Release of a liquid ( Flammable or toxic or both )
c. Release of a liquefied gas ( Flammable or toxic or both )
Event trees are the simplified schemes of consequence, which show the
possible evolution of effects after the release of the material. Such trees are very
effective in determining the possible consequences.
5.7 CONSEQUENCE MODELLING
Accidental release of' flammable or toxic vapors can result in severe
consequences. Delayed ignition of flammable vapors can result in blast
overpressures covering larger areas. This may lead to extensive loss of life &
property. Toxic clouds may cover yet a larger distance due to the lower threshold
values in relation to those in case of explosive clouds (the lower explosive
limits). In contrast, fires have localized consequences. Fires can be put out or
contained in most cases; there are few mitigating actions one can take once a
vapor cloud gets released
If LPG is released into the atmosphere, it may cause damage due to resulting
BLEVE, fires or vapor cloud explosion of the evaporated LPG. To formulate a
structured approach to identification of hazards and understanding of
contributory factors is essential. These factors have been described in detail.
DAMAGE CRITERIA
In consequence analysis, use is made of a number of calculation models to
estimate the physical effects of an accident (spill of hazardous material) & to
predict the damage (lethality, injury, material destruction) of the effects. The
calculations can roughly be divided in three major groups:
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Risk Analysis for BPCL LPG Bottling Plant at Durgapur, West Bengal
a) Determination of the source strength parameters.
b) Determination of the consequential effects.
c) Determination of the damage or damage distances.
The basic physical effect models consist of the following
SOURCE STRENGTH PARAMETERS
Calculation of the outflow of liquid, vapors or gas out of a vessel or
a pipe, in case of rupture. Also two-phase outflow can be
calculated
Calculation, in case of liquid outflow, of the instantaneous flash evaporation & of the dimensions of the remaining liquid pool.
Calculation of the evaporation rate, as a function of volatility of the material, pool dimensions & wind velocity
Source strength equals pumps capacities, etc in came cases.
CONSEQUENTIAL EFFECTS
Dispersion of gaseous material in the atmosphere as a function of source
strength, relative density of the gas, weather conditions & topographical
situation of the surrounding area.
Intensity of heat radiation ( KW/M2) due to fire or a BLEVE, as a function
of distance of the source
Energy of vapor cloud explosions [in N/M2], as a function of the distance
to the distance of the exploding cloud
Concentration of gaseous material in the atmosphere, due to the
dispersion of evaporated chemical. The tatter can be either explosive or
toxic.
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It may be obvious, that the types of models that must be used in a specific risk
study strongly depend upon the type of material involved
Gas, vapor, liquid, solid?
Inflammable, explosive, toxic combustion products?
Stored at high /low temperatures or pressure?
Controlled outflow (Pump Capacity) or catastrophic failure ?
SELECTION OF DAMAGE CRITERIA
The damage criteria give the relation between extent of the physical effects
(exposure) & the percentage of the people that will be killed or injured due to
those effects. The knowledge about these relations depends strongly on the
nature of the exposure. For instance, much more is known about the damage
caused by heat radiation, than about the damage due to toxic exposure, & for
these toxic effects, the knowledge differs strongly between different materials. In
consequences Analysis studies, in principle three types of exposure to hazardous
effects are distinguished:
Effects are distinguished
I. Heat radiation from a jet, pool fire, a flash or a BLEVE
II. Explosion
III. Toxic effects, from toxic material or toxic combustion products
In a LPG bottling plant as there are no toxic chemicals handled. In the next two
paragraphs, the chosen damage catena are given & explained for heat radiation
& vapor cloud explosion
HEAT RADIATION
The consequences of exposure to heat radiation are a function of:
The radiation energy into the human body ( KW/M2)
The exposure duration [sec]
The protection of the skin tissue ( clothed or naked body)
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The limits for 1% of the exposed people to be killed due to heat radiation & for
second degree bums are given in the table below
DAMAGES TO HUMAN LIFE DUE TO HEAT RADIATION
Since in practical situations, only the own employees will be exposed to heat
radiation in cases of a fire, it is reasonable to assume the protection by clothing. It
can be assumed that people would be able to find a cover or a shield against
thermal radiation 10 sec time. Furthermore, 100% lethality may be assumed for
all people suffering from direct contact with flames, such as the pool fire, a flash
fire or a jet flame. The effects relatively lesser incident radiation intensity is given
below:
EFFECTS DUE TO INCIDENT RADIATION INTENSITY
THERMAL RADIATION (KW/M2)
TYPE OF DAMAGE
0.7
EQUIVALENT TO SOLAR RADIATION
1.6
NO DISCOMFORT FOR LONG EXPOSURE
4.0
SUFFICIENT TO CAUSE PAIN WITHIN 20 SEC BLISTERING OF SKIN (1ST DEGREE BURNS ARE LIKELY)
9.5
PAIN THRESHOLD REACHED AFTER 8 SEC 2ND DEGREE BURN AFTER 20 SEC
12.5 MINIMUM ENERGY REQUIRED FOR PILOTED IGNITION OF WOOD, MELTING PLASTIC TUBING ETC
The actual results would be less severe due to the various assumptions made in
the models arising out of the flame geometry, emissivity, angle of incidence,
view factor & others. Upon ignition , a spilled liquid hydrocarbon would be burn in
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the form of a large turbulent diffusion flame the size of the flame would be
depend upon the spill surface & the thermo - chemical properties of the spilled
liquid. In particular, the diameter of the fire (if not confined to a dyke), the visible
height of the flame, the tilt & drag of the flame due to wind can be correlated to
the burning velocity of the liquid. The radiative output, of the flame would be
dependent upon the fire size, extent of mixing with air & the flame temperature.
Some fraction of the radiation is absorbed by carbon dioxide & water vapor in
the intervening atmosphere. In addition, large hydrocarbon pool fires produce
thick smoke, which can significantly obscure flame radiation. Finally the incident
flux at an observer location would depend upon the radiation view factor .which
is a function of the distance from the flame surface, the observer's orientation &
the flame geometry Estimation of the thermal radiation hazards from the pool
fires essentially involves 3 steps; characterization of flame geometry,
approximation of the radiative properties of the fire & calculation of safe
separation distances to specified levels of thermal radiation
EXPLOSION In case of vapor cloud explosion, two physical effects may occur
A flash fire over the whole length of the explosive gas cloud.
A blast wave , with typical peak overpressures circular around ignition
source
As explained above, 100% lethality is assumed for all people who are present
within the cloud proper.
For the blast wave the lethality criterion is based on
A peak overpressure of 0.1 bar will cause serious damage to 10% of the
housing / structures
Falling fragments will kill one of each eight persons in the destroyed
buildings
The following damage criteria may be distinguished with respect to the peak
overpressures resulting from the blast wave:
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DAMAGE DUE TO OVERPRESSURES
PEAK OVERPRESSURE
DAMAGE TYPE
0.83 BAR
TOTAL DESTRUCTION
0.30 BAR
HEAVY DAMAGE
0.10 BAR
MODERATE DAMAGE
0.03 BAR
SIGNIFICANT DAMAGE
0.01 BAR
MINOR DAMAGE
From this it may be concluded that p=0.17 E+5 pa corresponds approximately
with 1% lethality. Furthermore it is assumed that everyone inside an area in
which the peak overpressure is greater than 0.17 E+5 pa will be wounded by
mechanical damage. For the gas cloud explosion this will be inside a circle with
the ignition source as its center
EXTERNAL EVENTS
External events can initiate & contribute to potential incidents considered in a
Risk Analysis. Although the frequency of such events is generally low, they may
result in a major incident. They also have the potential to initiate common cause
failures that can lead to escalation of the incident. External events can be
subdivided into two main categories.
Natural hazards : Earthquakes , Floods, Tornadoes, extreme temperature,
lightening etc
Man induced events : Aircraft crash, missile, nearby industrial activity,
sabotage etc
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TECHNOLOGY
Normal design codes for gas/chemical plants have sufficient safety factors to
allow the plant to withstand major external events to a particular level (e.g.
intense loading of say 120 mph). Quantitative design rules usually used for
seismic events, flooding, tornadoes & extreme wind hazards as follows
SEISMIC –The design should withstand critical ground motion with an
annual
Probability of 10-4 or less
FLOODING – The design should withstand the efforts of worst
flooding occurrence in 100 year period
WINDS - The design should withstand the most critical combination
of Wind velocity & duration having a probability of 0.005 or less in a 50
year period (annual probability of 10-4 or less).
DAMAGE DUE TO INCIDENT RADIATION INTENSITY
INCIDENT RADIATION
(KW/M2)
TYPE OF DAMAGE
62.0
Spontaneous Ignition Of Wood & Sufficient To Cause Damage To Process Equipments
37.5
Minimum energy required to ignite wood at infinitely long exposure ( Non plastic )
12.5
Minimum energy required for piloted ignition if wood, melting plastic tubing, etc
4.5
Sufficient to cause pain to personal if unable to reach cover within the 20 seconds. However blistering of skin ( 1st degree burn is likely)
1.6 Will cause no discomfort to long exposure.
0.7
Equipment to solar radiation.
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PHYSIOLOGICAL EFFECTS OF THRESHOLD THERMAL DOSES
DOSE THRESOLD (KW/M2)
EFFECT CONSEQUENCES
37.5 3RD DEGREE BURN INVOLVE WHOLE OF DPIDERMIS AND DERMIS; SUB- CUTANEOUS TISSUES MAY ALSO BEDAMAGED.
12.5 2ND DEGREE BURN INVOLE WHOLE OF EPIDERMIS OVER THE AREA OF THE BURN PLUS SOME PORTION OF DERMIS.
4.0 1ST DEGREE BURN INVOLE ONLY EPIDERMES, BLISTER MAY OCCUR, EXAMPLE SUNBURNS.
DAMAGE EFFECTS OF BLAST OVERPRESSURE
BLAST OVER PRESSURE
(Bar)
DAMAGE LEVEL
0.3 Major structure damage ( assumed fatal to people inside building or within the other structures
0.1 Storage failure
0.01 Eardrum Rupture
0.03 Repairable damage, pressure Vessels light structure collapse
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POSSIBLE RELEASE SCENARIO OF LPG
PIPELINE RELEASE RUPTURE OF VESSEL
VAPOR LIQUID
OUTFLOW
JET FIRE DISPERSION
DELAYED IGNITION
NO IGNITION
VCE/ FLASH FIRE
SAFE DISPERSION
BLEVE
OUTFLOW MODEL
TWO PHASE OUTFLOW
JET FIRE LIQUID SPREADING AND EVAPORATION
DISPERSION
POOL FIRE
DELAYED IGNITION
NO IGNITION
VCE/ FLASH FIRE
SAFE DISPERSION
HAZARDS OF LPG SPILLAGE / ESCAPE FROM CONTAINMENT
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Risk Analysis For BPCL LPG Bottling Plant at Durgapur, West Bengal
SECTION-VI HAZARDS OF LPG SPILLAGE / ESCAPE FROM
CONTAINMENT 6.0 General
When LPG is released from a storage vessel or a pipeline , a fraction of LPG
vaporizes immediately and the other portion forms a pool if the released liquid
quantity is more. LPG from the pool vaporizes rapidly entrapping some liquid as
droplets as well as considerable amount of air forming a gas cloud. The gas
cloud is relatively heavier than air and forms a thin layer on the ground. The
cloud flows into trenches and depressions and in this way travels a considerable
distance.
As the cloud formed in the area of spill moves downwind under influence of
wind, it gets diluted. A small spark, when the vapour cloud is within the
flammability limit can cause flash fire, explosion and if the liquid pool still exist
and remains in touch of cloud under fire it can ignite the whole mass of liquid.
However in case of non existence of any source of ignition there will be no
occurrence of hazardous event and the cloud may get diluted to such a level that
the mixture is no longer explosive. However , it can cause asphyxiation due to
displacement of oxygen . Different types of combustion reactions . associated in
case of. release of LPG from the containment are listed in the following sections.
JET FIRE
Escaping jet of LPG from pressure vessels / piping, if ignited cause a jet flame.
The jet flame direction and tilt depend on prevailing wind direction and velocity.
Damage, in case of such type of jet fires, is restricted to within the- plant
boundary. However, the ignited jet can impinge on other vessels and
equipment carrying LPG and cause domino effect.
HAZARDS OF LPG SPILLAGE / ESCAPE FROM CONTAINMENT
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Risk Analysis For BPCL LPG Bottling Plant at Durgapur, West Bengal
POOL FIRE
The liquid pool, if ignited , causes a "Pool Fire" . In the pool fire, LPG burns with
long smoky flame throughout the pool diameter radiating intense heat which
creates severe damage to the adjoining buildings, structures , other vessels and
equipment causing secondary fires. The flame .may tilt under influence of wind
and may get propagated / brown several pool diameters down wind. Damage, in
case of such fires ,is restricted within the plant area and near the source of
generation.
UNCONFINED VAPOUR CLOUD EXPLOSION (UVCE)
Clouds of LPG vapour mixed with air (within flammability limit) may cause
propagating flames when ignited. In certain cases flame take place within
seconds the thermal radiation intensity is severe depending on the total mass of
LPG in the cloud and may cause secondary fires. When the flame travels very
fast it explodes high over pressures or blast effects causing heavy damage at
considerable distance from the release point. Such explosions are called
unconfined vapour cloud explosion.
BOILING LIQUID EXPANDING VAPOUR EXPLOSION (BLEVE)
This phenomenon occurs when pressure inside a storage vessel increases
above the design pressure due to a fire in the adjacent area. Due to
impingement of flame or due to radiant heat, temperature in the vapour portion
of the storage vessel increases rapidly compared to the portion filled with liquid.
Increase in temperatures softens and weakens the metal wall of the shell. With
the rise in vapour pressure and inadequate vapour space for expansion , the
shell of storage tanks bursts causing fragments of the shell flying like projectiles
with release of whole mass of pressurized boiling liquid. The released liquid
flashes and atomies immediately often resulting a large fire ball in contact with
HAZARDS OF LPG SPILLAGE / ESCAPE FROM CONTAINMENT
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Risk Analysis For BPCL LPG Bottling Plant at Durgapur, West Bengal
an ignited source. Although the fire ball lasts only a few seconds , its effect is
devastating due to flame contact and intense thermal radiation. This
phenomenon is called BLEVE. The effect of BLEVE extends beyond the plant
boundary in case of catastrophic failure of large pressurized storage vessels.
PAST LPG INCIDENTS IN INDIA
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Risk Analysis For BPCL LPG Bottling Plant at Durgapur, West Bengal
SECTION –VII
HISTORY OF PAST ACCIDENTS IN LPG PLANTS IN INDIA
A. HARYANA, 1973
Road accident: A truck carrying 300 LPG cylinders on National Highway 20
miles away from Delhi .capsized 8. LPG cylinders tumbled down. Suspected
cause of fire is friction between the cylinders which might have leaked due to
rolling down . 1 person died & 3 others were injured
B. MADRAS , 04.04.1981
Fire Accident at LPG Filling Plant at Madras Refineries Limited . On the
day of the fire no filling operation was planned . However it was planned to
do some housekeeping & cleanup operations & interacting of cylinders &
stacking . A truck was also engaged to remove defective cylinders. Prior to
the removal of defective cylinders , reported that about 4500 cylinders
were lying there . Till the truck arrived the contract workmen were engaged
in shifting cylinders by rolling to the new stacking location & they removed
about 400 cylinders & had been stacking them . The truck also made one
trip , of intercarting of 265 cylinders to the new location. , The truck made a
second trip , picked up about 230cylinders & came to the stacking location
& stood by , ready to unload the cylinders . At this time the fire broke out
from the middle of the new stack of defective cylinders & spread fast to the
entire stack of cylinders . In a matter of minutes cylinders had started to
burst with a loud noise due to exposure to intense heat of fire & several
cylinders gave way due to over pressuring . Sudden bursting of cylinders
led the splinters / metal pieces to fly off in all odd directions quite far away
from the accident spot. Due to bursting of cylinders & spreading of fire, the
truck also caught fire & with its full load of cylinders was gulfed in fire &
was totally destroyed. Smoking is believed to be the cause of this accident
B. DELHI, 15.05.1983
PAST LPG INCIDENTS IN INDIA
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A large fire occurred in LPG Bottling Plant filling 9000 cylinders per day , in two shift operation . LPG was supplied to the plant in tank wagons
The fire originated from the cylinder repair area . Leaked LPG got ignited by the lighted beedi, which one of the workers, in the repair area ,was smoking while he was carrying decanting operations 4 persons died & 25 were injured. About 80665 cylinders were damaged.
D. MADRAS, 1985
Fire accident occurred in one of the restaurants when one of the untrained
workers attempted to disconnect an empty cylinder from the pigtail
connection for fixing a filled LPG cylinder. 7 people died & 10 others were
injured
E. SALEM
LPG gas leak was observed through the improperly closed gate valve near
the top manhole, in a railway wagon . Due to timely action a big fire
accident could be averted.
F. NELLORE 1988
Tanker carrying LPG cylinders burst into flames right under the Nellore
railway bridge, melting the electric traction wire to a span of 45 m &
completely twisting the track over the bridge. 1 person died & 2 others
were injured
G. CHANDIGARH, 1989
An accident occurred in a LPG Plant , when some employees of LPG
agency were trying to pilfer LPG from one cylinder to another when the
leaking gas got ignited from the open fire nearby . Two people died & no
one was reported injured.
H. RAJKOT.1989
PAST LPG INCIDENTS IN INDIA
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Risk Analysis For BPCL LPG Bottling Plant at Durgapur, West Bengal
Indian Oil Corporation LPG bottling Plant: A LPG leakage incident
involving a LPG road tanker took place at the IOCL .The locking pin of the
shut off valve of the liquid line of the tanker was broken . Since the valve
after being opened, could not be closed, LPG started leaking . 2 people
were injured.
I. RONALI, BARODA, 1989
Another LPG leakage incident involving a road tanker occurred because the gasket used in the liquid line of the tanker had worn out & gave way leading to leakage of LPG.
J. DHULE, MAHARASHTRA, 1990
Another LPG incident involving road tankers took place when the driver of
the tanker lost control & the vehicle fell into a ditch leading to the shearing
of excess flow check valve & safety valve of the tank resulting in the
leakage of LPG. The cloud traveled a distance of 100 m away & met with a
source of ignition resulting in flash fire. 12 people died in this accident.
K. HOWRAH, BRIDHE, CALCUTTA, 1990
A road tanker carrying 12.45 MT of LPG overturned on Howrah bridge &
the roto gauge was damaged & the gas leak occurred. Due to prompt
safety measures taken by the fire brigade, an explosion was averted. Two
people were injured in this incident.
L. BONTHAPALLY ,AP,1990
PAST LPG INCIDENTS IN INDIA
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There was a gas leak from a faulty valve. At the same time static charge
accumulated on the tanker during unloading. Since the tanker was not
"earthed" electrostatic arcing occurred & resulted in an explosion & the
entire vehicle was burnt. Nobody was hurt.
M. GANAURSI, PUNJAB, 1990
Yet another LPG road tanker incident, a tanker overturned & the safety
valve got damaged resulting in a gas leak which enveloped an entire
village. The gas got ignited on coming in contact with some flame &
resulted in a massive fire. 31 People died & 30 others were injured.
N. JAMSHEDPUR, 1991
Due to damage in the terflon packing around the thermowell connecting
the nozzle to the Horton sphere thermoweli was displaced resulting in a
leak. One person was injured
O. PUNE, 1992
Since the liquid discharge valve was not closed properly after the
unloading of LPG from the tanker, liquid LPG leaked out. The vapors from
the leak, reached the workers quarters, & got ignited. The flames reached
the tanker, which caught fire. One person died & two others were injured.
CONSEQUENCE ANALYSIS
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Risk Analysis For BPCL LPG Bottling Plant Durgapur, West Bengal
SECTION –VIII
CONSEQUENCE ANALYSIS
8.0 BASIC ASSUMPTION FOR CALCULATING EFFECT ZONE
PRODUCT : LPG ( 60% Butane and 37.4% Propane by weight ),
Molecular Weight : 52, Vapour pressure: 7.72 Bar at 448 K, LEL: 1.8%,
UEL: 9.5%, Boiling Point: -17Deg C at 1 Bar, Liquid Density : 0.521 Kg/
M3, Heat Capacity : 2736 J/KG/K,
PROPANE:- Heat of Combustion: 4.65 E+07 J/ KG, Heat of Evaporation
at Boiling Temp ( 231 K at 1 Bar) : 2.22 E +03 J/KG. K
Butane:- Heat of Combustion : 4.59E + 07 J/ KG, Heat of Evaporation at
Boiling Temperature ( 273 K at 1 Bar ): 3.84 E + 05 J/KG
METEOROLOGICAL DATA
A. Temperature
Summer (0 c) 26 – 37.4 Winter (0 c) 12 – 17.5 Humidity: 44%- 70%
Tanker Bullet Size : 18 Tons Bullet Capacity : 150 MT x 3
300 MT x 2 (Proposed)
Pipeline Data
Liquid Line dia from tanker to bullet : 150mm
Liquid Line dia from bullet to pump : 100mm
Liquid Line dia from pump to carousal : 100mm
Return vapour line dia : 100mm
Dia of return pipeline from carousal : 100mm
Dia of vapour return line from carousal : 50mm
CONSEQUENCE ANALYSIS
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Risk Analysis For BPCL LPG Bottling Plant Durgapur, West Bengal
Pump Capacity :
LPG Pump Capacity : 50 M3/Hr x2
Jockey Pump Capacity : 10 M3/Hr x2
Fire water Pump Capacity : 616 Kl/Hr x2
Compressor Capacity
Air Compressor Capacity : 100 CFM x 2
198 CFM x 2 LPG Compressor Capacity : 150 CFM x 1
65 CFM x 2
CONSEQUENCE CALCULATION: Please consider; Storage Temperature : 293 K; Storage Pressure : 5.5 Kg/ Cm2,
Discharge Coeff: 0.6, Wind Speed: 1.3 M/ sec, Atm Stability : F
BLEVE:
Source : a) 18 MT Bullet Truck
b) 150 MT Bullet ( Vessel- in open pedestal)- full capacity
HEAVY CLOUD DISPERSION (dispersion LEL distance considering
Release Time of 1800 Sec )
Source : a) 150 mm liquid line rupture (100%) from bullet truck
b) 100 mm liquid line rupture (100%) to carousal
c) 100 mm vapour line rupture (25%) from bullet truck
d) 100 mm liquid line rupture (25%) to carousal
e) 100 mm liquid line rupture (100%) from bullet trucl to pump
f) 100 mm liquid line rupture (25%) from bullet suction
g) 100 mm vapour line rupture (100%) from bullet truck
h) 100 mm vapour return hrader under compression
i) 100 mm carousal return line (liquid)
j) 50 mm carousal return line (vapour)
CONSEQUENCE ANALYSIS
Page 3
Risk Analysis For BPCL LPG Bottling Plant Durgapur, West Bengal
VAPOUR CLOUD EXPLOSION
Source : a) 150 mm liquid line rupture from bullet truck (100%)
b) 100 mm liquid line rupture to carousal (100%)
c) 150 mm liquid line rupture from bullet truck (25%)
d) 100 mm liquid line rupture to carousal (25%)
e) 100 mm liquid line rupture (100%) from bullet suction
f) 100 mm liquid line rupture from bullet suction (25%)
g) 100 mm carousal return line liquid
JET FIRE ( if ignited) ,
Source : a) 150 mm liquid line rupture from bullet truck (100%)
b) 100 mm liquid line rupture to carousal
c) 100 mm vapour line rupture from bullet truck (100%)
d) 100 mm liquid line rupture from bullet suction (100%)
e) 100 mm vapour return header under compressor
f) 100 mm carousal return line (liquid)
g) 50 mm unloading arm rupture (liquid)
GASKET FAILURE :
Source : a) 100 mm Gasket failure in LPG pump discharge
b) 100 mm Gasket Failure in LPG pump discharge (25%)
CONSEQUENCE ANALYSIS
Page 4
Risk Analysis For BPCL LPG Bottling Plant Durgapur, West Bengal
SCENARIO -1
BLEVE - 5 KG CYLINDER
ASSUMPTION 1. AMBIENT TEMPERATURE : 37.4 (0C)
2. AMOUNT OF GAS : 5 (KG)
3. DIAMETER CLOUD : Nil
4. DURATION OF FIRE BALL : Nil
5. INTENSITY OF RADIATION : Nil
6. RELATIVE HUMIDITY : 44%
THE THERMAL LOAD IS CALCULATED FROM THE CENTRE OF THE FIRE BALL
SL.NO THERMAL RADIATION DISTANCE (M)
1 1st Degree Burn ( 4KW/M2) Quantity insufficient for BLEVE
2 50% LETHALITY ( 12.5KW/M2) Quantity insufficient for BLEVE
3 100% LETHALITY ( 37.5KW/M2) Quantity Insufficient for BLEVE
CONSEQUENCE ANALYSIS
Page 5
Risk Analysis For BPCL LPG Bottling Plant Durgapur, West Bengal
SCENARIO -2
BLEVE - 14.2 KG CYLINDER
ASSUMPTION
1. AMBIENT TEMPERATURE : 37.4 (0C)
2. AMOUNT OF GAS : 14.2 (KG)
3. DIAMETER CLOUD : Nil
4. DURATION OF FIRE BALL : Nil
5. INTENSITY OF RADIATION : Nil
6. RELATIVE HUMIDITY : 44%
THE THERMAL LOAD IS CALCULATED FROM THE CENTRE OF THE FIRE BALL
SL.NO THERMAL RADIATION DISTANCE (M)
1 1st Degree Burn ( 4KW/M2) Quantity insufficient for BLEVE
2 50% LETHALITY ( 12.5KW/M2) Quantity insufficient for BLEVE
3 100% LETHALITY ( 37.5KW/M2) Quantity Insufficient for BLEVE
SL.NO Cylinder Capacity
(kg)
Failure During Overheating
Total Energy
(KL)
Max. Fragment
range (m)
Fragment
Velocity (m/s)
1 14.2
12.5 162.2 39.8
CONSEQUENCE ANALYSIS
Page 6
Risk Analysis For BPCL LPG Bottling Plant Durgapur, West Bengal
SCENARIO -3
BLEVE -- 19 KG CYLINDER
ASSUMPTION 1. AMBIENT TEMPERATURE : 37.4 (0C)
2. AMOUNT OF GAS : 19 (KG)
3. DIAMETER CLOUD : Nil
4. DURATION OF FIRE BALL : Nil
5. INTENSITY OF RADIATION : Nil
6. RELATIVE HUMIDITY : 44%
THE THERMAL LOAD IS CALCULATED FROM THE CENTRE OF THE FIRE BALL
SL.NO THERMAL RADIATION DISTANCE (M)
1 1st Degree Burn ( 4KW/M2) Quantity In sufficient for BLEVE
2 50% LETHALITY ( 12.5KW/M2) Quantity In sufficient for BLEVE
3 100% LETHALITY ( 37.5KW/M2) Quantity In sufficient for BLEVE
CONSEQUENCE ANALYSIS
Page 7
Risk Analysis For BPCL LPG Bottling Plant Durgapur, West Bengal
SCENARIO -4
BLEVE -- 35 KG CYLINDERS
ASSUMPTION 1. AMBIENT TEMPERATURE : 37.4 (0C)
2. AMOUNT OF GAS : 35 (KG)
3. DIAMETER CLOUD : Nil
4. DURATION OF FIRE BALL : Nil
5. INTENSITY OF RADIATION : Nil
6. RELATIVE HUMIDITY : 44%
THE THERMAL LOAD IS CALCULATED FROM THE CENTRE OF THE FIRE BALL
SL.NO THERMAL RADIATION DISTANCE (M)
1 1st Degree Burn ( 4KW/M2) Quantity In sufficient for BLEVE
2 50% LETHALITY ( 12.5KW/M2) Quantity In sufficient for BLEVE
3 100% LETHALITY ( 37.5KW/M2) Quantity In sufficient for BLEVE
SL.NO Cylinder
Capacity (kg)
Failure During Overheating
Total Energy
(KL)
Max. Fragment
range (m)
Fragment Velocity
(m/s)
1 35
31.4 131.2 43.3
CONSEQUENCE ANALYSIS
Page 8
Risk Analysis For BPCL LPG Bottling Plant Durgapur, West Bengal
SCENARIO -5
BLEVE – 47.5 KG CYLINDERS
ASSUMPTION 1. AMBIENT TEMPERATURE : 37.4 (0C)
2. AMOUNT OF GAS : 47.5 (KG)
3. DIAMETER CLOUD : Nil
4. DURATION OF FIRE BALL : Nil
5. INTENSITY OF RADIATION : Nil
6. RELATIVE HUMIDITY : 44%
THE THERMAL LOAD IS CALCULATED FROM THE CENTRE OF THE FIRE BALL
SL.NO THERMAL RADIATION DISTANCE (M)
1 1st Degree Burn ( 4KW/M2) Quantity In sufficient for BLEVE
2 50% LETHALITY ( 12.5KW/M2) Quantity In sufficient for BLEVE
3 100% LETHALITY (37.5KW/M2) Quantity In sufficient for BLEVE
SL.NO Cylinder Capacity
(kg)
Failure During Overheating
Total Energy
(KL)
Max. Fragment
range (m)
Fragment Velocity
(m/s)
1 47.5
42.4 199.2 44.2
CONSEQUENCE ANALYSIS
Page 9
Risk Analysis For BPCL LPG Bottling Plant Durgapur, West Bengal
SCENARIO -6
BLEVE - 18 MT BULLET TRUCK
ASSUMPTION 1. AMBIENT TEMPERATURE : 37.4 (0C)
2. AMOUNT OF GAS : 18 MT
3. RADIUS OF FIRE BALL : 62.5 (M)
4. DURATION OF FIRE BALL : 8.8 (S)
5. INTENSITY OF RADIATION : 191.9 (KW/M2)
6. RELATIVE HUMIDITY : 44%
THE THERMAL LOAD IS CALCULATED FROM THE CENTRE OF THE FIRE BALL
SL.NO THERMAL RADIATION DISTANCE (M)
1 1st Degree Burn ( 4KW/M2) 318.3
2 50% LETHALITY ( 12.5KW/M2) 195.2
3 100% LETHALITY ( 37.5KW/M2) 115.3
CONSEQUENCE ANALYSIS
Page 10
Risk Analysis For BPCL LPG Bottling Plant Durgapur, West Bengal
SCENARIO - 7
BLEVE -150 MT BULLET
ASSUMPTION 1. AMBIENT TEMPERATURE : 37.4 (0C)
2. AMOUNT OF GAS : 150 MT
3. RADIUS OF FIRE BALL : 124.4(M)
4. DURATION OF FIRE BALL : 15.3 (S)
5. INTENSITY OF RADIATION : 232.3(KW/M2)
6. RELATIVE HUMIDITY : 44%
THE THERMAL LOAD IS CALCULATED FROM THE CENTRE OF THE FIRE BALL
SL.NO THERMAL RADIATION DISTANCE (M)
1 1st Degree Burn ( 4KW/M2) 673.4
2 50% LETHALITY ( 12.5KW/M2) 413.6
3 100% LETHALITY ( 37.5KW/M2) 244.6
CONSEQUENCE ANALYSIS
Page 11
Risk Analysis For BPCL LPG Bottling Plant Durgapur, West Bengal
SCENARIO – 8
BLEVE -300 MT MSV
ASSUMPTION 1. AMBIENT TEMPERATURE : 37.4 (0C)
2. AMOUNT OF GAS : 300 MT
3. RADIUS OF FIRE BALL : 187.2(M)
4. DURATION OF FIRE BALL : 20.4 (S)
5. INTENSITY OF RADIATION : 232.3(KW/M2)
6. RELATIVE HUMIDITY : 44%
THE THERMAL LOAD IS CALCULATED FROM THE CENTRE OF THE FIRE BALL
SL.NO THERMAL RADIATION DISTANCE (M)
1 1st Degree Burn ( 4KW/M2) BLEVE is not possible
2 50% LETHALITY ( 12.5KW/M2) BLEVE is not possible
3 100% LETHALITY ( 37.5KW/M2) BLEVE is not possible
CONSEQUENCE ANALYSIS
Page 12
Risk Analysis For BPCL LPG Bottling Plant Durgapur, West Bengal
SCENARIO – 9
HEAVY CLOUD DISPERSION – 150 MM LIQUID LINE RUPTURE (100% )
FROM BULLET TRUCK
ASSUMPTION 1. AMBIENT TEMPERATURE : 12 (0C)
2. PIPE DIA : 150MM
3. FLOW RATE : 380.4 (Kg/Sec)
4. RELEASE TIME : 1800 SEC
5. PUMPING PRESSURE : 12 Kg/CM2
6. RELATIVE HUMIDITY : 70%
DISTANCES FOR DISPERSION OF HEAVY CLOUD
Event No
Distance LEL (M) Distance UEL (M)
DW
CW
DW CW
1. 42 78.7 10 31.3
CONSEQUENCE ANALYSIS
Page 13
Risk Analysis For BPCL LPG Bottling Plant Durgapur, West Bengal
SCENARIO - 10
HEAVY CLOUD DISPERSION – 100 MM LIQUID LINE RUPTURE (100%) TO CAROUSAL
ASSUMPTION
1. AMBIENT TEMPERATURE : 12 (0C)
2. PIPE DIA : 100MM
3. FLOW RATE : 8.9 (Kg/Sec)
4. RELEASE TIME : 1800 SEC
5. PUMPING PRESSURE : @ 55 kl/hr at 14 Kg/CM2
6. RELATIVE HUMIDITY : 64%
DISTANCES FOR DISPERSION OF HEAVY CLOUD
Event No
Distance LEL (M) Distance UEL (M)
DW
CW
DW CW
1. 12 9.8 2 4.8
CONSEQUENCE ANALYSIS
Page 14
Risk Analysis For BPCL LPG Bottling Plant Durgapur, West Bengal
SCENARIO -11
HEAVY CLOUD DISPERSION – 100 MM VAPOUR LINE RUPTURE (25% ) FROM BULLET TRUCK
ASSUMPTION 1. AMBIENT TEMPERATURE : 12 (0C)
2. PIPE DIA : 100MM
3. FLOW RATE : 76.4 (Kg/Sec)
4. RELEASE TIME : 1800 SEC
5. PUMPING PRESSURE : 12 Kg/CM2
6. RELATIVE HUMIDITY : 70 %
DISTANCES FOR DISPERSION OF HEAVY CLOUD
Event No
Distance LEL (M) Distance UEL (M)
DW
CW
DW CW
1. 32 38.4 6 13.1
CONSEQUENCE ANALYSIS
Page 15
Risk Analysis For BPCL LPG Bottling Plant Durgapur, West Bengal
SCENARIO -12
HEAVY CLOUD DISPERSION – 100 MM LIQUID LINE RUPTURE (25% ) TO CAROUSAL
ASSUMPTION
1. AMBIENT TEMPERATURE : 12 (0C)
2. PIPE DIA : 100 MM
3. FLOW RATE : 2.2 (Kg/Sec)
4. RELEASE TIME : 1800 SEC
5. PUMPING PRESSURE : @ 55 kl/hr at 14 Kg/CM2
6. RELATIVE HUMIDITY : 70%
DISTANCES FOR DISPERSION OF HEAVY CLOUD
Event No
Distance LEL (M) Distance UEL (M)
DW CW
DW CW
1. 4 3.01 1 1.95
CONSEQUENCE ANALYSIS
Page 16
Risk Analysis For BPCL LPG Bottling Plant Durgapur, West Bengal
SCENARIO -13
HEAVY CLOUD DISPERSION –100 MM LIQUID LINE RUPTURE (100% ) FROM BULLET TRUCK TO PUMP
ASSUMPTION 1. AMBIENT TEMPERATURE : 12 (0C)
2. PIPE DIA : 100 MM
3. FLOW RATE : 260.2 (Kg/Sec)
4. RELEASE TIME : 1800 SEC
5. PUMPING PRESSURE : 12 Kg/CM2
6. RELATIVE HUMIDITY : 70 %
DISTANCES FOR DISPERSION OF HEAVY CLOUD
Event No
Distance LEL (M) Distance UEL (M)
DW
CW
DW CW
1. 10 8.7 1.8 4.4
CONSEQUENCE ANALYSIS
Page 17
Risk Analysis For BPCL LPG Bottling Plant Durgapur, West Bengal
SCENARIO -14
HEAVY CLOUD DISPERSION – 100 MM VAPOUR LINE RUPTURE (100%) FROM BULLET TRUCK
ASSUMPTION 1. AMBIENT TEMPERATURE : 12 (0C)
2. PIPELINE DIA : 100mm
3. FLOW RATE : 14.6 (Kg/Sec)
4. RELEASE TIME : 1800 SEC
5. PUMPING PRESSURE : 12 Kg/CM2
6. RELATIVE HUMIDITY : 70%
DISTANCES FOR DISPERSION OF HEAVY CLOUD
Event No
Distance LEL (M) Distance UEL (M)
DW CW
DW CW
1. 44 21.5 10 8.3
CONSEQUENCE ANALYSIS
Page 18
Risk Analysis For BPCL LPG Bottling Plant Durgapur, West Bengal
SCENARIO -15
HEAVY CLOUD DISPERSION – 100 MM CAROUSAL RETURN LINE (LIQUID)
ASSUMPTION 1. AMBIENT TEMPERATURE : 12 (0C)
2. PIPELINE DIA : 100mm
3. FLOW RATE : 8.9 (Kg/Sec)
4. RELEASE TIME : 1800 SEC
5. PUMPING PRESSURE : 8 Kg/CM2
6. COMPRESSION : 93 CFM
6. RELATIVE HUMIDITY : 70%
DISTANCES FOR DISPERSION OF HEAVY CLOUD
Event No
Distance LEL (M) Distance UEL (M)
DW CW
DW CW
1. 14.7 11.9 2.4 5.1
CONSEQUENCE ANALYSIS
Page 19
Risk Analysis For BPCL LPG Bottling Plant Durgapur, West Bengal
SCENARIO -16
HEAVY CLOUD DISPERSION – 50 MM CAROUSAL RETURN LINE (VAPOUR)
ASSUMPTION 1. AMBIENT TEMPERATURE : 12 (0C)
2. PIPELINE DIA : 50mm
3. FLOW RATE : 6.4 (Kg/Sec)
4. RELEASE TIME : 1800 SEC
5. PUMPING PRESSURE : 8 Kg/CM2
6. COMPRESSION : 93 CFM
6. RELATIVE HUMIDITY : 70%
DISTANCES FOR DISPERSION OF HEAVY CLOUD
Event No
Distance LEL (M) Distance UEL (M)
DW CW
DW CW
1. 26 11.3 6 4.4
CONSEQUENCE ANALYSIS
Page 20
Risk Analysis For BPCL LPG Bottling Plant Durgapur, West Bengal
SCENARIO -17
HEAVY CLOUD DISPERSION – 50 MM UNLOADING ARM RUPTURE (LIQUID)
ASSUMPTION 1. AMBIENT TEMPERATURE : 12 (0C)
2. PIPELINE DIA : 50mm
3. FLOW RATE : 8.9 (Kg/Sec)
4. RELEASE TIME : 1800 SEC
5. PUMPING PRESSURE : 8 Kg/CM2
6. COMPRESSION : 93 CFM
6. RELATIVE HUMIDITY : 70%
DISTANCES FOR DISPERSION OF HEAVY CLOUD
Event No
Distance LEL (M) Distance UEL (M)
DW CW
DW CW
1. 12 9.8 2 4.8
CONSEQUENCE ANALYSIS
Page 21
Risk Analysis For BPCL LPG Bottling Plant Durgapur, West Bengal
SCENARIO -18
VAPOUR CLOUD EXPLOSION -150 MM LIQUIDLINE RUPTURE FROM BULLET TRUCK ( 100% )
ASSUMPTION 1. AMBIENT TEMPERATURE : 12 (0C)
2. PIPE DIA : 150mm
3. FLOW RATE : 380.4 (Kg/Sec)
4. PUMPING PRESSURE : 12 Kg/CM2
5. WIND VELOCITY & STABILITY : 2/F
6. SOURCE STREMGTH FOR DISPERSION : 380.4 Kg/S
7 VAPOUR CLOUD RADIUS : 78.7 M
8 VAPOUR CLOUD HEIGHT : 15.4 M
9 AMOUNT IN EXPLOSIVE LIMITS : 5700 Kg
10 LEL DISTANCE : 42 M
11. RELATIVE HUMIDITY : 70%
DAMAGE DISTANCES FOR VAPOUR CLOUD EXPLOSION
SL.NO THERMAL RADIATION DISTANCE (M)
1 0.3 bar 151.1
2 0.1 bar 442.2
3 0.03 bar 755.5
CONSEQUENCE ANALYSIS
Page 22
Risk Analysis For BPCL LPG Bottling Plant Durgapur, West Bengal
SCENARIO -19
VAPOUR CLOUD EXPLOSION -100 MM LIQUID LINE TO CAROUSAL (100%)
ASSUMPTION 1. AMBIENT TEMPERATURE : 12 (0C)
2. PIPE DIA : 100MM
3. FLOW RATE : 8.9 (Kg/Sec)
4. PUMPING PRESSURE : 14 Kg/CM2
5. WIND VELOCITY & STABILITY : 2/F
6. SOURCE STREMGTH FOR DISPERSION : 8.9 Kg/S
7 VAPOUR CLOUD RADIUS : 9.8 M
8 VAPOUR CLOUD HEIGHT : 2.7 M
9 AMOUNT IN EXPLOSIVE LIMITS : 44.5 Kg
10 LEL DISTANCE : 12 M
11. RELATIVE HUMIDITY : 70%
DAMAGE DISTANCES FOR VAPOUR CLOUD EXPLOSION
SL.NO THERMAL RADIATION DISTANCE (M)
1 0.3 bar Explosion unlikely Qty low
2 0.1 bar Explosion unlikely Qty low
3 0.03 bar Explosion unlikely Qty low
CONSEQUENCE ANALYSIS
Page 23
Risk Analysis For BPCL LPG Bottling Plant Durgapur, West Bengal
SCENARIO - 20
VAPOUR CLOUD EXPLOSION -150 MM LIQUIDLINE RUPTURE FROM BULLET TRUCK ( 25% )
ASSUMPTION
1. AMBIENT TEMPERATURE : 12 (0C)
2. PIPE DIA : 150MM
3. FLOW RATE : 76.4 (Kg/Sec)
4. PUMPING PRESSURE : 12 Kg/CM2
5. WIND VELOCITY & STABILITY : 2/F
6. SOURCE STREMGTH FOR DISPERSION : 76.4 Kg/S
7 VAPOUR CLOUD RADIUS : 38.4 M
8 VAPOUR CLOUD HEIGHT : 6.5 M
9 AMOUNT IN EXPLOSIVE LIMITS : 912 Kg
10 LEL DISTANCE : 32 M
11. RELATIVE HUMIDITY : 70%
DAMAGE DISTANCES FOR VAPOUR CLOUD EXPLOSION
SL.NO THERMAL RADIATION DISTANCE (M)
1 0.3 bar 82.1
2 0.1 bar 164.3
3 0.03 bar 410.7
CONSEQUENCE ANALYSIS
Page 24
Risk Analysis For BPCL LPG Bottling Plant Durgapur, West Bengal
SCENARIO -21
VAPOUR CLOUD EXPLOSION -100 mm LIQUID LINE RUPTURE (25%) TO CAROUSAL
ASSUMPTION
1. AMBIENT TEMPERATURE : 12 (0C)
2. PIPE DIA : 100mm
3. FLOW RATE : 2.2 (Kg/Sec)
4. WIND VELOCITY & STABILITY : 1.3/F
5. SOURCE STREMGTH FOR DISPERSION : 2.2 Kg/S
6 VAPOUR CLOUD RADIUS : 3.01 M
7 VAPOUR CLOUD HEIGHT : 1.9 M
8 AMOUNT IN EXPLOSIVE LIMITS : 4.4 Kg
9 LEL DISTANCE : 4 M
10. RELATIVE HUMIDITY : 70%
DAMAGE DISTANCES FOR VAPOUR CLOUD EXPLOSION
SL.NO THERMAL RADIATION DISTANCE (M)
1 0.3 bar Explosion unlikely Qty low
2 0.1 bar Explosion unlikely Qty low
3 0.03 bar Explosion unlikely Qty low
CONSEQUENCE ANALYSIS
Page 25
Risk Analysis For BPCL LPG Bottling Plant Durgapur, West Bengal
SCENARIO -22
VAPOUR CLOUD EXPLOSION -100 MM LIQUID LINE RUPTURE (100%) FROM BULLET SUCTION
ASSUMPTION
1. AMBIENT TEMPERATURE : 12 (0C)
2. PIPE DIA : 100mm
3. FLOW RATE : 260.2 (Kg/Sec)
4. WIND VELOCITY & STABILITY : 2/F
5. SOURCE STREMGTH FOR DISPERSION : 260.2 Kg/S
6 VAPOUR CLOUD RADIUS : 58.4 M
7 VAPOUR CLOUD HEIGHT : 9.5 M
8 AMOUNT IN EXPLOSIVE LIMITS : 3120 Kg
9 LEL DISTANCE : 44 M
10. RELATIVE HUMIDITY : 70 %
DAMAGE DISTANCES FOR VAPOUR CLOUD EXPLOSION
SL.NO THERMAL RADIATION DISTANCE (M)
1 0.3 bar 82.5
2 0.1 bar 165.3
3 0.03 bar 408.5
CONSEQUENCE ANALYSIS
Page 26
Risk Analysis For BPCL LPG Bottling Plant Durgapur, West Bengal
SCENARIO -23
VAPOUR CLOUD EXPLOSION -100 MM CAROUSAL RETURN LINE (LIQUID)
1. AMBIENT TEMPERATURE : 12 (0C)
2. PIPE DIA : 100 mm
3. FLOW RATE : 8.9 (Kg/Sec)
4. WIND VELOCITY & STABILITY : 2/F
5. SOURCE STREMGTH FOR DISPERSION : 8.9 Kg/S
6 VAPOUR CLOUD RADIUS : 9.8 M
7 VAPOUR CLOUD HEIGHT : 2.7 M
8 AMOUNT IN EXPLOSIVE LIMITS : 44.5 Kg
9 LEL DISTANCE : 12 M
10. RELATIVE HUMIDITY : 70 %
DAMAGE DISTANCES FOR VAPOUR CLOUD EXPLOSION
SL.NO THERMAL RADIATION DISTANCE (M)
1 0.3 bar Explosion unlikely Qty low
2 0.1 bar Explosion unlikely Qty low
3 0.03 bar Explosion unlikely Qty low
CONSEQUENCE ANALYSIS
Page 27
Risk Analysis For BPCL LPG Bottling Plant Durgapur, West Bengal
SCENARIO -24
JET FIRE -150MM LIQUID LINE RUPTURE FROM BULLET TRUCK (100%)
ASSUMPTION 1. AMBIENT TEMPERATURE : 37.4 (0C)
2. PIPELINE DIA : 150 MM
3. FLOW RATE : 380.4 (Kg/Sec)
4. PUMPING PRESSURE : 12 Kg/CM2
5 THERMAL RADIATION INSIDE JET : 154.5 KW/M2
6. LENGTH : 205.2 M
7 WIDTH : 17.7 M
8. RELATIVE HUMIDITY : 44%
DAMAGE DISTANCES FOR JET FIRE
SL.NO THERMAL RADIATION DISTANCE (M)
1
1st Degree Burn ( 4KW/M2)
DW 238.0
CW 97.8
2
50% LETHALITY ( 12.5KW/M2) DW 22.2
CW 35.7
3
100% LETHALITY ( 37.5KW/M2) DW 209.3
CW 15.1
CONSEQUENCE ANALYSIS
Page 28
Risk Analysis For BPCL LPG Bottling Plant Durgapur, West Bengal
SCENARIO -25
JET FIRE -100 MM LIQUID LINE RUPTURE TO CAROUSAL
ASSUMPTION 1. AMBIENT TEMPERATURE : 37.4 (0C)
2. PIPELINE DIA : 100 MM
3. FLOW RATE : 8.9 (Kg/Sec)
4. PUMPING PRESSURE : @ 55 kl/hr at 14 Kg/CM2
5 THERMAL RADIATION INSIDE JET : 444.9 KW/M2
6. LENGTH : 34.1 M
7 WIDTH : 2.9 M
8. RELATIVE HUMIDITY : 44%
DAMAGE DISTANCES FOR JET FIRE
SL.NO THERMAL RADIATION DISTANCE (M)
1
1st Degree Burn ( 4KW/M2)
DW 42.6
CW 26.9
2
50% LETHALITY ( 12.5KW/M2) DW 38.9
CW 14.2
3
100% LETHALITY ( 37.5KW/M2) DW 36.3
CW 5.9
CONSEQUENCE ANALYSIS
Page 29
Risk Analysis For BPCL LPG Bottling Plant Durgapur, West Bengal
SCENARIO -26
JET FIRE -100 MM VAPOUR LINE RUPTURE FROM BULLET TRUCK (100%)
ASSUMPTION 1. AMBIENT TEMPERATURE : 37.4 (0C)
2. PIPELINE DIA : 100 MM
3. FLOW RATE : 10.06 (Kg/Sec)
4. PUMPING PRESSURE : 12 Kg/CM2
5 THERMAL RADIATION INSIDE JET : 259.4 KW/M2
6. LENGTH : 36.2 M
7 WIDTH : 3.1 M
8. RELATIVE HUMIDITY : 44%
DAMAGE DISTANCES FOR JET FIRE
SL.NO THERMAL RADIATION DISTANCE (M)
1
1st Degree Burn ( 4KW/M2)
DW 44.3
CW 25.9
2
50% LETHALITY ( 12.5KW/M2) DW 37.4
CW 13.3
3
100% LETHALITY ( 37.5KW/M2) DW 38.1
CW 5.5
CONSEQUENCE ANALYSIS
Page 30
Risk Analysis For BPCL LPG Bottling Plant Durgapur, West Bengal
SCENARIO -27
JET FIRE -100 MM LIQUIDLINE RUPTURE FROM (100%) FROM BULLET
SUCTION
ASSUMPTION
1. AMBIENT TEMPERATURE : 37.4 (0C)
2. PIPELINE DIA : 100 MM
3. FLOW RATE : 260.2 (Kg/Sec)
4. PUMPING PRESSURE : 6 Kg/CM2
5 THERMAL RADIATION INSIDE JET : 184.9 KW/M2
6. LENGTH : 171.2 M
7 WIDTH : 14.8 M
8. RELATIVE HUMIDITY : 44%
DAMAGE DISTANCES FOR JET FIRE
SL.NO THERMAL RADIATION DISTANCE (M)
1
1st Degree Burn ( 4KW/M2)
DW 130.5
CW 60.4
2
50% LETHALITY ( 12.5KW/M2) DW 125.5
CW 28.4
3
100% LETHALITY ( 37.5KW/M2) DW 114.3
CW 10.8
CONSEQUENCE ANALYSIS
Page 31
Risk Analysis For BPCL LPG Bottling Plant Durgapur, West Bengal
SCENARIO -28
JET FIRE -100 MM VAPOUR RETURN HEADER UNDER COMPRESSOR
ASSUMPTION 1. AMBIENT TEMPERATURE : 37.40 (0C)
2. PIPELINE DIA : 100 MM
3. FLOW RATE : 14.6 (Kg/Sec)
4. PUMPING PRESSURE : 8 Kg/CM2
5 THERMAL RADIATION INSIDE JET : 236.0 KW/M2
6. LENGTH : 43.2 M
7 WIDTH : 3.7 M
8. RELATIVE HUMIDITY : 44%
DAMAGE DISTANCES FOR JET FIRE
SL.NO THERMAL RADIATION DISTANCE (M)
1
1st Degree Burn ( 4KW/M2)
DW 52.2
CW 29.1
2
50% LETHALITY ( 12.5KW/M2) DW 48.4
CW 14.7
3
100% LETHALITY ( 37.5KW/M2) DW 45.3
CW 5.8
CONSEQUENCE ANALYSIS
Page 32
Risk Analysis For BPCL LPG Bottling Plant Durgapur, West Bengal
SCENARIO -29
JET FIRE -100 MM CAROUSAL RETURN LINE (LIQUID)
ASSUMPTION 1. AMBIENT TEMPERATURE : 37.4 (0C)
2. PIPELINE DIA : 75 MM
3. FLOW RATE : 8.9 (Kg/Sec)
4. PUMPING PRESSURE : 8 Kg/CM2
5 THERMAL RADIATION INSIDE JET : 444.9 KW/M2
6. LENGTH : 34.1 M
7 WIDTH : 2.9 M
8. RELATIVE HUMIDITY : 44%
DAMAGE DISTANCES FOR JET FIRE
SL.NO THERMAL RADIATION DISTANCE (M)
1
1st Degree Burn ( 4KW/M2)
DW 50.8
CW 33.5
2
50% LETHALITY ( 12.5KW/M2) DW 50.5
CW 17.6
3
100% LETHALITY ( 37.5KW/M2) DW 45.6
CW 6.9
CONSEQUENCE ANALYSIS
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Risk Analysis For BPCL LPG Bottling Plant Durgapur, West Bengal
SCENARIO -30
JET FIRE -50 MM UNLOADING ARM RUPTURE (LIQUID)
ASSUMPTION 1. AMBIENT TEMPERATURE : 37.40 (0C)
2. HOSE DIA : 50 MM
3. FLOW RATE : 8.9 (Kg/Sec)
4. PUMPING PRESSURE : 8 Kg/CM2
5 THERMAL RADIATION INSIDE JET : 444.9 KW/M2
6. LENGTH : 34.1 M
7 WIDTH : 2.9 M
8. RELATIVE HUMIDITY : 44%
DAMAGE DISTANCES FOR JET FIRE
SL.NO THERMAL RADIATION DISTANCE (M)
1
1st Degree Burn ( 4KW/M2)
DW 38.7
CW 25.1
2
50% LETHALITY ( 12.5KW/M2) DW 35.2
CW 13.3
3
100% LETHALITY ( 37.5KW/M2) DW 32.9
CW 5.7
CONSEQUENCE ANALYSIS
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Risk Analysis For BPCL LPG Bottling Plant Durgapur, West Bengal
SCENARIO -31
VAPOUR CLOUD EXPLOSION -100 MM GASKET FAILURE IN LPG PUMP DISCHARGE (25%)
ASSUMPTION
1. AMBIENT TEMPERATURE : 12 (0C)
2. PIPE DIA : 100mm
3. FLOW RATE : 2.2 (Kg/Sec)
4. WIND VELOCITY & STABILITY : 2/F
5. SOURCE STREMGTH FOR DISPERSION : 2.2 Kg/S
6 VAPOUR CLOUD RADIUS : 3.01 M
7 VAPOUR CLOUD HEIGHT : 1.9 M
8 AMOUNT IN EXPLOSIVE LIMITS : 4.4 Kg
9 LEL DISTANCE : 4 M
10. RELATIVE HUMIDITY : 70 %
DAMAGE DISTANCES FOR VAPOUR CLOUD EXPLOSION
SL.NO THERMAL RADIATION DISTANCE (M)
1 0.3 bar Explosion Unlikely Qty Low
2 0.1 bar Explosion Unlikely Qty Low
3 0.03 bar Explosion Unlikely Qty Low
RECOMMENDATION
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Risk Analysis For BPCL LPG Bottling Plant at Durgapur, West Bengal
SECTION –IX
RECOMMENDATION 9.0 SUGGESTION
Handling And Storage of Liquid Petroleum Gas is a Hazardous process as the
chemical properties of L.P.G indicates that the material is explosive. Leakage
from any point and getting a source ignition may cause disaster..
Based on M.C.A analysis, different probable accident scenarios were
identified and its consequences have been identified.
Risk contours have been plotted on the layout to show the possibilities of
damage on the onsite/offsite facilities.
Fallowing Scenarios were considered
BLEVE
5 kg cylinders
14.2 kg cylinders
19 kg cylinders
35 kg cylinders
47.5 kg cylinders
18 MT bullet truck
150 MT bullet
300 MT MSV
PIPE LINE DIA :
150 mm liquid line - Tanker to Bullet
100 MM liquid line - Bullet to pump
100 mm liquid line - Pump to carousal
100 mm pipeline - Vapour Return line
100 mm pipeline - Return line from carousal
50 mm return line - Unloading Arm
50 mm line - Vapour return line from carousal
RECOMMENDATION
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Risk Analysis For BPCL LPG Bottling Plant at Durgapur, West Bengal
BLEVE
Maximum Damage from Fireball
S no.
Failure Scenarios
Source Strength
Radius of fireball
Duration of Fireball
Intensity of Radiation inside fireball
Damage distances from the center of the fireball
m
T m s kW/m2 37.5 kW/m2
12.5 kW/m2
4 kW/m2
a) 18 MT Bullet Truck- full capacity
9 62.5 8.8 191.9 115.3 195.3 318.4
b) 150 MT Bullet ( Vessel- in open pedestal)- full capacity
75 115 15.3 217 244.6 413.6 673.4
c) 300 MT MSV - Bleve
101
187.2
20.4 252.7 BLEVE is not possible
In the above cases thermal radiation zone will spread beyond the boundary and cause
off site risk. These will also cause damage to on site facilities like unloading bay etc.
RECOMMENDATION
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Risk Analysis For BPCL LPG Bottling Plant at Durgapur, West Bengal
HEAVY CLOUD DISPERSION (dispersion LEL distance considering Release Time of 1800 sec)
S no. Scenario Pipe size
Flow rate LEL (m) UEL (m)
mm (kg/s) DW CW DW CW
a)150 mm liquid line rupture (100%)
1. from bullet truck under pressure of 12Kg/ cm2
150 380.4 (rupture assumed to be
at vessel-pipe joint)
42 78.7 10 31.3
2 liquid line . to Carousal @ 55 Kl/ Hr at 14Kg/ cm2)
100 2.2 4 3.01 1 1.95
b)100 mm vapour line rupture (25%) (from Bullet truck)
100 10.06 32 38.4 6 13.1
c)100 mm liquid line ruptures to Carousal (suction @ 14Kg/ cm2)
100 8.9
12 9.8 2 4.8
d)100 mm liquid line ruptures (Bullet to Pump
100 260.2 10 8.7 1.8 4.4
e)100 mm vapour line rupture (100%) (from Bullet truck)
100 14.6 44 21.5 10 8.3
f) 100 mm Carousel return line( liquid)
100 8.9 14.7 11.9 2.4 5.1
100 mm Carousel return line( Vapour)
50 6.4 16 11.3 6 4.4
g)50 mm unloading arm rupture 50 8.9 12 9.8 2 4.8
In case a source of ignition this may cause damage to the onsite facilities Mitigative Measures:-
1. Elimination of ground level ignition source 2. Nozzle for vapour cloud dispersion is to be put into operation 3. Provision for vapour dilution system
RECOMMENDATION
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Risk Analysis For BPCL LPG Bottling Plant at Durgapur, West Bengal
VAPOUR CLOUD EXPLOSION (DELAYED IGNITION considering Release time of 1800 Sec)
Damage distances due to VCE
S no.
Scenario Pipe size
Release rate
Wind velocit
y & Stabilit
y
Source strengt
h for dispersi
on
Cloud radius/ Height
Amount in
Explosive
limits
LEL distanc
e
Damage distances (m)
mm kg/s kg/s m kg m 0.3 bar 0.1 bar 0.03 bar
a) 150 mm liquid line rupture 1. from bullet truck under pressure of 12 Kg/ cm2) (100%)
150 380.4 2/ F 380.4 78.7/15.4
5700 28 151.1 442.2 755.5
2. from bullet truck under pressure of 12 Kg/ cm2) (25%)
150 76.4 2/F 76.4 38.4/6.5 912 32 82.1 164.3 410.7
b) 100 mm liquid line rupture
1. . to Carousal @ 50 Kl/ Hr at 14 Kg/ cm2) (100%)
100 8.9 2/ F 8.9 9.8/2.7 44.5 12 Explosion unlikely Qty low
2. to Carousal @ 50 Kl/ Hr at 14 Kg/ cm2) (25%)
100 2.2 2/ F 8.92.2 3.01/1.9 4.4 4 Explosion unlikely Qty low
c) 100 mm liquid line rupture (100%) (from Bullet suction @ 6 Kg/ cm2)
100 260.2 2/ F 260.2 58.4/ 9.5 3120 44 82.5 165.3 408.5
d) 100 mm Carousel return line (liquid)
100 8.9 2/ F 8.9 9.8/2.7 44.5 12 Explosion unlikely Qty low
Effect of explosion will spread beyond the boundary wall and will cause off site risk
RECOMMENDATION
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Risk Analysis For BPCL LPG Bottling Plant at Durgapur, West Bengal
JET FIRE (If ignited)
S no.
Scenario Pipe size
Discharge rate
Thermal radiation inside jet
Length Width Damage distances (m)
mm kg/s kW/m2 m m 37.5 kW/m2
12.5 kW/m2
4 kW/m2
DW
CW
DW
CW
DW
CW
a) 150 mm liquid line rupture (100%) 1. from bullet truck under pressure of 12 Kg/ cm2
150 380.4 154.5 205.2 17.7 29.3
15.1
22.1
35.7
238 97.8
b) 100 mm liquid line rupture to carousal
100 8.9 444.9 34.1 2.9 36.3
5.9 38.9
14.2
42.6
26.9
c) 100 mm vapour line rupture (100%) (from Bullet truck @ 12 KG/ cm2)
100 10.06 259.4 36.2 3.1 38.1
5.5 37.4
13.3
44.3
25.9
d) 100 mm liquid line rupture from bullet suction
100 260.2 184.9 171.2 14.8 114.3
10.8
125.5
28.4
130.5
60.4
e) 100 mm vapour return header under compression
100 14.6 236 43.2 3.7 45.3
5.8 48.4
14.7
52.2
29.2
2. 50mm hose rupture (liquid)
50 7.2 321.5 30.8 2.6 32.9
5.7 35.2
13.3
38.7
25.1
These will cause damage to the onsite facilities Mitigative Measures:- Activation of sprinkler system for cooling down the facilities
RECOMMENDATION
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Risk Analysis For BPCL LPG Bottling Plant at Durgapur, West Bengal
VAPOUR CLOUD EXPLOSION (DELAYED IGNITION considering Release time of 1800 Sec)
RECOMMENDATION
1. Periodic cleaning of filter element to reduce probability of rupture line due to
blockage of filter.
2. Over filling of cylinder due to reverse flow from the bullet can lead to rupture
of cylinder which are disastrous. Hence NRV in between evacuation unit and
tank to recommended.
RECOMMENDATION
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Risk Analysis For BPCL LPG Bottling Plant at Durgapur, West Bengal
9.2 FIRE FIGHTING FACILITY
Details of Fire fighting arrangements within the factory and similar additional
services that can be obtained at a short notice are as under:
ITEM DESCRIPTION. Nos. Remarks Fire Water Tanks 1x2700 KL +
1 X 2700 KL
Fire Engines 3 x 616 kL/hr Fire Extinguisher -DCP Type-75 kg 04 -DCP Type-50 kg NIL -DCP Type-10 kg 65 -CO2 Type-4.5 kg 10 -CO2 Type-2 kg NIL Dry Chemical Powder (DCP) 550kg spare Foam (AFFF) NA Foam compound Trolly-250 ltrs NA Foam compound stalls (at vulnerable points) NA Water Sprinkler for MS Tank NA Sand Buckets 8 Double Headed Water Hydrants 25 Single Headed Water Hydrants 5 Water Monitors 16 Fire Hose Reels including spares 43 Fire Hose Boxes 13 Jet Nozzles including Spares 17 Foam cum water Nozzles(FB 10X) NA FB 5X Nozzle NA Fog Nozzle 4 Triple Purpose Nozzles (Diffuser) 3 Safety Shoes 27 Safety Helmets 30 Safety Belts 5 Flame Proof Torch 2 Breathing Apparatus 1 Fire Proximity suit, Boot , Helmet, Gloves 1 Water Jel Blanket 2 Electric Siren (2 Km) 1 Hand Operated Siren 6 Public Addressing System 1 First Aid Boxes 4 Stretcher 2 Wind Socks 3 Electrical Gloves 2
RECOMMENDATION
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Risk Analysis For BPCL LPG Bottling Plant at Durgapur, West Bengal
FIRE PROTECTION FACILITIES
Fire Fighting facility at LPG Bottling Plant, Durgapur has been designed
to cover all hazardous areas in the Plant. The system comprises of:
i) Fire Water Pump House
ii) Hydrant and Water Monitor Network
iii) Medium Velocity Sprinkler System (MVSS)
FIRE WATER PUMP HOUSE
A water pumping arrangement has been provided exclusively for fire fighting
purpose. This arrangement keeps all water outlets (monitors, hydrants and
deluge valves) pressurized at 7 kg/cm2 and fire pumps are designed to start
automatically on sensing any drop in pressure below desired level.
Three Nos. diesel driven (Two Working and one Standby ) of 616KL/Hr
Capacity fire water pump and Two Nos. electric driven ( 1Nos. Working
and One Standby) of 10Kl/Hr Jockey Pump have been installed.
All the pumps are centrifugal type. The first pump is preset to start when
the line pressure drops to 6.0 kg/cm2. The second pump starts at 5.5
kg/cm2 , Jockey Pump which has been provided to maintain line pressure,
starts at 7 kg/cm2 and stop at 9 kg/cm2. Other fire engines are stand by.
All the pumps are connected to ring main which is further connected to
various monitors, hydrants and deluge valves.
All diesel driven pumps are controlled by separate control panels,
automatic engine- starting is done through the panel connected to
pressure switch in delivery mains. Engine control panel gives audio visual
alarm to indicate fault in any operating area of engine.
Arrangement has been made for self priming of all the pumps because of
aboveground water tank facility.
RECOMMENDATION
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Risk Analysis For BPCL LPG Bottling Plant at Durgapur, West Bengal
The system uses compressed air for fire detection in hazardous areas,
Supply of this air is from two air compressors provided inside the F/W
pump house.
HYDRANT & WATER MONITORING NETWORK
Fire hydrant & monitors network has been designed to cover entire plant
area & T/L Parking area. The system consists of following:
Double headed Hydrant 25 Nos.
Single headed Hydrant 5 Nos
Water Monitors 16 Nos.
DELUGE VALVE / MEDIUM VELOCITY SPRINKLER SYSTEM
Total 12 nos. of deluge valves have been designed to cover the
following areas
Position No
Storage Vessels 3 1
Filled Shed 1
Filling Shed 5
PT shed 1
Tank lorry gantry 1
LPG Pump house 1
System operation in all above areas is automatic. It uses compressed air
networks for fire detection. Quartzoid bulb type detectors are fixed at fire
sensitive positions on the air network in the hazardous area. These bulbs are
heat sensitive and burst at preset temperature (79° C). Bulb breakage causes air
pressure in the network to drop very rapidly.
RECOMMENDATION
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Risk Analysis For BPCL LPG Bottling Plant at Durgapur, West Bengal
Water spray networks in these hazards are connected to mains through control
valves, automatic in operation, named deluge valves. These deluge valves
operate when the air pressure falls below 0.7 kg/cm2
SOURCE OF WATER : 2 X2700 KL = 5400 KL
Two Above Ground Tanks have been provided for fire fighting, which is located
outside the licensed area of plant.
Material Safety Data Sheet of LPG
1. Chemical Identification
Chemical Name : LPG Synonyms : Liquefied Petroleum Gas. Chemical classification : Flammable Gas - Category 1, Gases under Pressure - liquefied gas, Carcinogenicity - Category 1B, Mutagen city - Category 1B Specific Target Organ Toxcity (Single Exposure) - Category 3 Trade name : LPG U.N.No. : 1203 Formula : Mixture MAINLY Propane & Butane, Component C.A.S No. Weight Propane (C3 H8) 74-98-6 60-90% Butane (C4 H10) 106-97-8 10-30% Propane Propylene 115-07-1 1-5% Isobutene (C4 H10) 75-28-5 1-5% 1,3- Butadiene (C4 H6) 106-99-0 0-02% Shipping name : Liquified Petroleum gas. Regulated identification : LPG. Hazardous waste ID No. : NA. Hazchem No. : Class2.1
Hazardous Ingredients:-
Hazardous Approximate C.A.S. No. LD 50/LC 50 Exposures Ingredients. Concentration(%) specify species Limits. & Route.
a) Butane 50-60 106-97-8 Not available/inh 4hrs 1000 lpm.(OEL) & 658 g/m3. 1000 lpm(TLV1)
b) Ethane <5 74-84-0 Not available. 1000 lpm(TLV1) c) Propane 40-50 74-98-6 Not available 1000 lpm.
(OEL,TLV1) [ OEL= 8 hr Alberta Occupational Exposure Limit ] [ TLV = Threshold Limit Value ( 8 hrs) ] 1 As Aliphatic Hydrocarbon Gases
2. Physical & Chemical data
Physical state Liquefied Gas Boiling Range / points (-)270c Melting / freezing points (-) 170OC to (-) 187Oc Appearance & Odour Colorless, Odorless ( or may have
Mercaptan odour) Vapour Pressure(KPA) 1100 @ 200
C Vapour Density (Air-1) 1.6 - 2.0 Solubility in water Negligible Specific Gravity water 0.53 PH Not applicable. Evaporation rate Not available. Percent Volatiles, by volume 100 Odour Threshold (PPM) Range from 2500 to 5000. Coefficient of water / Oil Distribution <0.1
Initial Boiling point & range -0.50c (31.1F) at 1,013.25 hPa Relative density 0.56 at 150c
3. Fire and Explosion Hazards Data: Appearance Flammability Yes LEL by volume 1.8% to 5.3% UEL by volume 8.5% to 15% Flash Point (-)560c to (-)600c Auto ignition 4100c-5400c TDG Flammability classification Class 2.1 Sensitivity to impact Na. Sensitivity to Static discharge Yes, May ignite Means of extinction Foam, CO2, dry chemical Powder, Explosive
accumulations can build up in areas of poor ventilation.
Special Procedure Use water spray to cool fire exposed containers and disperse Gas if Leak has not ignited. If safe To do, cut off fuel and allow flame to burn out.
Hazardous Ploymerisation :
Combustible Liquid : Yes Explosive material : Yes Corrosive material : No Flammable material : Yes Oxidizer : NA Other : NA Pyrophoric material : NA Organic peroxide : NA
4. Reactivity Data
Chemical stability : Stable Condition : Not applicable Incompatibility with other material : Chlorine and other strong oxidizing agents. Reactivity : Yes Conditions : heat, strong sunlight Hazardous Reaction Product : On fire it will liberate some amount carbon monoxide, and Carbon-di-oxide.
5. Health Hazards Data
Routes of Entry : Inhalation , eye contact. Effects of Exposure symptoms : Inhalation can cause head ache, disorientation, dizziness
drossiness and possibly unconsciousness. Evidence exists that butane and propane can cause these effects at concentrations for below those require for oxygen deficiency, for example 10% LEL and above. As concentration increases, oxygen deficiency and asphyxiation may occur. Rapidly expanding gas are vaporized liquid may cause frostbite to skin and eyes.
Emergency Treatment : in case of contact with Skin flush with fresh with fresh water ,
remove containment clothing, in case of excessive inhalation move the victim to fresh air, obtain medical assistance.
Sensitization to Product : No Exposure limit of Product : 1000 lpm(OEL,TLV) Irritancy : Not available. Synergistic materials : None reported. Chronic exposure : Weakness, coughing, labored breathing, headache confusion
nausea/vomiting convulsions heart rate and pulse variations coma respiratory failure.
NFPA Hazards Health Flammability Instability Special Signals 2 4 0 none HMIS ratings Health Flammability physical hazards 1 4 2
6. Preventive measures: Personal Protective equipment : use Positive pressure self contained breathing apparatus
Or supplied air breathing apparatus when entering areas where high concentration may be presents.
a) Gloves: Insulated gloves. b) Respiratory Protection: SCBA ar SABA. c) Eye: splash goggles and face shield if SCBA or SABA not warn.
Handling and storage Precautions : Aroid contact with liquid cooled equipment, Avoid inhalation, avoid sparking condition store in a cool, dry, well ventilated area away from heat, strong sunlight and ignition source.
Keep away from fire, sparks & heated surfaces no smoking near
areas where material is stared or handled. The product should only be stored and handled in areas with intrinsically safe electrical classification.
7. Emergency and First aid measures:
Suitable Fire Extinguishing media : Foam, dry chemical powder, co2, containers which are not cooled with water spray
Extinguishing media to avoid : water Caution about specific danger in case of : Danger of violent reaction or explosion, vapors Fire and fire fighting procedures may travel considerable distances and cause
subsequent ignition. Vapors are heavier than air, may cumulate along the round in enclosed spaces – danger of explosion when burning; it emits carbon monoxide & CO2 and irritant fumes.
Fire Special procedures : Shut off leak, if safe to do so,. Keep non –involved
people away from spill site. Issue warning “ FLAMMABLE” . Eliminate all sources of ignition.
Unusual Hazards : Vapor heavier than Air it will spread along the the ground and collect in sewer. Exposure First Aid measures : Skin contact ; in freeze burn occurs, gently Bathe affected area in warm water (38-43)0C. Do not rub get medical attention Eye : Immediately flash with large amounts of Luke warm water for 15 minutes, lifting upper & lower lids at intervals. Seek medical attention If irritation persists.
Inhalation: Remove to fresh air, give oxygen, artificial respiration or CPR needed seek medical attention Ingestion : Usually no effect by this Route
Antidotes/Dosages : NA
Spills Steps to be taken : Shut off leak , if safe to do so, Keep non – Involved people away from spillage site.
Eliminate all sources of ignition. Prevent spill entering in to sewers, for Major spillage contact emergency services.
Waste disposal Method : NA