Schedule XXIX

FLAMMABLE LIQUEFIED OR COMPRESSED GASES AND HIGHLY

FLAMMABLE LIQUIDS

1. Application

Provisions of this Schedule shall apply to all factories where flammable

liquefied or compressed gases or highly flammable liquids are

manufactured, stored, handled used (sic.).

2. Definitions

For the purposes of this Schedule

(a) "bulk storage " means bullet or Horton sphere or mounded vessel or

portable cylinders used for storage of flammable liquefied or

compressed gases or highly flammable liquids, which are having

cumulative water storage capacity exceeding one thousand liters;

(b) "bullet" means a horizontal cylindrical pressure vessel with

hemispherical or dished ends used for storage of flammable liquefied or

compressed gas;

(c) “explosive mixture” means a mixture of combustion agent (oxidizing

substance in gaseous, liquid or solid state) and a fuel (oxidisable

substance in gaseous, liquid or solid state) in such proportions that it

could give rise to a very rapid and violent oxidation reaction, liberating

more kinetic energy than is dissipated through conduction and

convection, ultimately causing practical effect of explosion ;

(d) "fire proof " means a passive means of protection of a structure or

equipment or vessel from exposure to direct fire or flame impingement

or prolonged exposure to high intensity radiant thermal flux, by the

application of a coating of certain heat-resistant substance or mixture

of a specified rating ;

(e) "fire safe " means a provision of dual seating to control leakage to

acceptable level, even after damage, due to fire, as applied to valves

(f) "flammable compressed gas " means flammable compressed gas as

defined in rule 2 of the Static and Mobile Pressure Vessels (Unfired)

Rules, 1981 framed under the Explosives Act, 1884 (Central Act IV of

1884) ;

(g) "flammable liquefied gas " means a flammable gas kept in liquefied

state by the application of pressure at normal ambient temperature,

13% (thirteen percentage) or less of which by volume with air forms a

flammable mixture or which has a flammable range with air of atleast

12% (twelve percentage) points regardless of the lower flammable

limits;

(h) "gas free " means a condition when the concentration of a flammable

gas in an equipment or a vessel is well below the threshold limits

(lower explosive limit), so, that it is safe for a man to enter into the

equipment or vessel or to conduct "hot work " there, as the case may

be ;

(i) "highly flammable liquid " means any liquid including its solution,

emulsion or suspension which when tested in a manner specified by

sections 14 and 15 of the Petroleum Act, 1934 (Central Act XXX of

1934) gives off flammable vapors at a temperature less than 32

degrees Centigrade:

(j) "Horton sphere" means a spherical Pressure Vessel, supported

vertically and is used for the storage of flammable liquefied or

compressed gas;

(k) "hot work" means an activity which may produce enough heat or spark

to ignite a flammable or explosive mixture;

(l) "Mounded vessel" means a pressure vessel for the storage of

flammable liquefied or compressed as, which is placed above ground

and is completely covered by a mound of earth or similar inert material

except for nozzles, manhole covers, inspection covers fitted on the top

of the vessel ;

(m) "purging" means an act of replacing the atmosphere inside a vessel

or a container by an inert gas in such a manner as to prevent the

formation of an explosive mixture.

(n) "purging into service" means the replacement of air in a closed system

by an inert gas and then replacement of the inert gas by the flammable

gas, vapour or liquid;

(o) "purging out of service" means the replacement of normal flammable

content of a closed system by an inert gas and then replacement of the

inert gas by air to such an extent that it is gas free and safe for any

person to work ;

(p) "remote operated emergency valve" means a shut-off valve capable of

remote operation which closes automatically on loss of the actuating

power or fire engulfment and which is fire-safe.

3. Storage

Every highly flammable liquid, flammable liquefied or compressed gas used

in every factory shall be stored in bulk in suitable fixed storage tank made

of adequate fire-resistant construction and located in a safe position under

the ground or in the open.

4. Location and spacing

Before selecting the location of any storage vessel, risk analysis study shall

be carried out. Based on the risk analysis study, every storage vessel shall

be located in the manner specified below:

(a) the location shall not interfere with the movement of vehicles. The Risk

Contour shall not intercept the public places such as assembly points,

canteen, rest sheds and similar other locations;

(b) before locating any storage vessel, the soil-condition shall be assessed

for the suitability of the super structure ;

(c) the storage vessel shall be sited above ground in open air and well-

ventilated place ;

(d) mounded vessels shall be so located that the man holes and pressure

relief valves are in a well-ventilated position;

(e) the minimum safety distance between the storage vessels and from

buildings, boundary or fixed ignition source shall be in accordance with

the Static and Mobile Pressure Vessels (Unfired) Rules, 1981, as

amended from time to time ;

(f) the storage vessels shall not be installed one above the other;

(g) the bullets shall be so located that their longitudinal axes do not points

towards other vessels, vital process equipment, control rooms, loading

stations, nearby buildings or storage tanks containing hazardous

materials;

(h) weeds, long grass, deciduous shrubs and trees and any combustible

materials shall be removed from the storage vessel area within the

licensed premises;

(i) the storage vessels shall not be located within the blinded enclosure of

any heat source or other flammable liquids, gases or oxidizers ;

(j) the storage vessels, pumping equipment, loading and unloading

facilities and vaporizers shall be located in an exclusive fenced

compound of atleast 2 meters high along the perimeter of the safety

zone'; such fenced compound shall have atleast two gates for the safe

exit of persons and vehicles in case, of any emergency ;

(k) the number of storage vessels in one group shall not exceed six;

(l) storage vessels within a group shall be so located that their longitudinal

axes are parallel to each other;

(m) spheres and bullets shall not be grouped together and shall be

provided with separate piping manifold, so as to avoid over filling of a

vessel due to gravitation from the other;

(n) the top surface of the storage vessels installed in a group shall be on

the same plane so that the pressure safety valve blow-out from them

do not affect the other;

(o) the flooring of the bullets or spheres shall be sloped in such a way that

the spilled liquid or gas from any vessel shall not pass through any

other vessel;

(p) the storage vessels shall not be located in such a way that the high

tension electrical cables shall not pass through or near the licensed

premises;

(q) storage vessels shall not be located in places which are susceptible to

flooding;

(r) the grade for the storage vessels shall be elevated slightly above the

surrounding terrain in order to ensure complete drainage of water from

beneath the bottom of the vessels; and

(s) every container, vessel or tank used for storing highly flammable liquid

or flammable liquefied or compressed gas shall be clearly and in bold

letters marked Danger — Highly Flammable Liquid " or - Danger —

Flammable liquefied or Compressed Gas ", as the case may be.

5. Design of storage vessels

(1) General: Each static vessel for the storage of flammable liquefied or

compressed gas shall be provided with the following finings and

instruments which are suitable for use at pressures not less than the

design pressure of the vessel and for the temperatures appropriate to the

worst operating conditions namely:

(a) At least two pressure safety valves connected independently to the

vapour space;

(b) Two independent liquid level indicators;

(c) A high level switch with alarm;

(d) A pressure gauge, connected to the vapour space; and

(e) a temperature gauge for measuring the temperature of the contents of

the vessel.

(2) Vessel connections: In every flammable liquefied or compressed gas

storage vessel

(i) all the connections to the vessel shall be designed and fitted in

accordance with the Design Code of Indian Standard-2825 or equivalent

duly approved by the Chief Controller of Explosives;

(ii) not more than one nozzle shall be provided at its bottom for inlet and

outlet purpose, apart from the drainage pipe

(iii) the nozzle shall be a full-welded pipe and shall extend to a minimum

distance of 3 (three) meters from the shadow of the vessel. A

combination of manual and remote operated shut-down valve shall be

provided on this bottom nozzle at a distance of atleast 3 (three) meter

beyond the shadow of the vessel. The nozzle shall have a slope of 1.5

degree ;

(iv) the nozzle shall be stress-relieved along with the vessel;

(v) (sic) there shall not be any flange, instrument tapping or manhole fitted

on this nozzle up to the combination of manual and remote operated

valve ; and

(vi) An excess flow valve shall be provided for the nozzle on the body of the

vessel.

(3) Pressure Safety Valve: In every storage vessel

(i) the pressure safety valves provided shall be of spring-loaded type

(weight-loaded safety valves shall not be used). Each of the pressure

safety valves shall have 100% (hundred percent.) relieving capacity;

(ii) the pressure safety valves shall be set to discharge at a pressure not

more than 110 (one hundred and ten) percent. of the design pressure

of the vessel and shall have a total relieving capacity adequate for

limiting the pressure build-up in the vessel not more than 120 (one

hundred and twenty) per cent. of the design pressure;

(iii) the discharge of the pressure safety valves shall be connected to flare

system. If available, In case the flare system is not available, the

discharge from the pressure safety valve shall be vented vertically

upwards to atmosphere at a minimum elevation of 3 meter above the

top of the vessel for effective dispersion of the discharge. A loose-fitting

rain cap with a non-sparking chain attached to the vent pipe shall be

fitted on top of the pressure safety valve;

(iv) an isolation valve shall be provided in between each pressure safety

valve and the vessel. The arrangement of such isolation valve shall be

so designed as to afford full required capacity flow through atleast one

of the pressure safety valves ; and

(v) each pressure safety valve shall be visibly marked with the "set

pressure" in Kg/Sq.Cm. (gauge) at which it will discharge, with its

actual rate of discharge in cubic meter per minute of the gas at a

pressure of 120 (one hundred and twenty) percent of the design

pressure of the vessel.

(4) Emergency shut-off valve: In every storage vessel

(i) all liquid and vapour connections, except those for pressure safety

valves and the drainage connections of diameter less than 25 (twenty five)

mm., shall have an emergency shut-off valve, such as an excess flow

check valve or a remote operated valve:

Provided that the emergency shut-off valve is not required in cases where

the connection to a vessel is not greater than three centimeter in diameter

for liquid and eight centimeter in diameter for vapour ;

(ii) where the emergency shut-off valve provided is of 'excess flow check

valve' type, its closing rate of flow shall be below the rate which is likely to

result due to a fracture of the line which it is protecting, calculated under

the worst conditions. Excess flow check valve shall have a flow capacity

sufficiently above the normal flow requirements to prevent valve chatter.

(5) Bottom water draw-off or drain valve-In every storage vessel

(i) there shall be provided two drain valves at the bottom of the vessel

between the remote operated valve and the first isolation valve. The

length of the pipeline between the two drain valves shall be atleast 0.5

meter to minimize the risk of simultaneous obstruction of both valves

due to freezing of any water present in the liquefied gas. The drain

connections shall be not more than 50 (fifty) millimeter in diameter;

(ii) the first drain valve from the vessel shall be of gate type (throttle type),

while the second drain valve shall be of quick shut-off type ;

(iii) the material of construction for the drain pipeline and the related

connections shall be suitable for cryogenic application.

(6) Sampling valve: In every storage vessel, two valves with suitable distance-

pipe of not less than 0.5 meter in length between them shall be fitted at its

bottom between the remote operated valve and the first isolation valve for

sampling purpose. (The provision of a distance-pipe is for the purpose of

avoiding icing problem in the up stream valve)

(7) Liquid level gauging device: In every storage vessel, out of two level

indicators provided, one shall be of "float" type and the other shall be of

"differential pressure" type in case of Horton Spheres. Magnetic float type

gauge shall be used for bullets in the place of "differential pressure" type

"High Level" alarm shall be set on the level indicators to operate at not

more than 85% (eighty five percent.) of the volumetric capacity of the

vessel. An audio-visual indication as regards the high level alarm shall be

provided at the normal place of operator's seat.

(8) Pressure gauge: In every storage vessel, there shall be provided atleast

one pressure gauge, duly calibrated and having a dial range not less than

1.5 times the design pressure, easily visible and designed to show the

correct internal pressure at all times. It shall be provided in the vapour

space at the top. A suitable stop valve shall be provided in between the

vessel and the pressure gauge.

(9) Gas sensors: In every storage vessel for flammable liquefied or

compressed gas, gas sensors with alarm shall be provided at vulnerable

areas and in the event of gas leakage, such sensor shall trip the

compressor or pump if in operation.

(10) Bonding: Electrical continuity shall be maintained between the flanges by

means of bonding in every storage vessel and its pipe lines.

(11) Pop off valves: “Pop off" valves shall be provided in between isolation

valves on the pipelines carrying flammable liquefied or compressed gases.

(12) Capacity of vaporizer: The vaporizer, connected to the flammable

liquefied gas storage vessels shall have adequate capacity to meet the

required flow rate of flammable liquefied gas in the process.

6. Prevention of ignition

In every location where highly flammable liquid or flammable

liquefied or compressed gas is stored, conveyed, handled or used or where

there is danger of fire or explosion from accumulation of highly flammable

liquid or liquefied compressed gas in air, all practicable measures shall be

taken to exclude the sources of ignition. Such precautions shall include the

following:

(a) all electrical apparatus shall either be excluded from the area of risk or

they shall be of such construction and so installed and maintained as

to prevent the danger of their being a source of ignition;

(b) effective measures shall be adopted for prevention of accumulation of

static charges to a dangerous extent;

(c) no person shall wear or be allowed to wear any footwear having iron

or steel nails or any other exposed ferrous materials which is likely to

cause sparks by friction;

(d) smoking, lighting or carrying of matches, lighters or smoking

materials shall be prohibited;

(e) transmission bolts with iron fasteners shall not be used; and

(f) all other precautions, as are reasonably practicable, shall be taken to

prevent initiation of ignition from all other possible sources such as

open flames, frictional sparks, over heated surfaces of machinery or

plant, chemical or physical-chemical reaction and radiant heat.

7. Enclosed system for conveying highly flammable liquids:

Wherever it is reasonably practicable, highly flammable liquids shall be

conveyed within a factory in totally enclosed system consisting of pipe

lines, pumps and similar appliances from the storage tank or vessel to the

point of use. Such enclosed system shall be so designed, installed,

operated and maintained as to avoid leakage or the risk of spilling.

8. Prohibition of smoking:

No person shall smoke in any place where a highly flammable liquid or

flammable liquefied or compressed gas is present in circumstances that

smoking would give rise to a risk of fire. The occupier shall take all

practicable measures to ensure compliance with this requirement including

display of a bold notices indicating prohibition of smoking at every place

where this requirement applies.

9. Fire protection:

In every factory

(1) no vehicular traffic shall be permitted within the risk area of lower

flammable limit of the highly flammable liquid or flammable liquefied or

compressed gas stored. When required, vehicles filled with approved

spark arrestors shall only be allowed with valid vehicle entry permit.

(2) all the vessels used for bulk storage or handling of highly flammable

liquid or flammable liquefied or compressed gases shall be protected

against the hazards of fire as follows:

(a)medium velocity water spray system shall be provided for all above

ground storage vessels, cylinder storage or filling or repair sheds,

pump houses, bulk lorry and tank wagon gantries;

(b) detection of fire for automatic actuation of medium velocity water

sprinkler system shall be provided at all critical locations such as bulk

storage, tank truck or tank wagon gantry, pump or compressor

house and vapourisers ;

(c) medium velocity water sprinkler system shall be based on heat and

other detection.

(d) Quartzoid Bulb protection designed to blow at 79 (seventy nine)

degree centrigrade (maximum) shall be provided in open areas or in

the sheds ;

(e) Medium velocity water sprinkler system shall function in such away

that the actuation of fire detectors shall initiate the following:

(i) opening of deluge valve;

(ii) audio-visual alarm at the fire pump house or control panel;

(iii) fire siren; and

(iv) the diesel pump will get started based on the "Set pressure" to

supplement or to maintain the fire water pressure in the ring

main; and

(f) The medium velocity water sprinkler system shall have a minimum

spray density of ten liters per minute per square meter in the case of

flammable liquefied or compressed gas and in the case of highly

flammable liquid it shall have minimum spray density of 3 (three)

liters per minute per square meter for the single largest risk area.

For the purpose of calculation of a single risk area, the following shall

be taken into account:

(i) in case of bulk storage, adjoining vessels within the distance of R

+ 30 (thirty) meter, where R is the radius of the vessel and 30

(thirty) meter shall be measured from the periphery of the vessel

(ii) in case of tank lorry gantry, a maximum of 8 (eight) bays shall be

taken as a single risk area ; and

(iii) in case of tank wagon gantry, a minimum of one gantry (600 (six

hundred) Metric Tonnes) shall be taken as a single risk area

(3) (a). a fire water ring main shall be provided all around the locations of

storage and handling of flammable liquefied or compressed gases with

hydrants or monitors spaced at 30 (thirty) meter centre to centre. Fire

hydrants and monitors shall be installed outside the licensed premises;

(b). the fire water pressure system shall be designed for a Minimum

residual pressure of 7(seven) Kgf/Sq.Cm. (gauge) at the remotest place of

application in the plant ;

(c). fire hydrant network shall be provided in closed loops to ensure multi-

directional flow in the system. Isolation valves shall be provided to enable

isolation of any section of the network without affecting the flow in the

rest; and

(d). the fire water system in the plant shall be designed to meet the

highest fire-water flow requirement of medium velocity water sprinkler for

a single largest risk area at a time plus 288 (two hundred and eighty eight)

meter/hour for operating 2 (two) numbers fire water monitor or

supplementary hose requirements.

(4)(a). water for the hydrant service shall be stored in any easily accessible

surface of underground concrete reservoir or above ground tank of steel or

concrete;

(b). the effective fire water storage capacity available for fire-fighting

shall be for four hours; and

(c). storage tank or reservoir for fire water shall be in two interconnected

compartments to facilitate cleaning and repair.

(5) Portable fire extinguishers as approved by Bureau of Indian Standards

shall be located at convenient places as indicated in the Table below :—

THE TABLE

AREA PORTABLE FIRE EXTINGUISHER

(1) (2)

1. Flammable liquefied gas or 2 Numbers 10Kg.DCP

storage vessels (each)

2.Tank wagon loading or 1 Number 10 Kg. DCP.

unloading gantries extinguisher for every 15/20

meters of gantry

3.Tank truck loading or 1 Number 10Kg.DCP, fire

unloading gantries extinguisher in each Bay and 1

Number 50 Kg. Mobile DCP

unit/gantry

The dry chemical powder used in the extinguishers shall be

potassium or Urea based or Sodium Bicarbonate as per IS: 4308. The

expellant gas ie., N2/CO2 should be of good quality.

10. Loading and unloading facilities for flammable liquefied or compressed gas:

(1) Loading: In every factory, where the loading of flammable liquefied or

compressed gas is carried on, the loading station shall consist of the

following:

(a) A filling line with an isolation valve and check valve;

(b) a vapour return line with a check valve and an isolation valve to be

connected back to the storage vessel from which the loading pump is

drawing flammable liquefied gas ;

(c) suitable loading arm or flexible hoses shall be provided at the end of

filling line and vapour return line for connecting to the tank truck

vessels or tank wagons ; and

(d) Suitable thermal pressure relief valve(s) shall be provided between the

shut-off valves to protect against excessive pressure which may

develop due to thermal expansion of the trapped liquid.

(2) Unloading: In every factory, where unloading of flammable liquefied or

compressed gas is carried on, the compressor used for unloading of

flammable liquefied gases by means of a differential pressure between the

receiving and discharging vessels by withdrawing vapour from the

receiving vessel and forcing it at high pressure into the discharging vessel

shall have the following facilities:

(a) Liquid unloading check valve line with isolation valve; and

(b) Vapour line with isolation valves;

(3) Loading and unloading operations: In every factory, where the loading or

unloading of flammable liquefied or compressed gas is carried on

(a) written operating procedures for loading or unloading operation, clearly

defining the safety checks and precautions to be observed as well as

the responsibilities of the personnel involved in such operation, shall be

prepared both in English and in Telugu and shall be given to them and

also displayed at the site;

(b) flexible hoses used for transfer of flammable liquefied or compressed

gas to or from a tank truck or tank wagon shall be,

(i) designed and constructed in accordance with the Static and Mobile

Pressure Vessels (Unfired) Rules, 1981;

(ii) having a means of identification; and

(iii) periodically checked for electrical and mechanical continuity and

recorded in the register;

(c) for connecting and disconnecting hoses, only non-sparking type of tools

shall be used;

(d) the tank truck shall have the starter motor which shall be of non-

sparking or flame-proof type;

(e) the tank truck shall be positioned on a leveled ground and blocks

(checks) shall be placed at front and rear wheels in order to prevent

the risk of accidental vehicle movement;

(f) the engine of the vehicle shall be stopped and all the electrical

equipment shall be switched off, before commencing the loading or

unloading operation;

(g) before commencing the loading or unloading operation, static charge

shall be effectively discharged by bonding and earthing of the storage

vessels and the road tankers or wagons;

(h) the road tanker or wagon shall be electrically bonded at, specified point

to the fixed grounding system;

(i) an authorised person shall supervise the transfer operation and

respond immediately in the event of an emergency;

(j) during loading operation, the pressure within the receiving tank truck

vessel shall be observed to ensure that it does not approach the" start-

to-discharge" pressure of the relief valve. Filling rate shall be regulated

as required;

(k) the receiving vessel which is having an internal pressure of less than 1

(one) Kg/Sq.Cm (g) shall not be permitted to be filled, such vessel shall

be checked for Oxygen content or explosive mixture and purged, if

necessary ;

(l) filling or transfer operation shall be done only during day time;

(m) filling or transfer operation shall be stopped immediately in the event

of —

(a) uncontrolled leakage occurring;

(b) a fire occurring in the vicinity;

(c) lightning and thunder-storm;

(n) the "Safe Operating Procedure" for unloading shall be displayed

conspicuously in English and Telugu near the unloading area.

11. Maintenance and Inspection

In every factory where highly flammable liquid or flammable liquefied

or compressed gas is stored in bulk.

(1) the storage vessels and the safety fittings and instruments shall be

tested periodically as per the requirements under various statutes as

applicable and relevant records with the particulars of such testing shall

be maintained;

(2) loading or unloading hoses shall be tested at least once in every six

months;

(3) the earth pits shall be maintained well and the earth resistance shall be

measured atleast once in every 12 (twelve) months ; and records shall

be maintained in this regard ;

(4) the foundation and supports of the storage vessels shall be checked once

in a year for differential settlement due to disturbance in the sub-soil ;

(5) the cathodic protection, if provided, shall be monitored periodically and

maintained well for its effectiveness ;

(6) the gas detection system shall be checked and calibrated periodically;

and

(7) the fire water system which includes fire water pumps, fire hydrant or

monitor, piping network and water sprinkler or deluge system shall be

checked periodically and maintained well for its fail-safe operation.

12. Training

The occupier of every factory in which highly flammable liquid or

flammable liquefied or compressed gas is stored in bulk shall ensure that

(1) the supervisory or managerial personnel are adequately trained in all

aspects of safe storage and handling of highly flammable liquid or

flammable liquefied or compressed gas as well as disaster control or

preparedness and response

(2) regular raining programmes are conducted in loading or unloading

operation, drafting procedure, commissioning and decommissioning

procedures,” hot work” permit system, fire-fighting or emergency

combat operation, health hazards etc., for

(a) regular workers;

(b) contract workers; and

(c) security staff.

(3) Full-scale emergency mockdrill, simulating leakage of flammable gas and

the consequent major fire, are conducted in the plant atleast once in every

six months in order to assess the level of preparedness and the adequacy

of combat measures. Any deviations or defects observed during such

mock- drill shall be rectified forthwith.