Ex ELECTRICAL RISK MANAGEMENT IN HAZARDOUS INDUSTRIES & SELECTION OF

Ex ELECTRICAL RISK MANAGEMENT IN HAZARDOUS INDUSTRIES & SELECTION OF ELECTRICAL EQUIPMENT FOR FLAMMABLE ATMOSPHERES P.G. Sreejith pillai [email protected] Chennai, INDIA www.cholaaxa.com P.G.Sreejith, Chennai

Ex Hydrocarbon Risks OISD Accident compilation (1996-1999): –Out of the total 71 accidents (5 lakh property loss/fatality/loss of 500MH/led to plant SD ), 66% were fire accidents –47% accidents happened during operational jobs –Causes of accidents: - 71% human error - 11% Failure of plant - 18% Presence of ignition source Is the above ‘accident cause’ grouping correct? P.G.Sreejith, Chennai

Ex Hazardous Areas-Definitions Petroleum Rules, 1976 An area shall be deemed to be a hazardous area, where: – petroleum having FP below 65 deg C or any inflammable gas or vapour in concentration capable of ignition is likely to be present –petroleum or any inflammable liquid having FP above is likely to be refined, blended or stored at or above its FP IS 5572 –Hazardous area is an area in which an explosive gas atmosphere is present, or likely to be present, in quantities such as to require special precautions for the construction, installation and use of electrical apparatus. P.G.Sreejith, Chennai

Ex COAL MININING SAFETY & CRUDE WAYS OF DETECTING METHANE GAS!! In the 1700's, certain gases or the lack of oxygen were detected with various hit and miss types of detection. The candles on miners caps, or if carried by the miner, would either go out from the lack of oxygen or the flame would get larger with a different coloring of the flame if certain gases were in the area. Of course, in some instances these open flames caused fires or explosions. By 1815, the Davy's Safety Lamp came into use in the mines. This certainly changed the way for miners to check for certain gases. They took these canaries in small cages with them down the coal mines where they worked. The canaries were the miners alarm signal to show them when the coal-gas levels got too high. The canary stopped singing and was most likely to be laid feet up on the bottom of the cage, poisoned by the mine gas. P.G.Sreejith, Chennai

Ex Why Area Classification? HAC is a method of analyzing and classifying the environment where explosive gas atmospheres may occur to allow the proper selection of electrical apparatus to be installed in that environment. Ignition sources not considered –ESD –Sparks –Lightning –Flames/Fires –Hot surfaces IS 5572 –HAs are classified in zones based on the frequency of the appearance and the duration of an explosive gas atmosphere. P.G.Sreejith, Chennai

Ex Why Zoning? Leak Potential & Presence of Ignition Sources Hazardous properties of hydrocarbons Safe selection (& optimization) of Electrical Equipment P.G.Sreejith, Chennai

Ex AREA CLASSIFICATION How many Zones as per Indian standards? European & American classifications (Zones and Divisions) Why not ‘blanket’ zoning? Is the 4th Zone really a ‘safe’ zone? Who should do HAC-Electrical or Process Engineer? P.G.Sreejith, Chennai

Ex HAC as per IS 5572 is not applicable for: Mining applications Explosive manufacturing Areas where ignitable dusts & fibers are present Catastrophic failures Ignition sources other than electrical apparatus P.G.Sreejith, Chennai

Ex Zone 0 -Typical areas (Continous grade) Vapour space above: – closed process vessels, –storage tanks –closed containers, –areas containing open tanks of volatile, flammable liquid P.G.Sreejith, Chennai

Ex How to identify Zone 1 areas (IS 5572) ? (Primary grade) Flammable gas or vapour concentration is likely to exist in the air under normal operating conditions Flammable atmospheric concentration is likely to occur frequently because of maintenance, repairs or leakage Flammable liquid or vapour piping system (containing valves, meters, or screwed or flanged fittings) is in an inadequately ventilated area The area below the surrounding elevation or grade is such that flamamble liquids or vapours may accumulate therein P.G.Sreejith, Chennai

Ex Zone 1 -Typical areas Imperfectly fitting peripheral seals on floating roof tanks Inadequately ventilated pump rooms for flammable gas or for volatile, flammable liquids Oily waste water sewer / basins Loading / unloading gantries of hazardous products P.G.Sreejith, Chennai

Ex Typical Zone 2 areas (IS 5572) ? (Secondary grade) The system handling flammable liquid or vapour is in an adequately ventilated area and is so designed and operated that the explosive or ignitable liquids, Vapours or gases will normally be confined within closed containers or closed systems from which they can escape only during abnormal conditions such as accidental release of a gasket or packing The flammable vapours can be conducted to the location as through trenches, pipes or ducts Locations adjacent to Zone 1 areas Pressurized rooms where flammable gas / vapour can enter in the case of failure of positive mechanical ventilation P.G.Sreejith, Chennai

Ex Safe Areas -Typical areas The following locations are considered safe from the point of view of electrical installation: Areas where the piping system is without valves, fittings, flanges or similar appurtenances Areas where flammable liquids or vapours are transported only in suitable containers or vessels Areas where permanent ignition sources area present like area where combustion gases are present, for example flare pits, tips, other open flames 7 hot surfaces DG shed room / shed having adequate ventillation GT installation meeting the ventilation (12 ACPH) , pressurization (0.5 mbar )and flange (not more than one pair of flanges inside the turbine room) requirements P.G.Sreejith, Chennai

Ex HAC- Comparison North America (NFPA / API/ NFPA 70E or NEC) –Hazardous Areas: - Division I- Z0 Z1 - Division II- Z2 –Hazardous Locations - Class I-Flammable Gases / Vapour - Class II- Combustible dust - Class III- Combustible fibres or flyings –Gas / vapour grouping - A, B, C, D, E, F & G Japan –Hazardous Areas - Classes 1, 2 & 3 –Gas / vapour groups - G1, G2, G3, G4, G5 & G6 P.G.Sreejith, Chennai

Ex A FEW RELEVANT DEFENITIONS Flash Point - A, B, C Ignition Temperature Explosive Limits (based on MIE) –LEL –UEL P.G.Sreejith, Chennai

Ex HAZARDOUS AREA CLASSIFICATION-Guidelines Factors to be considered (IS 5572) Vapour / Gas Density Effect of Air Current Identification of leak scenarios P.G.Sreejith, Chennai

Ex GENERAL CONSIDERATIONS In the absence of walls, enclosures, etc. & air currents, vapour/gas dispersion will depend on density & velocity. Denser gas/vapour will disperse downward and outward, lighter gases upward & outward.HA for a single leak source would be a circle. Vapours / gas released(high density releases) at or near ground level, will be found below ground, thus altering the shape of HA. P.G.Sreejith, Chennai

Ex EFFECT OF AIR CURRENT Winds alter the shapes of hazardous areas A mild breeze may extend the HA and a strong wind could dilute the flammable concentration,making it non-hazardous But what are logically to be considered are the most unfavourable conditions P.G.Sreejith, Chennai

Ex HEAVIER-THAN-AIR GASES & VAPOURS Open -Air Situations (freely ventilated Process Areas) –Figures 1 ,2) –Figures 3 & 4 –In case of petroleum pipelines (where well-maintained valves, fittings, and meters and in well-ventilated areas or in a pit), Zone 2 A/G shall be 4m in all directions, from the potential leak source. Pit will be considered as Zone 1. –Zone 1 Zones 1 or 2 (unless separated by a fire wall) P.G.Sreejith, Chennai

Ex LIGHTER-THAN-AIR GASES & VAPOURS –Vapour density of 0.75 is considered as the boundary between lighter and heavier gases / vapours as a safety measure HA of a leak source located in air Source of hazard 4.5 m 8.0 m R 4.5 m H 4.5m Zone 2 P.G.Sreejith, Chennai

Ex How to classify areas? Mark in elevation and plan drawings Separate identification (hatching) for various zones –Zone 0 –Zone 1 –Zone 2 Frequency of HAC? P.G.Sreejith, Chennai

Ex An experienced process engineer’s judgement in visualizing leak scenarios and classifying hazardous areas is the most CRUCIAL factor in the HAC exercise P.G.Sreejith, Chennai

Ex API RP 500- HAC Guidelines Adequacy of ventilation Accident record of the plant / business group / industry sector/maintenance standard adopted in the plant Sound judgement & Experience of the engineer who carries out HAC P.G.Sreejith, Chennai

Ex AREA CLASSIFICATION AS A TOOL FOR RISK ASSESSMENT A LOGICAL APPROACH Perceived Limitations on the present HAC approach: –Ignition sources not considered –Reduction of zone areas & relaxation of zone designations not considered –Blinkers -On Approach , High cost, blanket zoning, narrow & easy approach or in short, the full potential of HAC is not utilized at present P.G.Sreejith, Chennai

Ex AREA CLASSIFICATION AS A TOOL FOR RISK ASSESSMENT EXTENDING HAC PROCEDURE –Additional steps - After applying the present HAC procedure, assess all ignition sources - Assess the grade of release using HAC-based risk assessment matrix - Assessing the ventilation & evaporation aspects of the chemicals considered –Applying the new HAC procedure P.G.Sreejith, Chennai

Ex HAC-based Risk Assessment Matrix Grade of Ignition Grade of Release Continous Continous Frequent Infrequent Very Infrequent Unacceptable Unacceptable unless low consequences Risk Assessment required-look at consequences Acceptable (e.g. Ex i apparatus) Acceptable (e.g. Ex d apparatus ) Primary Unacceptable Unacceptable Secondary Risk Assessment required-look at consequences but probably unacceptable Acceptable but examine catastrophic releases Risk Assessment required-look at consequences but Acceptable (E.g. Ex n apparatus) Acceptable Acceptable but examine catastrophic releases Acceptable Acceptable Non-Hazardous P.G.Sreejith, Chennai

Ex AREA CLASSIFICATION AS A TOOL FOR RISK ASSESSMENT CONCLUSION A logical extension of the present HAC methodology & not a radical approach New European legislation, ATEX 118a Directive will be on similar lines The new focussed & practical HAC approach will make HAC exercise more cost-effective A SAFE APPROACH? P.G.Sreejith, Chennai

Ex COMPARISON OF ZONES & DIVISIONS Classified area Z0 Estimated % (Divisions) Normally present 5% 60% Occasionally in normal operations Z1 D2 Not normally present Estimated % (Z) 2% Continuously D1 Z2 Time that haz. gases are present in ignitable 95% P.G.Sreejith, Chennai 40%

Ex PERCENTAGE OF CLASSIFIED AREAS C L A Z2 S S I F I Z1 E D A Z0 R E A S O 10 100 20 30 40 P.G.Sreejith, 50 Chennai 60 70 80 90

Ex HAC- A RECAP P.G.Sreejith, Chennai

Ex HAC-RELEVANT INTERNATIONAL STANDARDS API RP 500- Area Classification of Petroleum Installations IEC 79-10 :1995 -Electrical Apparatus for Explosive Gas Atmospheres, part 10 Classification of hazardous areas IP Part 15, 1990- Area Classification Code for Petroleum Installations BS EN 60079-10, : 1996 -Electrical Apparatus for Explosive Gas Atmospheres, part 10 Classification of hazardous areas BS 5345, 1983-Selection, installation and maintenance of electrical apparatus for use in potentially explosive atmospheres (other than mining applications or explosive manufacturing), part 2, Recommendations for particular industrial situations P.G.Sreejith, Chennai

Ex USEFUL REFERENCE BOOKS ON HAC Classification of Hazardous Locations,I.Chem. E. Cox, A.W., Lees, F.P. and Ang, M.L, 1990 IP Model Code of Safe Practice, 1990, Part 15, Area Classification Code for Petroleum Installations NFPA 69, 1992, Explosion Prevention Systems ICI/RoSPA, 1972, ICI Electrical Installations Code NFPA 325M, Properties of Flammable Liquids, gases and solids Electrical Safety in Hazardous Locations, William Calder & Ernest C. Magison P.G.Sreejith, Chennai

Ex SELECTION OF ELECTRICAL EQUIPMENT IN HAZARDOUS AREAS P.G.Sreejith, Chennai

Ex SELECTION OF ELECTRICAL EQUIPMENT IN HAZARDOUS AREAS How to select equipment for various zones? Selection Criteria –Gas Grouping (based on ignition energy) –Temperature Classification –Classified Zones P.G.Sreejith, Chennai

Ex TEMPERATURE CLASSIFICATION T Class Max. Surface Temperature (Deg. C) T1 T2 450 T3 200 T4 300 135 T5 100 T6 85 P.G.Sreejith, Chennai

Ex GAS GROUP CLASSIFICATION (based on MESG & MIE) Gas group I –Methane Gas group II A –Ammonia, CO, Propane, Butane, Benzene, Acetone, Methanol Gas group II B –Butadiene, Ethylene, Ethylene Oxide, Diethyl Ether Gas group II C –Hydrogen Which is the most hazardous group ? P.G.Sreejith, Chennai

Ex GAS GROUP & TEMPERATURE CLASSIFICATION-VARIOUS GASES/VAPOURS (IS 13408 Part I) S No Name of the chemical Minimum Flash point Iignition Ignition Deg. Cen. temperatur Curre nt Methane I, LEL UEL 5% 15% e (MIC) mA 1 Flammable limit (Deg C) 85 - 595 - - 630 105 mg/l 45 - 425 2.7% 34% 70 - 470 2% 9.5% 24 - 305 1.5 % 100% T1 2 Ammonia 200 mg/l II A T1 3 Ethylene II B T2 4 Propane II A T1 5 Acetylene II C T2 P.G.Sreejith, Chennai

Ex GAS GROUP & TEMPERATURE CLASSIFICATIONVARIOUS GASES/VAPOURS Gas Energy Representative Gas Group I II A IIB IIC Ignition (mj) Methane 280 Propane 260 Ethylene 95 Hydrogen 18 P.G.Sreejith, Chennai

Ex FLAMMABLE MIXTURE, MIG, EXPLOSION P.G.Sreejith, Chennai

Ex RECOMMENDED PROTECTION METHODS FOR ZONE O No electrical equipment should be allowed. When this is not practicable, Ex ‘ i ‘ (ia or ib) apparatus or circuits to be used No transformers, motors, lights, switch gear or control gear P.G.Sreejith, Chennai

Ex RECOMMENDED PROTECTION METHODS FOR ZONE 1 Motors- Ex d, Ex p Transformers & Capacitors - Ex d Control & Instrument Transformers - Ex i Lighting Fitting - Ex d Switch Gear & Control Gear - Ex d Communication/ Telephone equipment/Meters - Ex i Portable Hand Lamps- Ex i *Ex o, Ex q type equipment are also allowed for use as per IS 5571 P.G.Sreejith, Chennai

Ex RECOMMENDED PROTECTION METHODS FOR ZONE 2 Motors- Ex d, Ex p, Ex n, Ex e, Transformers & Capacitors - Ex d, Ex p (auxiliary devices to be located in pressurized room/hermetically sealed / intrinsically safe) Control & Instrument Transformers - Ex i Lighting Fitting - Ex d, Ex e, Ex n Switch Gear & Control Gear - Ex d, Ex o, Ex Communication/ Telephone equipment/Meters - Ex i Portable Hand Lamps- Ex i * Minimum IP 55 (for UN-insulated parts) and IP 44 (for insulated parts) if Ex e protection is used for outdoor applications P.G.Sreejith, Chennai

Ex Ex EXPLOSION-PROTECTION EQUIPMENT P.G.Sreejith, Chennai

Ex EXPLOSION-PROTECTION METHODS / EQUIPMENT -Popular types Flameproof (EX d) Increased Safety (Ex e ) Non-Sparking (Ex n ) Pressurization (Ex p ) Intrinsically Safe (Ex i ) P.G.Sreejith, Chennai

Ex OTHER TYPES OF EXPLOSION PROTECTION- Not so popular types Powder filled Ex ‘q’ type Oil immersed Ex ‘o’ type Special Ex ‘s’ type P.G.Sreejith, Chennai

Ex Definition as per IS 2148: EX ‘d’ Type FLAMEPROOF EQUIPMENT US- Explosion-Proof, UK- Flame-Proof, GERMANY - Pressure-Proof A type of protection in which the parts can ignite an explosive atmosphere are to be placed in an enclosure, which can withstand the pressure developed during internal explosion of an explosive mixture, and which prevents the transmission of the explosion to the explosive atmosphere surrounding the enclosure FLAMEPROOF EQUIPMENT- A MISNOMER? P.G.Sreejith, Chennai

Ex FLAMPROOF (EXPLOSION-PROOF) PROTECTION (Ex ‘d’) Assumptions based in IS 2148 are: Flammable gases / vapours, if present in atmosphere will enter the enclosure The apparatus will be selected, installed, operated and maintained within the acceptable ratings. The maintenance and use of FLP equipment shall be so that its safety will not be impaired, is the responsibility of the user The electric circuit of the FLP equipment will have all required protection devices Sparking which will ignite a flammable gas or vapour, may occur at any part of the equipment contained in the enclosure in normal operation due to an internal fault due to insulation failure, etc. P.G.Sreejith, Chennai

Ex FLAMPROOF (EXPLOSION-PROOF) PROTECTION FLAME PATH - Width of Joint –Minimum GAP - Diametrical Clearance –Maximum P.G.Sreejith, Chennai (Ex ‘d’)

Ex FLAMPROOF (EXPLOSION-PROOF) PROTECTION (Ex ‘d’) Maximum gaps and flame path for gas groups depends on ignition energies of the gas / vapour and the volume of the enclosure For example, for IIB gas group, for 100 Cubic cm volume, for flanged joints: –Flame Path - 6 mm –Maximum Gap - 0.3 mm For II C Hydrogen, 100 cubic cm volume, for flanged joints: –Flame path - 9.5 mm –Maximum Gap - 0.1 mm P.G.Sreejith, Chennai

Ex FLAMEPROOF EQUIPMENT- CONSTRUCTIONAL REQUIREMENTS USE OF APPROVED MATERIAL WITHOUT THE USE OF INCENDIVE FRICTIONAL SPARKING EQUIPMENT SHOULD WITHSTAND ROUGH USAGE EQUIPMENT SHALL BE ADEQUATELY STRONG TO WITHSTAND ALL REQUIRED TESTS THE EFFECTIVE THREADED METAL TO METAL JOINTS SHALL HAVE A MINIMUM OF 5 FULL UNINTERRUPTED ENGAGED THREADS & A MINIMUM EFFECTIVE UNINTERRUPTED DIRECT AXIAL LENGTH OF THREADED ENGAGEMENT OF 9 mm THERE SHALL BE NO INTENTIONAL GAP BETWEEN JOINT SURFACES NO PACKING MATERIAL SHALL BE USED BETWEEN OPPOSED SURFACES TO FORM A FLAMEPROOF JOINT IF COMPRESSIBLE PACKING MATERIAL OR A GASKET IS NECESSARY TO SEAL A JOINT (eg. IP) THE PACKING SHALL BE APPLIED AS A SUPPLMENT TO, BUT SHALL NOT BE INCLUDED IN THE FLAMEPROOF JOINT ANY DISPLACEMENT, DAMAGE, INTEGRATION OR OMISSION OF THE PACKING SHALL NOT RESULT IN THE FLAMPROOF NATURE OF THE JOINT BEING ADVERSELY P.G.Sreejith, Chennai

Ex FLAMEPROOF EQUIPMENT- CONSTRUCTIONAL FEATURES EX d typical marking: EEx d IIB T5 P.G.Sreejith, Chennai

Ex INTRINSICALLY SAFE EQUIPMENT & CIRCUITS (Ex ‘i’ ) Definition as per IS 5780 A type of protection which a circuit or part of the circuit is intrinsically safe when any spark or thermal effect produced normally is incapable, under prescribed test conditions, of causing ignition of prescribed gas or vapour P.G.Sreejith, Chennai

Ex INTRINSICALLY SAFE EQUIPMENT & CIRCUITS (Ex ‘i’ ) (insert a small photo) Only electrical protective measure (protection technology by way of power limitation), the other protective techniques use mechanical means to prevent ignition from electrical faults (max. 30 volts or 50 mA) Ex ‘i’ apparatus is the one which has all the circuits within intrinsically safe Ex ‘i’ circuit is the one which has intrinsically safe barriers with Zenner diodes for power limitation Minimum IP 20 ingress protection P.G.Sreejith, Chennai

Ex INTRINSICALLY SAFE EQUIPMENT- Category- Ex ib Ex ib equipment shall be incapable of causing ignition in normal operation, with a single fault and with the following safety factors: –1.5 in normal operation and with one fault –1.0 with one fault, if the equipment contains no unprotected switch contacts in parts likely to be exposed to a potentially explosive atmosphere and the fault is self-revealing EX i typical marking: EEx ia IIC T5 P.G.Sreejith, Chennai

Ex INTRINSICALLY SAFE EQUIPMENT (Ex ‘i’ ) Cell phone explosion accident in an offshore platform Fuel outlets- restricted cell phone usage? P.G.Sreejith, Chennai

Ex INCREASED SAFETY EQUIPMENT (Ex ‘e’) Definition as per IS 6381 A type of protection by which measures are applied so as to prevent with a minor degree of security, the possibility of excessive temperature and the occurrence of arcs or sparks in the interior and the external parts of electrical apparatus which does not produce them in normal service P.G.Sreejith, Chennai

Ex INCREASED SAFETY EQUIPMENT (Ex ‘e’) Stringiest construction methods to ensure that no sparks, excessive temperature are produced Careful terminal design Use of good quality insulation material Use of special materials to protect the enclosure against impact, ingress of dust & moisture Can be used for I, II A, B, C gas groups Permitted for us in T1, T2, T3 classes only Terminal with minimum IP 54 ingress protection EX d typical marking: EEx e IIA T3 P.G.Sreejith, Chennai

Ex PRESSURIZATION TYPE (Ex Definition as per IS 7389 ‘p’ ) A type of protection by which the entry of surrounding atmosphere into the enclosure of the electrical apparatus is prevented by maintaining inside the said enclosure, a protective gas at a higher than that of the surrounding atmosphere P.G.Sreejith, Chennai

Ex PRESSURIZATION TYPE (Ex TYPES ‘p’ ) Dynamic Pressurization (DP) or pressurization by continuos circulation of protective gas (purging) –DP is a method of maintaining pressure in an enclosure in which after purging the protective gas is passed continously through the enclosure at a pressure above that of the specified minimum and discharged to the outside atmosphere –Static Pressurization or pressurization with leakage compensation - Air supplied & pressurized continously from a non-hazardous area to avoid ingress of flammable gases / vapour inside the enclosure P.G.Sreejith, Chennai

Ex PRESSURIZATION TYPE (Ex ‘p’ ) Pressurized Equipment Ingress protection minimum IP 4X Over pressure 1.5 times or 0.2 kPa Material of construction should be flame retardant, self- extinguishing and should not be affected by protective gas P.G.Sreejith, Chennai

Ex PRESSURIZATION TYPE (Ex ‘p’ ) Pressurized Equipment / Panels A minimum overpressure of 0.2 kPa (2mbar) with reference to external atmospheric pressure Air intake from a safe area Exhaust duct outlet to be located in safe area Zone 1- can be used if there is no spark in normal service Zone 1 or 2 -if ejection of spark is prevented by effective device and rapid suction of external atmosphere is prevented P.G.Sreejith, Chennai

Ex Minimum actions of Failure of Protective Gas for Ex ‘p’ Area Zone 2 Zone 1 Enclosure does not contain Ignition-capable apparatus No Action required Alarm P.G.Sreejith, Chennai Enclosure contains I-C Apparatus Alarm Alarm with trip

Ex NON-SPARKING TYPE EQUIPMENT (Ex ‘n’ ) –Definition as per IS 8289 A type of protection applied to electrical apparatus such that , in normal operation it is not capable of igniting a surrounding atmosphere and a fault capable of causing ignition is not likely to occur EX n typical marking: EEx n II T5 P.G.Sreejith, Chennai

Ex NON-SPARKING TYPE EQUIPMENT (Ex ‘n’ ) Equipment construction in such a way that in normal operation, it is incapable of igniting a surrounding explosive atmosphere and a fault incapable of causing ignition Hermetically sealed type Restricted breathing type Careful design of terminals - SUBSTANTIAL COST SAVING Applications –Tools –Equipment P.G.Sreejith, Chennai

Ex POWDER FILLED TYPE EQUIPMENT ( Ex ‘q’) Equipment enclosure filled with quartz /sand so that in normal operating condition, any arc occurring within the enclosure of electrical equipment will not ignite the surrounding atmosphere No ignition shall be caused either by flame or by excessive temperature of the surfaces of the enclosure Enclosure constructional features: High mechanical strength Ingress protection Powder filled Insulation of enclosed equipment P.G.Sreejith, Chennai

Ex OIL IMMERSED TYPE EQUIPMENT (Ex ‘o’) Protection technique in which the equipment or its parts are immersed in oil in such a way that an explosive atmosphere which, may be above the oil or outside the enclosure cannot be ignited. Oil used shall be mineral oil confirming to relevant standards Constructional features: – Fully enclosed, leak-proof enclosure –Oil level indicator Transformers, Switch gears, Control gears P.G.Sreejith, Chennai

Ex SPECIAL TYPE EQUIPMENT (Ex ‘s’) This is a concept that has been adopted to permit the certification of those types of equipment which by their nature, do not comply with the constructional or other requirements specified for equipment with established types of protection but which, nevertheless, can be shown, wherever necessary, by test to be suitable for use in hazardous areas in prescribed zones This concept permits flexibility on the part of certifying and assessment authorities in their approach to applications for certification of equipment the use of which would otherwise not permitted in hazardous areas on account of non-compliance with the requirements of standards for established types of protection. This allows flexibility of approach to innovative ideas and new designs, the development of which otherwise be obstructed. Examples: –Factory sealed hand lamps, Encapsulation (Ex ‘m’ type), Gas detection apparatus P.G.Sreejith, Chennai

Ex Add an appropriate photo INGRESS PROTECTION (IP) P.G.Sreejith, Chennai

Ex Insert a IP photo with gasket IP Ingress of Liquid XY Degree of Protection of persons against contact with or moving parts inside the enclosure & Protection Of Equipment against Solid P.G.Sreejith, Chennai ingress

Ex IP Types and Protection Details FIRST NUMERAL SECOND NUMERAL 0 No protection 0 No protection 1 Objects greater than 50 mm 1 Vertically dripping 2 Objects greater than 12 mm 2 Angular dripping 3 Objects greater than 2.5 mm 3 Sprayed water 4 Objects greater than 1.0 mm 4 Splashed water 5 Dust - protected 5 Water jets 6 Dust tight 6 Heavy seas 7 Effects of immersion 8 Indefinite immersion P.G.Sreejith, Chennai

Ex Indian Standards for Various Protection Techniques IS 5571 Guide For Selection Of Electrical Equipment For Hazardous Areas IS 5572 –Part I Classification of Hazardous Areas for Electrical Installations IS 13408 Part I, II, III Code of Selection, Installation and Maintenance of Electrical Apparatus for Use in Explosive Atmospheres IS 8239 Classification of Maximum Surface Temperature of Electrical Equipment for Use In Explosive Atmospheres IS 6381 Construction and testing of Electrical Apparatus with type of protection ‘e’ IS 2148 Flameproof Enclosures of Electrical Apparatus P.G.Sreejith, Chennai

Ex Indian Standards for Various Protection Techniques IS 13346 General Requirements for Electrical Apparatus for Explosive Gas Atmospheres IS 5780 Specification For Intrinsically Safe Electrical Apparatus and Circuits IS 8240 Guide for Electrical Equipment for Explosive Atmospheres IS 2147 Degrees of Protection Provided by Enclosures For Low Voltage Switch Gear & Control Gear IS 4691 Degrees of Protection Provided by Enclosures For Rotating Electrical Machinery IS 8241 Methods of Marking for Identifying Electrical equipment for Explosive Atmospheres IS 8224 Specification for Electric Lighting fitting for Explosive Atmospheres IS 8289 Electrical Equipment with Type of Protection ‘n’ IS 7389 Specification for Pressurized Enclosures IS 2206 (PART I,III) Specification for Flame proof Electric Light Fixtures P.G.Sreejith, Chennai

Ex INSTALLATION & MAINTENANCE OF ELECTRICAL EQUIPMENT IN HAZARDOUS AREAS P.G.Sreejith, Chennai

Ex INSTALLATION GUIDELINES OF ELECTRICAL EQUIPMENT IN HAZARDOUS AREAS (IS 5571) Adequate precautions to avoid ESD & Lightning to be implemented Use of light alloy (Mg, Al, Ti, ) material to be assessed critically in HAs due to its incendive properties Where reasonably practical, electrical apparatus generally and switch & control apparatus should be installed outside the Hazardous Areas Electrical apparatus may be installed in open air in a non-hazardous area P.G.Sreejith, Chennai

Ex INSTALLATION GUIDELINES OF ELECTRICAL EQUIPMENT IN HAZARDOUS AREAS Equipment designed for higher gas groups can be used for less hazardous gas groups ( for e.g., Equipment certified for II C can be used for II A, B or I) Portable hand-lamps, communication equipment and other test equipment shall be Ex i type All equipment shall be installed so as to avoid mechanical damage Earthing shall be carried out as per IS 3043 Bonding of all pipeline flanges should be carried out so as to avoid Electro-static discharges Internal earthing to be provided for all FLP equipment in addition to external earthing P.G.Sreejith, Chennai

Ex INSTALLATION GUIDELINES OF ELECTRICAL EQUIPMENT IN HAZARDOUS AREAS All circuits and apparatus in Hazardous Areas should be provided with means to ensure quick disconnection in the event of any fault (O/C, S/C or E/F) Protection & Control apparatus shall be normally located in non-HAs but if unavoidable, they may be of the right protection type All electrical apparatus (for every apparatus or sub-groups) should be provided with an effective means of isolation, including neutral Metal conduits, armoured cables Correct terminations using proper sized cable glands (doublecompression, FLP type) Unused cable openings of all electrical apparatus shall be closed with plugs suitable for the type of protection P.G.Sreejith, Chennai

Ex INSTALLATION GUIDELINES OF ELECTRICAL EQUIPMENT IN HAZARDOUS AREAS Copper or Aluminium (above 16 sq. mm only) conductors can be used FLP plugs & sockets should have preferably PUSH-IN, TWIST-ON type to avoid ignition while insertion or removal Adequacy of IP equipment Test equipment –Insulation Resistance megger shall be Ex i type –Earth Megger shall be Ex i type –Hotspot Detection equipment P.G.Sreejith, Chennai

Ex MAINTENANCE RECOMMENDATIONS IN HAZARDOUS AREAS FLP Equipment –All bolts in place –All openings closed –No site modification / alteration – Internal & external earthing –Double-Compression, FLP cable glands –No physical damage –No damage to Flame path –All threaded connections-minimum 5/ 6 threads engagement –Flange faces to be smooth & original (to be careful while opening stuck covers) P.G.Sreejith, Chennai

Ex MAINTENANCE RECOMMENDATIONS IN HAZARDOUS AREAS Light alloy paint even for the purpose of maintenance must not be applied on any external surface of the equipment to prevent inscendve frictional sparking Equipment shall not be tampered to open covers, etc. No components shall be added or removed or even replaced. This has to be done after getting re-certified by the OEM A scheme of regular inspection & maintenance of the items should be made on the basis of guidelines / standards. Any equipment which is originally flameproof may loose its integrity if not maintained properly The equipment should be de-energized before attempting any repair P.G.Sreejith, Chennai

Ex MAINTENANCE RECOMMENDATIONS IN HAZARDOUS AREAS Drawings /Records –Updated SLD –Updated HAC drawing –Drawing with various equipment installed in various identified zones –Certification / re-certification records –IR / ER records Sufficient Spare stock of critical equipment (various Ex types) Solid obstruction(steel structures, walls, other electrical equipment) effects (close to equipment flanges) – IIC - 40 mm clearance –IIB - 30 mm –II A - 10 mm –I - no clearance envisaged P.G.Sreejith, Chennai

Ex MAINTENANCE RECOMMENDATIONS IN HAZARDOUS AREAS Integrity of IP equipment –Use of gasket is permitted if certified as part of the equipment –No sealing of flange faces (this could affect the ability of the enclosure to withstand the maximum explosion pressure) –Application of non-setting grease or anti-corrosive agent is permissible –Non-hardening tape can be used in II A gas groups, II B tape is to be avoided and no use of tape in II C gas groups Insulation integrity to be periodically tested and maintained Maintenance personnel –Inspection, Maintenance, testing, replacement and repair in HAs shall be carried out by trained personnel only –Refresher training for them is essential P.G.Sreejith, Chennai

Ex MAINTENANCE RECOMMENDATIONS IN HAZARDOUS AREAS Periodic examination of flange gaps and flange faces for any effects of corrosion / damage, etc. Maintenance Tests (at an interval not exceeding 3 years) – IR measurements –Earth electrode resistance measurements –Earth loop resistance measurements –Operation & Setting of Protection devices P.G.Sreejith, Chennai

Ex MAINTENANCE RECOMMENDATIONS FOR VARIOUS Ex Types (except Ex d) Ex i - No addition / alteration of circuit components / power limitation barriers, etc. Check Ex p equipment / panels / rooms for low pressure interlock operations, periodic review of air in take stack location Terminations in Ex e, n types equipment Use of non-sparking tools “ELECTRICAL EQUIPMENT USED IN HAZARDOUS ARAES ARE SPECIAL AND THEY NEEDS TO BE TREATED SPECIAL” P.G.Sreejith, Chennai

Ex STATUTORY REGULATIONS & APPROVAL REQUIREMENTS P.G.Sreejith, Chennai

Ex Approval / Testing Agencies CMRI (Central Mining Research Instituite), Dhanbad, BIHAR CCoE (Chief Controller of Explosives), Nagpur BIS (Bureau Of Indian Standards) DGMS (Director General Mine Safety), Dhanbad, BIHAR DGFASLI (Director General of Factory Advice Service and Labour Instituites), Mumbai P.G.Sreejith, Chennai

Ex Statutory Regulations For Plants Utilizing Hydrocarbons Petroleum Act, 1884 –Petroleum Rules, 1976 Explosive Act, 1934 –Explosive Rules, 1983 –Gas Cylinder Rules, 1981 –Static & Mobile pressure Vessel (Unfired) Rules, 1981 CCoE, Department of Explosives is entrusted with the responsibility of administration of the above statutory rules in India P.G.Sreejith, Chennai

Ex Statutory Regulations For Plants Utilizing Hydrocarbons Petroleum Rules, 1976 (Chapter IV) Static & Mobile Pressure Vessels (U) Rules, 1981 ( Rule 31) Gas Cylinder Rules, 1981 (Rule 21) P.G.Sreejith, Chennai

Ex EXTRACTS FROM PETROLEUM ACT, 1934 Hazardous Area- Definition –An are shall be deemed to be an hazardous area, where: –i) petroleum having FP below 65 deg. C or any other flammable gas or vapour in concentration capable of ignition is likely to be present –ii) petroleum or any inflammable liquid having FP above 65 deg centigrade is likely to be refined, blended, handled or stored at or above its FP P.G.Sreejith, Chennai

Ex EXTRACTS FROM PETROLEUM ACT, 1934 HAC- Zones 0, 1, 2 Earth resistance values: –4 ohm for electrical systems –10 ohms for non-current carrying metallic parts –all joints in pipelines, valves, etc. shall be bonded and the earth resistance between each joint shall be 1 ohm Hazardous Areas as per 4th Schedule: –-In-line with IS 5571 Tables 1 & 2 (as per Form XIII) –Inter-Distances between tanks (with Classes A, B, C products) –Distance between tanks and tankers, offices, motors P.G.Sreejith, Chennai

Ex CMRI, Dhanbad -Approval Agency for Electrical Equipment for Use In Hazardous Areas Equipment testing and approvals (for all gas groups- I, II A, IIB, IIC) Testing and approval required for modified equipment P.G.Sreejith, Chennai

Ex Equipment Approval Procedure Drawing and prototype submittal to CMRI Tests by CMRI Approval by CMRI ISI Certification (Tests by CMRI) as per applicable Indian Standards Approvals by: DGFASLI CCoE P.G.Sreejith, Chennai

Ex ELECTRICAL SAFETY AUDITING IN HAZARDOUS AREAS P.G.Sreejith, Chennai

Ex Focus Areas Original HAC drawings (IS 5572) Plant additions / alterations Installation of electrical equipment in hazardous areas (IS 5571) Valid applicable statutory approvals (CCoE) Maintenance of Electrical Equipment –FLP –Pressurized equipment –Earthing (internal & external) P.G.Sreejith, Chennai

Ex European ATEX Directive Advantages include CLEAR Zone marking, stringent quality requirements, very user-friendly Products will have to be re-certified as per the new harmonized ATEX standards CAT 3 (Zone 2) products will not require approval from a notified body (could be self-certified, if in-house test facilities are available) Use Directive ATEX137 ‘Protection of workers at Risk from Potentially Explosive Atmospheres’ –Another directive for user industries –Will be mandatory under EU laws in 2003 –Requirements - Documented evidence of analysis, HAC, inspections carried out - Use of ATEX certified (E & M) equipment & safety systems P.G.Sreejith, Chennai

Ex Auditing Checklists OISD 145 (Section 9) IS 5571 IS 5572 IS 13408 Part I, II, III (Code of practice for selection, installation & maintenance of Electrical equipment in potentially Explosive atmospheres) P.G.Sreejith, Chennai

Ex MAINTENANCE RECOMMENDATIONS IN HAZARDOUS AREAS Periodic examination of flange gaps and flange faces for any effects of corrosion / damage, etc. Maintenance Tests (at an interval not exceeding 3 years) – IR measurements –Earth electrode resistance measurements –Earth loop resistance measurements –Operation & Setting of Protection devices P.G.Sreejith, Chennai

Ex TOTAL RECAP HAC EQUIPMENT SELECTION VARIOUS EXPLOSION PROTECTION TECHNIQUES INSTALLATION , MAINTENANCE & AUDITING GUIDELINES STATUTORY REQUIREMENTS P.G.Sreejith, Chennai

Ex European ATEX Directive ATEX Directive 94/9/EC is adopted by the EU members & is concerning technical & legal requirements applicable for potentially explosive atmospheres CE marking is a pre-requisite if products are to be used in EU nations ATEX directive 100a will become mandatory on July 1, 2003 Equipment groups (non-mining) –CAT 1 (Zone 0) –CAT 2 (Zone 1) –CAT 3 (Zone 2) P.G.Sreejith, Chennai

Ex CHOLAMANDALAM AXA RISK SERVICES LTD. COMPANY PROFILE JV between Cholamandalam Investment & Finance Co. Ltd. (Part of Murugappa group) and AXA Insurance of France Offers customized Risk Management solutions to industrial clients in ASIA, which include: Business Continuity Planning, Risk Analysis, Electrical Safety Audits, Safety Audits as per IS 14489, Specialized safety training, Review of Fire Protection systems, etc. (as per NFPA, BIS, OISD,API, etc.) P.G.Sreejith, Chennai

Ex LET US MAKE OUR REFINERIES SAFER !!! THANK YOU!!! P.G.Sreejith P.G.Sreejith, Chennai