OISD STANDARD - 144
Second Edition, October 2005
FOR RESTRICTED
CIRCULATION ONLY
LIQUEFIED PETROLEUM GAS (LPG)
INSTALLATIONS
Prepared by
FUNCTIONAL COMMITTEE ON
LIQUEFIED PETROLEUM GAS (LPG)
OIL INDUSTRY SAFETY DIRECTORATE
GOVERNMENT OF INDIA
MINISTRY OF PETROLEUM AND NATURAL GAS
7th Floor, New Delhi House
27, Barakhamba Road
Connaught Place, New Delhi 110 001
NOTE
Oil Industry Safety Directorate (OISD) publications are prepared for use in the oil and gas industry under Ministry of Petroleum & Natural Gas. These are the property of Ministry of Petroleum & Natural Gas and shall not be reproduced or copied and loaned or exhibited to others without written consent from OISD.
Though every effort has been made to assure the accuracy and reliability of the data contained in these documents, OISD hereby disclaims any liability or responsibility for loss or damage resulting from their use.
These documents are intended to supplement rather than replace the prevailing statutory requirements.
FOREWORD
The Oil Industry in India is more than 100 years old. As such, a variety of practices have been in vogue because of collaboration/ association with different foreign companies and governments. Standardisation in design philosophies , operating and maintenance practices was hardly in existence at a national level. This, coupled with feed back from some serious accidents that occurred in the recent past in India and abroad, emphasised the need for the industry to review the existing state of art in designing, operating and maintaining oil and gas installations.
With this in view, the Ministry of Petroleum & Natural Gas in 1986 constituted a Safety Council assisted by the Oil Industry Safety Directorate (OISD) for formulating and implementing a series of self regulatory measures aimed at removing obsolescence, standardising and upgrading the existing standards to ensure safer operations. Accordingly, OISD constituted a number of functional committees comprising of experts nominated from the industry to draw up standards and guidelines on various subjects.
Liquefied Petroleum Gas (LPG) has been used extensively as domestic fuel as well as with industrial applications due to its unique properties and environmental benefits. The document on "LPG Bottling plant operations" was prepared in 1994. The present document "LPG Installations" has been prepared by the functional based on the accumulated knowledge and experience of industry members and updation of national and international codes and practices related to LPG.
This document will be reviewed periodically for improvements based on the new experiences and better understanding. Suggestions may be addressed to :
The Coordinator,
Committee on “LPG”
Oil Industry Safety Directorate,
7th floor, New Delhi House,
27, Barakhamba Road,
New Delhi – 110001
FUNCTIONAL COMMITTEE
( Second Edition - October, 2005)
NAME / ORGANISATIONLEADER
Sh. R. Krishnan / Hindustan Petroleum Corporation Ltd., MumbaiMEMBERS
Sh. A.N. Biswas / Deptt. of Explosives, NagpurSh. N. Rajkhowa,
/ Engineers India Limited, New DelhiSh. B.S. Giridhar / Indian Oil Corporation Ltd., - HQ, Mumbai
Sh. N. Dasgupta
/ Bharat Petroleum Corporation Ltd., MumbaiSh. T.Koteeswaran
/ Chennai Petroleum Corporation Ltd., ChennaiSh. B.J. Phukan
/ Numaligarh Refinery Ltd., AssamSh. P. Jaidevan
/ Indian Oil Corporation Ltd., CalicutSh. S. Ramesh / Bharat Petroleum Corporation Ltd., Noida
MEMBER COORDINATOR
Sh. S. C. Gupta / Oil Industry Safety Directorate, New DelhiFUNCTIONAL COMMITTEE MEMBERS
( First Edition – April 1994 )
NAME / ORGANISATIONLEADER
Sh. S.C. Tandon / Indian Oil Corporation Ltd., ( Ref.)MEMBERS
Sh. H.G. Bhinde / Indian Oil Corporation Ltd., ( Mkt.)Sh. A.C. Kelkar
/ Indian Oil Corporation Ltd., ( Mkt.)Sh. V. Narayana Rao / Bharat Petroleum Corporation Ltd., (Mkt.)
Sh. P. Kumaraswamy
/ Bharat Petroleum Corporation Ltd., ( Ref.)Sh. P.P. Nadkarni
/ Hindustan Petroleum Corporation Ltd., (Mkt.)Sh. S. Mathur
/ Engineers India Limited, New DelhiMEMBER COORDINATOR
Sh. S. C. Gupta / Oil Industry Safety Directorate, New DelhiCONTENTS
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SR. No. ITEM PAGE NO
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1 Introduction
2 Scope
3 Definitions
4 Statutory Rules/ Regulations
5 Installation Layout
6 Design Considerations
7 Storage & Handling of Bulk LPG
8 Bottling Operations
9 Maintenance & Inspection
10 Statutory Testing of LPG Cylinders
11 Fire Protection Facilities
12 Gas Monitoring System
13 Emergency Management Plan
14 Safety Audit
15 References
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LIQUEFIED PETROLEUM GAS (LPG)
INSTALLATIONS
1.0 INTRODUCTION
Liquefied Petroleum Gas (LPG) is a mixture of light hydrocarbons primarily C3 & C4 derived from petroleum, which is gaseous at ambient temperature and atmospheric pressure, is liquefied at ambient temperature with application of moderate pressure. LPG due to its inherent properties is susceptible to fire, explosion and other hazards. Such hazards can have an impact on the property, equipment, plant personnel and public.
Liquefied Petroleum Gas (LPG) handling, bottling and distribution throw major challenges due to its inherent properties. Major incidents i.e. fires/explosions in LPG facilities in world have underlined the need for total in depth review of design, procedures, maintenance, fire fighting and safety aspects in LPG handling.
The oil and gas industry over the years have learnt lessons from fires and explosions and have been updating and standardising design, operations, bottling and distribution of LPG.
Some of the important properties of LPG are as below :
· LPG at atmospheric pressure and temperature is a gas which is 1.5 to 2.0 times heavier than air. It is readily liquefied under moderate pressures. The density of the liquid is approximately half that of water and ranges from 0.525 to 0.580 @ 15 oC.
· The pressure inside a LPG storage vessel/ cylinder is equal to the vapour pressure corresponding to the temperature of LPG in the storage vessel. The restriction on vapour pressure is stipulated by IS-4576.
· LPG has an explosive range of 1.8% to 9.5% volume of gas in air. This is considerably narrower than other common gaseous fuels. This gives an indication of hazard of LPG vapour accumulated in low lying area in the eventuality of the leakage or spillage.
· Water, being insoluble in LPG, if present in LPG can cause rust and corrosion and freeze-up of valves, drain valves, excess-flow check valves, cylinder valves and regulators thereby affecting their functioning and at times can lead to leakage of LPG.
· LPG liquid has low viscosity of around 0.3 CS @ 45 oC and can leak when other petroleum products normally cannot, thus demanding a very high integrity in the pressurised system to avoid leakage.
· LPG even though slightly toxic, is not poisonous in vapour phase, but can, however, suffocate when in large concentrations due to the fact that it displaces oxygen. In view of this the vapour posses mild anaesthetic properties.
· LPG is colourless both in liquid and vapour phase. During leakage the vapourisation of liquid cools the atmosphere and condenses the water vapour contained in them to form a whitish fog which may make it possible to see an escape of LPG.
· The coefficient of expansion is around 0.00237 per oC. At liquid full condition any further expansion of the liquid, the container pressure will rise by approx. 14 to 15 kg./sq.cm. for each degree centigrade.
· LPG has only a very faint smell, therefore, ethyl mercaptan is normally used as stenching agent for identifying the leakage as per IS : 4576.
· The auto-ignition temperature of LPG ranges from 410 to 580 oC.
2.0 SCOPE
This standard lays down the minimum safety requirements on design, layout, storage, loading / unloading, operation, inspection & maintenance, fire protection, emergency planning and safety audit systems of LPG Installations. This standard does not cover process plants, the distribution of LPG to domestic & non-domestic consumers and pipeline operations, road / rail transportation, refrigerated and mounded storage facilities for LPG.
This standard is not applicable to bottling plants having a bulk LPG inventory not exceeding 100 MT with minimum two storage vessels and with LPG bottling a total quantity not exceeding 20 MT per shift of 8 hrs. The safety requirement for such LPG Bottling plants are covered in OISD-GDN-169.
Safety requirements for mounded Storage facilities are covered in OISD-STD-150. The requirements for Auto LPG Dispensing Stations are covered in OISD-STD-210.
The green belt /buffer zone beyond the installation boundary is outside the scope of this standard. Such provisions may be considered based on local environment / security requirements.
3.0 DEFINITIONS
Approved Type : Any equipment which has specific approval for use under specified conditions by competent authority or authorised person as the case may be.
Area Classification : It is a method of classifying an area zone wise/ group wise based on the presence of explosive gas/ vapour - air mixture vis-a-vis the requirement of precautions for construction and use of electrical apparatus.
Bonding : Bonding is the process by which two electrical conducting bodies are connected using a conductor to maintain electrical continuity to prevent sparking between two conducting bodies.
Bulk Vessels : A pressure vessel used for more than 1000 litres water capacity for storage or transportation of LPG.
Bullet : A horizontal cylindrical pressure vessel used for storage or transportation of LPG by rail/ road.
Compressed Gas : Any permanent gas, liquefiable gas or gas dissolved in liquid under pressure or gas mixture which in a closed container exercises a pressure either exceeding 2.5 kg/sq.cm. abs @ 15 oC or a pressure exceeding 3.0 kg/Sq.cm. abs @ 50 oC or both.
Cylinders : A portable LPG container upto 1000 litres water capacity used for both domestic and industrial purposes.
Explosive mixture : It is a mixture of combustion agent (oxidising product-gas, vapour, liquid or solid) and a fuel (oxidisable product - gas, liquid or solid) in such proportions that it could give rise to a very rapid and lively oxidisation reaction liberating more energy than is dissipated through conduction and convection.
Earthing : Earthing is the provision of a safe path of electrical current to ground, in order to protect structures, plant and equipment from the effects of stray electrical current, and electrostatics discharge.
Filling Ratio : It is the ratio of weight of LPG in a container to the weight of water the same container can hold at 15 oC.
Fire safe : As applied to valves, it is the concept of controlling the leakage to an acceptable level after damage encountered during and after the fire achieved by dual seating.
Fire proofing : It is an insulation that provides a degree of fire resistance to protect substrates like vessels, piping and structures for a predetermined time period against fire.
Flammability : It is the percentage of volume of any flammable vapour in air-vapour mixtures capable to form an explosive mixture.
Flammable (or Inflammable) : Any substance which when tested in a specified manner will ignite when mixed with air on contact with a flame and will support combustion.
Gas-Free : it means the concentration of flammable or toxic gases or both in a pressure vessel or pipeline is within the safe limits specified for persons to enter and carryout hotwork in such vessels/ pipelines.
Horton Sphere : A spherical pressure vessel used for storage of LPG.
Hot Work : It is an activity which may produce enough heat to ignite a flammable air-hydrocarbon mixture or a flammable substance.
Installation : The facilities where LPG is stored or loading/ unloading operations or bottling operations are carried out.
Kerb Wall : A wall of appropriate height and size constructed of suitable material and designed to contain the LPG spillage and to direct it to a safe location around the storage vessel.
Liquefied Petroleum Gas (LPG) : The term applies to a mixture of certain light hydrocarbon predominately C3 & C4, derived from petroleum & natural gas which are gaseous at ambient temperature and pressure, may be condensed to a liquid state at normal ambient temperature by the application of moderate pressure and conforming to IS : 4576 or IS: 14861.
Purging : It is the act of replacing the atmosphere within a container by an inert substance in such a manner as to prevent the formation of explosive mixture.
Purging into Service : is the replacement of air in a closed system by an inert substance and replacement of the later by combustible gas, vapour, or liquid.
Purging out of service : is the replacement of normal combustible content of a closed system by an inert substance, and replacement of the later by air.
Tare Weight : The weight of the cylinder together with any fitting permanently attached to it including the weight of valve.
Maximum Working Pressure : It is saturated vapour pressure of LPG at 65 oC for LPG cylinders and 55 oC for bulk vessels.
Water Capacity : The maximum volume of water in litre that the a container can hold at 15 oC.
4..0 STATUTORY RULES / REGULATIONS
The LPG installation & various facilities are covered under many regulations and require specific approval / licence from concerned statutory authorities. The various regulations applicable to LPG installation facilities are as below :
a. Gas Cylinders Rules, 1981 (under Indian Explosives Act,1884)
b. Static & Mobile Pressure Vessels (unfired) Rules-1981 (Under Indian Explosives Act 1884).
c. The Factories Act, 1948.
d. Indian Electricity Rules
e. The Standards of Weight & Measures Rules - 1987 Under Weight & Measures Act - 1976.
f. The Standards of Weight & Measures (Packaged Commodities Rules-1977)
g. Liquefied Petroleum Gas (Regulation of supply and distribution Order - 1993).
h. The Motor Vehicles Act - 1988.
i. Environmental Regulations :
Ø Water (Prevention & Control of Pollution) Act, 1974.
Ø Air (Prevention & Control of Pollution) Act- 1981
Ø The Environment (Protection) Act – 1986
Ø Manufacture, storage & import of Hazardous chemicals Rules - 1989.
Ø Guidelines for Environmental clearance of new projects - 1981.
In addition to the above Statutory regulations, there are various recommended guidelines emerging out of the various Committees set up by the Govt. of India from time to time for streamlining/ improving the safety standards of LPG Bottling/ Distribution: