ExplosionProtection An International Comparison Guide for the Oil & Gas Industry Group A Group B Group C Group D Group Type Atmospheres containing... Acetylene & similar gases Hydrogen & similar gases Ethylene, & similar gases Propane & similar gases NB: The information in this wall chart is for guidance only. For detailed information see the relevant Directives, Regulations and Standards or contact us at [email protected] for more information, visit www.pyroban.com * The Division classifications stated above are in accordance to Class 1 areas. for more information, visit www.pyroban.com for more information, visit www.pyroban.com for more information, visit www.pyroban.com USA & CANADA NEC / CEC (National Electrical Code / Canadian Electrical Code) EUROPE ATEX (Atmosphere Explosive) Explosion Protection Essential Requirements The NEC & CEC Division systems use Classes and Groups to identify a hazard. The systems refer to Class I environments, where gases & vapours repre- sent an explosive atmosphere, most commonly present in the oil and gas industry. • , II, 2G, Ex, de, IIC, T5 AUSTRALIA Groups further define the type of hazard in a Class I location: Group A hazards represent gases with extremely high explosion pressures while Group D represent gases with lower explosion pressures. Ex Standard Typical Example of Equipment Marking ATEX 94/9/EC WORLDWIDE IECEx (International Electrotechnical Commission) Ex, d, [ia], IIC, T5 Ex Standard Typical Example of Equipment Marking IEC & CEC Sec. 18 NEC 505 Class I, Zone 1, AEx, d, [ia], IIC, T5 NEC 500 Class 1, Div. 1 NEC 500 Class 1, Div 2 NEC 505 Class 1, Zone 1 NEC 505 Class 1, Zone 2 NEC AEx NEC AEx NEC AEx IEC Zone 1 IEC Zone 2 IEC Ex OK for use in NEC 505 Class 1, Zone 1 & 2 OK for use in NEC 505 Class 1, Zone 2 NOT OK for use in NEC 500 Class 1, Div. 1 OK for use in NEC 500 Class 1, Div. 2 OK for use in NEC Zone 0, 1 2 as marked Not suitable for NEC 500 Class 1, Div. 1 Not suitable for NEC 500 Class 1, Div. 2 Not suitable for any NEC 500 areas Not suitable for any NEC 500 areas Not suitable for any NEC / CEC areas Equipment Certified for use in: Use Appropriately Equipment Certified for Use AS/NZS Maximum Surface Temp. 450˚ C (842˚F) 300˚ C (572˚F) 280˚ C (536˚F) 260˚ C (500˚F) 230˚ C (446˚F) 215˚ C (419˚F) 200˚ C (392˚F) T1 T2 T2A T2B T2C T2D T3 T Class 180˚ C (365˚F) 165˚ C (329˚F) 160˚ C (320˚F) 135˚ C (275˚F) 120˚ C (248˚F) 100˚ C (212˚F) 85˚ C (185˚F) T3A T3B T3C T4 T4A T5 T6 North American Ex standards in both the US and Canada follow two different approaches; the traditional ‘Class, Division’ method under NEC 500 (US) / CEC Annex J (Canada) and the new, ‘Internation- al Zoning System’ under NEC 505 (US) / CEC Section 18 (Canada). • Maximum Surface Temp. T Class Flammable Atmosphere is not likely to occur in normal operation Maximum Surface Temp. 450˚ C 300˚ C 200˚ C 135˚ C 100˚ C 85˚ C T1 T2 T3 T4 T5 T6 T Class ˚ C ˚ F 842˚ F 572˚ F 392˚ F 275˚ F 212˚ F 185˚ F Maximum Surface Temp. 450˚ C 300˚ C 200˚ C 135˚ C 100˚ C 85˚ C T1 T2 T3 T4 T5 T6 T Class ˚ C ˚ F 842˚ F 572˚ F 392˚ F 275˚ F 212˚ F 185˚ F Maximum Surface Temp. 450˚ C 300˚ C 200˚ C 135˚ C 100˚ C 85˚ C T1 T2 T3 T4 T5 T6 T Class ˚ C ˚ F 842˚ F 572˚ F 392˚ F 275˚ F 212˚ F 185˚ F 1.2 European Classification (CENELEC) 1.4 IEC Classification (NEC 505, CEC Section 18) 2.1 North American Explosion Groups (NEC 500 / CEC Annex J) 2.2 European Explosion Groups (CENELEC) 2.4 IEC Explosion Groups (NEC 505, CEC Sec. 18) 3.1 North American Temperature Classification (NEC 500 / CEC Annex J) 3.2 European Temperature Classification (CENELEC) 3.4 IEC Temperature Classification 4.1 North American Equipment Marking (NEC 500 / CEC Annex J) 4.2 European Equipment Marking (CENELEC) 4.4 IEC Equipment Marking (IEC, NEC 505, CEC Sec. 18) 1.3 Australian Classification (IEC) 4.3 Australian Equipment Marking 3.3 Australian Temperature Classifications 2.3 Australian Explosion Groups Hazardous locations are defined as areas where fire or explosion hazards may exist due to the presence of flammable gases or vapours, liquids or dusts. Worldwide, differing Ex standards use Hazardous area classifications to classify environments dependant on the frequency and persistence of a potentially explosive atmosphere occurring. • NEC ® 505 ZONE 0 ZONE 1 ZONE 2 NEC ® 500 *DIVISION 1 *DIVISION 1 *DIVISION 2 ATEX 1999/92/EC enforces hazardous area classification of work places into zones depending on the frequency and time that an explosive atmosphere is present. • 2.0 Explosion Groups Explosion groups are designated to classified hazardous areas to identify the ignition related properties of an explosive atmosphere. Worldwide, there are a number of different systems in place. The traditional North American ‘Class, Division’ system uses a different system to that used under ATEX in Europe and by the IEC, altering the way in which equipment manufactures build and mark certified Ex equipment. • 3.0 Temperature Classifications 4.0 Equipment Marking / Certification Explosion Proof equipment should be supplied with certified documentation and be clearly marked, displaying the measures the equipment has undergone to operate in classified hazardous areas. Throughout the world, differing country-specific standards impose different equipment marking methods, so it is important to understand how they compare. • protecting people, their investment and our environment Pyroban Ltd UK Endeavour Works Dolphin Road, Shoreham-by-Sea West Sussex, BN43 6QG, UK 1.0 Hazardous-Area Classification Flammable Atmosphere Present Continuously Ex Standard Typical Example of Equipment Marking NEC 500 / CEC Annex J CLASS 1, DIVISION 1, GROUPS A, B, C, D, T5 1.1 North American Classification ATEX 94/9/EC ( = CE Conformity Marking, = EU Explosion-Protection Marking, II = Equipment Groups [I = for mines, II = for other than mines], [2 = Equipment Category, G = Type of Ex Atmosphere; G (Gas), D (Dust)], Ex = Explosion Protected according to CENELEC standards, de = Protection Method, [II = Apparatus Group, C = Gas Group], T5 = Temperature Class 5.0 Protection Concepts, Methods & Standards In comparison to the traditional North American standards, ATEX classifies atmospheres containing flammable gases / vapours as Group II hazardous areas. • Group A Group B Group C Group Type Atmospheres containing... Acetone, Methane & similar gases Acetaldehyde, Ethylene & similar gases Acetylene, Hydrogen, & similar gases Group IIA gases represent gases most difficult to ignite while Group IIC represents gases easiest to ignite These groups are defined under EN60079 • NEC 500 / CEC Annex J (Class 1 = Hazard Class, Division 1 = Area Classification, Groups A, B, C, D = Permitted gas groups, T5 = Equipment Temperature Class) Flammable Atmosphere is likely to occur in normal operation Hazardous area classification should be carried out as an integral part of the risk assessment to identify areas where control over ignition sources is needed. • Australia has also implemented the IEC’s International Zoning System. • For further information on IEC hazardous classifications, see: IEC 60079-10 - Electrical Apparatus for Explosive Atmospheres, Classification of Hazardous Areas. • Group A Group B Group C Group Type Atmospheres containing... Acetone, Methane & similar gases Acetaldehyde, Ethylene & similar gases Acetylene, Hydrogen, & similar gases The IEC’s apparatus grouping system has been adopted by the ATEX directives in Europe and throughout the world, including the US (NEC 505) Canada (CEC Sec. 18) and Australia. The groups below, assigned to gases and vapours are categorised as Group II locations, as used in Europe. • • Special precautions need to be taken in hazardous areas to prevent equipment becoming a source of ignition. • Group IIA gases are similar to the NEC Group D gases. Group IIB are similar to NEC Group C while IEC Group IIC gases are similar to NEC group A & B. Temperature classes are assigned to indicate the safe working limit of the gases and vapours that could be present in a hazardous area. Equipment and apparatus working in a hazardous area must be designed / modified to the assigned T- Class to ensure surface temperatures do not exceed the ignition temperature of hazardous gases and vapours. • IEC & CEC Sec. 18: (Ex = Explosion-Protected, d = Type of Protection, [ia] = I.S Output, II = Group, C = Gas Group, T5 = Temperature Class Ex Standard Typical Example of Equipment Marking AS/NZS2381 Ex, de, IIC, T5 AS/NZS2381: Ex = Explosion-Protected, de = Protection technique, II = Apparatus Group, C = Gas Group, T5 = Temperature Class Electrical equipment used in a hazardous area must be certified to the IEC or Australian standards via an acceptable certification scheme. Acceptable schemes include IECEx, ANZEx and AUSEx. • Other equipment (e.g. ATEX, FM, UL) can usually be used if the legal owner justifies and accepts their use and an assessment is made as to the equivalence in safety of the equipment compared to IECEx / ANZEx or AUSEx equipment • Australia has also adopted the IEC methods of temperature classification. • The traditional North American ‘Class, Division’ system uses a unique temperature classification system to that adopted under the IEC. • ATEX has adopted the IEC’s methods of temperature classification, appointing a more generalised classification to a range of temperatures rather than the North American approach, using a number of further T-Classes. • The IEC’s new international approach has been adopted by many nations and Ex standards. For more information on IEC temperature classification, see: IEC 60079-20 • • Australia has adopted the IEC methods of classifying explosion groups. • Group A Group B Group C Group Type Atmospheres containing... Acetone, Methane & similar gases Acetaldehyde, Ethylene & similar gases Acetylene, Hydrogen, & similar gases Hazardous areas with gas or vapours present are designated Group II locations and the gases which make up the atmosphere are sub-categorised under the IEC’s three groups, A, B and C. • For more information on the Australian IEC’s gas grouping system, see: AS/NZS2430.3.4 ATEX Equipment Marking: • NEC 500 / CEC Annex J Equipment Marking: • Tel: +44 (0) 1273 466200 Fax: +44 (0) 1273 465313 e.mail: [email protected] Web: www.pyroban.com IEC Equipment Marking: • NEC 505: (Class I = Permitted Class, Zone 1 = Permitted Zone, AEx = American National Standard, d = Type of Protection, [ia] = I.S Output, II = Group, C = Gas Group, T5 = Temperature Class 5.1 Equipment Certified for Use Within Europe, the ATEX directives are imposed as a minimum requirement for Ex legislation. • For more information, visit www.pyroban.com/information-faq.html • For further information on the Australian IEC hazardous classification system, see: AS/NZS60079.10 (NB. This standard has replaced the formally, AS2430.1) • Flammable Atmosphere is not likely to occur in normal operation ATEX 1999/92/EC Flammable Atmosphere is likely to occur in normal operation Flammable Atmosphere Present Continuously ZONE 0 ZONE 1 ZONE 2 The IEC’s International Zoning System has become increasingly accepted worldwide. Although the IEC’s system aims to create a standardised approach to Explosion Protection, users and manufactures should be aware that many nations such as the US have incorporated a number of country- specific deviations in order to comply to current wiring methods under the NEC. • • For more information, visit www.pyroban.com/aus • Different country-specific Ex standards have appointed different temperature classification systems so it important to ensure your Ex equipment is modified to the correct level of protection. • CEC Section 18 ZONE 0 ZONE 1 ZONE 2 CEC Annex J *DIVISION 1 *DIVISION 1 *DIVISION 2 Flammable Atmosphere is not likely to occur in normal operation Australia Flammable Atmosphere is likely to occur in normal operation Flammable Atmosphere Present Continuously ZONE 0 ZONE 1 ZONE 2 Flammable Atmosphere is not likely to occur in normal operation IEC Flammable Atmosphere is likely to occur in normal operation Flammable Atmosphere Present Continuously ZONE 0 ZONE 1 ZONE 2 Protection Method Id. Letter Type of Protection NEC 500 / CEC Annex J Permitted Division IEC / CENELEC Permitted Zone Mode of Function Flameproof Intrinsic Safety Intrinsic Safety Pressurisation Increased Safety Oil Immersion Encapsulation Type ‘n’ Protection * Ventilation d ia ib p e o m n v Enclosure contains internal explosion I.S. circuits are unable to cause ignition I.S. circuits are unable to cause ignition Protection by over pressured enclosure Electric sparks & high temp. possibilities eliminated Protection by Immersion Encapsulated apparatus Non-Sparking apparatus Protection by Ventilation Explosion is Contained Sparks are not ignition capable (Safe 2 faults) Sparks are not ignition capable (Safe 1 faults) Flammable atmosphere is eliminated Source of ignition eliminated Flammable atmosphere is eliminated Flammable atmosphere is eliminated n Protection includes several methods of ignition protection Flammable atmosphere eliminated Division 2 Division 1 or 2 Division 2 Division 1 or 2 Division 2 Division 1 or 2 Division 2 Division 2 -------- Zone 1 or 2 Zone 0, 1 or 2 Zone 1 or 2 Zone 1 or 2 Zone 1 or 2 Zone 1 or 2 Zone 1 or 2 Zone 2 ----- IEC IEC 60079-1 IEC 60079-11 IEC 60079-11 IEC 60079-2 IEC 60079-7 IEC 60079-6 IEC 60079-18 IEC 60079-15 -------- CENELEC EN 60079-1 EN 60079-11 EN 60079-11 EN 60079-2 EN 60079-7 EN 60079-6 EN 60079-18 EN 60079-15 -------- CSA (IEC) AS/NZS60079-1 / AS2380.2 AS/NZS60079-11 / AS2380.7 AS/NZS60079-11 / AS2380.7 AS/NZS60079-2 / AS2380.4 AS/NZS60079-7 / AS2380.6 AS/NZS60079-6 AS/NZS60079-18 AS/NZS60079-15 AS 1482 NEC 500 AS/NZS FM 3618 FM3610 FM3610 FM 3620 FM 3619 FM 3621 FM 3614 ------- -------- CSA E60079-1 CSA E60079-11 CSA E60079-11 CSA E60079-2 CSA E60079-7 CSA E60079-6 CSA E60079-18 CSA E60079-15 -------- NEC 505 ISA 60079-1 ISA 60079-11 ISA 60079-11 ISA 60079-2 ISA 60079-7 ISA 60079-6 ISA 60079-18 ISA 60079-15 -------- CSA (Annex J) CSA C22.2 No. 30 CSA C22.2 No. 157 CSA C22.2 No. 157 CSA TIL. E13 A -------- -------- -------- CSA C22.2 No. 213 -------- * Only recognised in Australia