the inside of tank truck or the interior of a dust filter). Zone 0, 1, and 2 locations shall include those specified in 505.5 (B) (1), (B) (2), and (B) (3). THE CURRENT STANDARD . A60 Figures show that appr. A: No. All emergency versions, whether Zone 1 or Zone 2 can also be easily visually identified by their red end cap, encapsulating the emergency battery back-up. The NEMA enclosure rating or IP code may also be indicated, but it is usually independent of the Classified Area suitability. taper per foot. So the following conditions must be met for an explosion to occur: Represented by the following explosion triangle. February 2021 Informational Note No. Zones 1 or 2. Zone 2 Explosive Mixtures not likely to occur /occur short duration in normal operation (lt10 Hrs/ Yr). Equipment that is safe for the location shall be of a type and design that the employer demonstrates will provide protection from the hazards arising from the combustibility and flammability of vapors, liquids, gases, dusts, or fibers involved. Zone 0, 1 2 . In the US, the independent National Fire Protection Association (NFPA) publishes several relevant standards, and they are often adopted by government agencies. Both external and internal temperatures are taken into consideration. It may exist because of repair, maintenance operations, or leakage. The equipment group . Electric equipment depending on the protection techniques described by paragraph (g)(3)(i) of this section may not be suitable for use at temperatures lower than -20 C (-4 F) unless they are approved for use at lower temperatures. ". The specific hazardous materials within each group and their automatic ignition temperatures can be found in Article 500 of the National Electrical Code and in NFPA 497. National Electric Code 2020 edition National Fire Protection Association. Hazardous area equipment is categorized into category-1 for Zone 0 or Zone 20, category-2 for Zone 1 or Zone 21, and category-3 for Zone 2 or Zone 22. Locations are thus classified by type and risk of release of gas, vapor, or dust. This paper will discuss and review the current approaches and solutions of dealing with these HSE concerns, especially with the involvement of hazardous and potentially flammable and explosive chemicals. Accommodation Cabin Classification of Hazardous Areas 0 100 200 300 400 500 600 T1 >450C T2 >300C 450C T3 >200C 300C T4 >135C 200C . The most standards and codes of practise for Hazardous Area Classification describe typical installations and work environments and their hazardous areas. January 2023 Electronic equipment, including lighting, needs to be purpose designed for use in hazardous areas to prevent a spark occurring and igniting any flammable substances. An area where combustible dusts or ignitable fibers and flyings are present continuously or for long periods of time. A light switch may cause a small, harmless spark when switched on or off. THE PRODUCTS YOU NEED, Electrical equipment installation in atmosphere with flammable gases or vapors, flammable liquids, combustible dusts, ignitable fibers or flyings represents a risk for fire and explosion. Category 1 equipment may be used in zone 0, zone 1 or zone 2 areas. There are four zones in the IEC classification system: Zone 0: An area in which an explosive atmosphere is present continuously or for long periods. Canada has a similar system with CSA Group standard C22.1, the Canadian Electrical Code, which defines area classification and installation principles. The equipment housing may be sealed to prevent entry of flammable gas or dust into the interior. Zones also have the added benefit of including the area classification with the zone description. This is presented by the Lower Explosion Limit (LEL) of a substance. Zone 2. This level of risk is represented by classifying the hazardous area as Zone 0, Zone 1 or Zone 2 (for gas, vapour and mist atmospheres) or Zone 21 or Zone 22 for dust atmospheres. If equipment is marked, for example, Ex e II T4 then it is suitable for all subgroups IIA, IIB and IIC. 2: This classification usually includes, (B) Special Occupancies, Zone 0, 1, and 2 Locations, Article 505 Special Occupancies, Zone 0, 1, and 2 Locations, (B) Special Occupancies, Class I, Zone 0, 1, and 2 Locations, National Electrical Code 2020 of Illinois, National Electrical Code 2017 of Illinois, Ignitible concentrations of flammable gases or vapors are present continuously, Ignitible concentrations of flammable gases or vapors are present for long periods of time, In which ignitible concentrations of flammable gases or vapors are likely to exist under normal operating conditions; or, In which ignitible concentrations of flammable gases or vapors may exist frequently because of repair or maintenance operations or because of leakage; or, In which ignitible concentrations of flammable gases or vapors are not likely to occur in normal operation and, if they do occur, will exist only for a short period; or, In which volatile flammable liquids, flammable gases, or flammable vapors are handled, processed, or used but in which the liquids, gases, or vapors normally are confined within closed containers of closed systems from which they can escape, only as a result of accidental rupture or breakdown of the containers or system, or as a result of the abnormal operation of the, In which ignitible concentrations of flammable gases or vapors normally are prevented by positive mechanical ventilation but which may become hazardous as a result of failure or abnormal operation of the ventilation. In this article we will look at what defines Zone 0, Zone 1 and Zone 2 hazardous area classifications and the considerations for specifying lighting into each area. Many items of EEx rated equipment will employ more than one method of protection in different components of the apparatus. The housing may be strong enough to contain and cool any combustion gases produced internally. Zone 0 is an area in which an explosive atmosphere is present continuously for long periods of time or will frequently occur. Area classification documentations are reviewed and updated to reflect process changes. Example - Hazardous Area Classification A room with a propane gas installation will typically be classified with the Class/Division system as: Class I, Division 2, Group D Zone system as: Zone 2, Group IIA Horizontal. Since the changes to the code, hazardous locations with gases or vapors (Class I) present can be reclassified as Zone 0, 1 or 2. Well recognized and clear IEC Standard IEC 60079-10-2:2015 Hazardous Area Classification for explosive dusts Significant influence on spending's for safety . Oxygen is required in high quantities and in combination with the flammable substance to produce an explosive atmosphere. 1: As a guide in determining when flammable gases or vapors are present continuously or for long periods of time, refer to ANSI/API RP 505-2018, Informational Note No. 15 4. API RP 505, Recommended Practice for Classification of Locations for Electrical Installations at Petroleum Facilities Classified as Class I, Zone 0, Zone 1, and Zone 2 (as incorporated by reference in 250.198). Quick Tips #124.1. 0,1 or 2: II B: I: 1 or 2: C: Acetone Benzene Butane Hexane . Area classification is not simply intended to identify hazardous areas on process plants where design has already been completed using only operational and economic factors as influence,. This is exactly defined as the limiting concentration of oxygen below which combustion is not possible, independent of the concentration of fuel. The inductance of the signal bell coils, combined with breaking of contacts by exposed metal surfaces, resulted in sparks, causing an explosion. National Electrical Code, NFPA 70, Chapter 5, Article 500, 29 CFR 1910 Subpart S, Electrical 1910.307, NFPA 497, "Classification of Gases, Vapors, and Dusts for Electrical Equipment in Hazardous Classified Locations", NFPA Handbook, "Electrical Installations in Hazardous Locations, " by P. J. Schram and M. W. Earley, NFPA 70E, Chapter 5, "Hazardous (Classified) Locations", ANSI/UL 913, "Intrinsically Safe Apparatus", NFPA 496, "Purged and Pressurized Enclosure for Electrical Equipment in Hazardous Locations. Many people have heard terms like Class I, Division 2, Group E, or ATEX zone 21 but many of our customers only know what certification they require with little understanding of what they mean, so we thought it would be appropriate to write a blog post to help customers understand the broader implications of these terms. Directly adjacent on the label one will find the mark of the listing agency. This level of risk is represented by classifying the hazardous area as Zone 0, Zone 1 or Zone 2 (for gas, vapour and mist atmospheres) or Zone 21 or Zone 22 for dust atmospheres. Whenever you are filling up your tank you are standing in a Zone 1 hazardous area. * Zone 1 a location in which explosive gas atmospheres are likely to occur during normal operation, or which is adjacent to a Zone 0 location. These areas are classified solely for the purpose of ensuring the safe and proper specification and installation of electrical/electronic equipment. [12], International Electrotechnical Commission, Occupational Safety and Health Administration, National Electrical Manufacturers Association, "Hazardous Area Classification and Control of Ignition Sources", "Hazardous (Classified) Locations NEC Articles 500 through 517", https://en.wikipedia.org/w/index.php?title=Electrical_equipment_in_hazardous_areas&oldid=1134828101, ignitable concentrations of combustible dust can exist, under normal conditions, ignitable concentrations of combustible dust are unlikely to exist normally, ignitable fibers, or materials producing combustible flyings, are handled, manufactured or used, easily ignitable fibers are stored or handled. This was accompanied by electrically-initiated explosions of flammable gas such as fire damp (methane) and suspended coal dust. December 2021 Division II Comprising of Area Same as Zone 2. The part codes for each SPARTAN variant also differ depending on the level of protection required. February 2022 This process is called hazardous area classification. Arcing electrical equipment in unclassified . June 2020 AddThis use cookies for handling links to social media. A: When comparing Divisions and Zones, Division 2 is equivalent to Zone 2, but Division 1 is equivalent to either Zone 0 or 1. Flour, wood/sawdust, plastic dust), IIC Conductive dusts (eg. area in which an explosive gas atmosphere is not likely to occur in normal operation, but, if it does occur, will exist for a short period only (less than 0,1% of the time), Window breakage, cracks plaster, light damage to buildings, Collapse of wood or asbestos siding of homes, Collapse of walls made of concrete blocks, Reinforced concrete structures severely damaged, Flames and hot gases (including hot particles), Mechanically generated impact, friction and abrasion, Stray electric currents, cathodic corrosion protection, Radio frequency (RF) electromagnetic waves from 10, Exothermic reactions, including self-ignition of dusts, EI 15 Energy Institute 15, mostly for on- and offshore oil and gas applications. June 2019 NEC has created an Americanized version of the IEC/CENELEC Zone system in a stand-alone article (Article 505). But first, we must consider what is likely to cause an explosion in the first place. NEC Div 1 Zone 1 Div 2 Zone 2Flammable during normal operation Most Safer Zone IEC Zone 0 DESRIPTIONHighly Flammable for long period DEFINITIONFlammable atmosphere present continuously (Typically 1000 hours / year). Zone 1 - Explosive atmospheres are likely to occur. Explosions can cause significant damage along with severe injury or worse loss of life. In recent years also the EPL is specified for several kinds of protection. This classification method provides a description of the hazardous material that may be present, and the probability that it is present, so that the appropriate equipment may be selected, and safe installation practices followed. >> For Gas/Vapor this would be Zone 0. In an industrial plant, such as a refinery or chemical plant, handling of large quantities of flammable liquids and gases creates a risk of exposure. SPARTANs Zone 1 part code begins SPX, Zone 2 SPZ and industrial products having a SPI prefix. Zone 0 Area The definition according to IEC60079-10-1 is "an area in which an explosive gas atmosphere is present continuously or for long periods or frequently". These generally give rise to areas classied as Zones 0, 1, and 2 respectively. * Zone 2 a . Hazardous areas are classified into zones based on an assessment of the frequency of the occurrence and duration of an explosive gas atmosphere, as follows: Zone 0: An area in which an. BATTERY ENERGY STORAGE SYSTEMBESS) (between 0,1 and 10% of the time). Only emails and answers are saved in our archive. These generally give rise to areas classied as Zones 0, 1, and 2 respectively. A hazardous area classification drawing (also known as an area classification drawing) outlines the classifications of areas where flammable liquids, gasses or vapors are handed, processed or stored. October 2018 lk) are places where fire or explosion hazards may exist. Equipment shall be marked to show the class, group, and operating temperature or temperature range, based on operation in a 40-degree C ambient, for which it is approved. This article covers the requirements for the, Informational Note No. January 2022 [1] NEC article 500 describes the NEC Division classification system, while articles 505 and 506 describe the NEC Zone classification system. As a result, all hazardous area equipment must be designed with hazardous area zone classifications in mind, as the zone governs the level of protection and precaution required. In some cases, the hazardous atmosphere is present all the time, or for long periods. Equipment can be designed or modified for safe operation in hazardous locations. As world trade becomes more globalized, international standards are slowly converging, so that a wider range of acceptable techniques can be approved by national regulatory agencies. Atmospheres containing ethylene, propylene oxide, ethylene oxide, butadiene, cyclopropane, ethyl ether, or gases and vapors of equivalent hazard. An explosion is a rapid expansion in volume associated with an extremely vigorous outward release of energy, usually with the generation of high temperatures and release of high-pressure gases (wikipedia (https://en.wikipedia.org/wiki/Explosion). . Hazardous areas are those defined as areas of potential explosion risk due to the presence of flammable gas or vapor. No long-term contract. A differentiation is made between gas Ex zones and dust Ex zones: Gas Ex zones are 0/1/2 and dust Ex zones are 20/21/22. Carbon monoxide, ether, hydrogen sulfide, . The key difference between Divisions and Zones relate to terminations. September 2018 Hazardous Area Classification, Gas Vapours and Dust Groups, Temperature Class | Simple Science Simple Science 8.81K subscribers Join Subscribe 28K views 2 years ago This video explains. 6: For further information on electrical systems for hazardous (classified), Informational Note No. This leads to a lot of the confusion in the global marketplace because certifying equipment to these different systems can be time consuming and expensive, so many companies may only certify to one or the other. It uses the familiar Class/Division system and adapts the IEC/CENELEC Zones into it while maintaining NEC wiring methods and . In Europe the label must show the CE mark and the code number of the certifying/notified body). These hazardous (classified) locations are assigned the following designations: For definitions of these locations, see 1910.399. Area ClassificationThe max surface temp. area in which an explosive gas atmosphere is likely to occur occasionally in normal operation. The groups also indicate how much energy is required to ignite the material by energy or thermal effects, with IIA requiring the most energy and IIC the least for zone system gas groups. Please read Google Privacy & Terms for more information about how you can control adserving and the information collected. It is created based on input from the Process Flow Diagrams, Piping & Instrumentation Diagrams and the Equipment Location Plan . This means that the electrical equipment is safe for use within these area by applying special protection strategies. When comparing Divisions and Zones, Division 2 is equivalent to Zone 2, but Division 1 is equivalent to either Zone 0 or 1. NFPA 70 NEC Classes, Divisions and Groups. Gas a. Some manufacturers claim "suitability" or "built-to" hazardous areas in their technical literature, but in effect lack the testing agency's certification and thus unacceptable for the AHJ (Authority Having Jurisdiction) to permit operation of the electrical installation/system. The flash point determines if an area needs to be classified. Such areas include a residence or office where the only risk of a release of explosive or flammable gas would be such things as the propellant in an aerosol spray. RP 505 is referred to as the zone system. For methane this is shown in the following figure. class correct, Motors, lighting, junction boxes, electronics, Equipment is very robust and components are made to a high quality, Equipment components are completely submerged in oil, Equipment components are completely covered with a layer of sand, powder or quartz, Equipment components of the equipment are usually encased in a resin type material. The information contained in this article is intended for general information purposes only and is based on information available as of the initial date of publication. 2) MIC (Minimum Igniting Current) Ratio - The ratio of the minimum current required from an inductive spark discharge to ignite the most easily ignitable mixture of a gas or vapor, divided by the minimum current required from an inductive spark discharge to ignite methane under the same test conditions. For equipment with metric threaded entries, such entries shall be identified as being metric, or listed adaptors to permit connection to conduit of NPT-threaded fittings shall be provided with the equipment. Flammable atmosphere expected to be present inside the storage tank continuously, hence it has been classified as zone 0. Also known as non-hazardous or ordinary locations, these locations are determined to be neither Class I, Division 1 or Division 2; Zone 0, Zone 1 or Zone 2; or any combination thereof. You can target the Engineering ToolBox by using AdWords Managed Placements. The more hazardous the area to more safety measures have to be taken in order to prevent equipment becoming an effective source of ignition. The surface of a high pressure steam pipe may be above the autoignition temperature of some fuel-air mixtures. Engineering ToolBox - Resources, Tools and Basic Information for Engineering and Design of Technical Applications! Hazardous classified locations are areas where the possibility of fire or explosion hazards may exist under normal or abnormal conditions because of the presence of flammable, combustible or ignitable gases, vapors, liquids, dust, or fibers/flyings. Recommendat ions. Areas with possible fire or explosion risks due to explosive atmospheres and/or mixtures - are called hazardous (or classified) locations or areas. Zone 1 . Wide known is that al electrical equipment within hazardous areas must be Ex certified for use in the appropriate hazardous area (zone or class/division). Is intended for us in Zone 2 (gases) or Zone 22 (dusts). 3: For further information on the classification of, Informational Note No. These are typically process areas where gases are more likely to be present. Offshore Workshop Container Since this fuel can only combust in the presence of oxygen, enough oxygen must be available for the rapid combustion to take place. . Equipment is pressurised to a positive pressure relative to the surrounding atmosphere with air or an inert gas, thus the surrounding ignitable atmosphere can not come in contact with energized parts of the apparatus. The temperature marking may not exceed the ignition temperature of the specific gas or vapor to be encountered. Zone 2 is a place in which an explosive atmosphere is not likely to occur in normal operation but, if it does occur, will persist for a short period only. December 2020 MCC Shelter Add standard and customized parametric components - like flange beams, lumbers, piping, stairs and more - to your Sketchup model with the Engineering ToolBox - SketchUp Extension - enabled for use with the amazing, fun and free SketchUp Make and SketchUp Pro .Add the Engineering ToolBox extension to your SketchUp from the SketchUp Pro Sketchup Extension Warehouse! Explosion-proofing designs equipment to contain ignition hazards, prevent entry of hazardous substances, and, contain any fire or explosion that could occur. These areas only become hazardous in case of an accident or some unusual operating condition. . Standards and regulations exist to identify such locations, classify the hazards, and design equipment for safe use in such locations. less than 0.45 mm or MIC ratio is less than 0.40. Intrinsic safety -- This protection technique is permitted for equipment in the Class I, Zone 0 or Zone 1 locations for which it is approved. of the autoignition temperature of the hazardous atmosphere. In the US, the National Electrical Manufacturers Association (NEMA) defines standards for enclosure types for a variety of applications. Type of protection "n" is further subdivided into nA, nC, and nR. NFPA 70 NEC Articles 500 through 503 cover the requirements for electrical/electronic equipment and wiring for all voltages in Class I, Divisions 1 and 2; Class II, Divisions 1 and 2; and Class III, Divisions 1 and 2 locations. .14 . For liquids, gases and vapours: Zone 0, Zone 1 and Zone 2. Atmospheres containing acetylene, hydrogen, carbon disulphide or gases and vapors of equivalent hazard. The Hazardous Area Classification presents in this guide is based on the following items as reference: API: API RP 505 Recommended Practice for Classification of Locations for Electrical. An oversimplification of this example is shown in Table 1. Ignitable concentrations of flammable gases or vapors which are likely to occur under normal operating conditions. Equipment approved for Class I, Division 1 or Class 1, Division 2 shall, in addition to being marked in accordance with (c)(2)(ii), be marked with the following: Class I, Zone 1 or Class I, Zone 2 (as applicable); Applicable gas classification groups; and. . International Electrotechnical Committee (IEC) Hazardous Area Classification. So yes, it is important to choose the right model and always wonder what am I assessing?. Table 1. >> NEC: Class I, Division 2, Group D. | IEC: Zone 2, Group II. March 2021 That flammable gas or vapor . Group II is for explosive gases (Zone 0, 1 and 2) and Group III is for explosive dusts (Zone 20, 21 and 22). For example, a Class 1, Div 1 area where Group A may be present would be defined as an area where flammable gases or vapors may be present under normal operating conditions. Group II is for explosive gases (Zone 0, 1 and 2) and Group III is for explosive dusts (Zone 20, 21 and 22). WELDING INSPECTION NFPA 70 NEC uses the familiar Class/Division system and has added an Americanized version of the International Electrochemical Commissions (IEC) IEC Zone system which maintains the NEC wiring methods and protection techniques. Raytec do not currently offer any lighting solutions for Zone 0. February 2023 Some equipment in Division 2 areas do not require a specific label, such as standard 3 phase induction motors that do not contain normally arcing components. This level of risk is represented by classifying the hazardous area as Zone 0, Zone 1 or Zone 2 (for gas, vapour and mist atmospheres) or Zone 21 or Zone 22 for dust atmospheres. A special standard for instrumentation is IEC/EN 60079-27, describing requirements for Fieldbus Intrinsically Safe Concept (FISCO) (zone 0, 1 or 2) (This special standard has been withdrawn, and has been partially replaced by: IEC/EN60079-11:2011 and IEC/EN60079-25:2010)[1], A special standard for instrumentation is IEC/EN 60079-27, describing requirements for Fieldbus Non-Incendive Concept (FNICO) (zone 2) (This special standard has been withdrawn, and has been partially replaced by: IEC/EN60079-11:2011 and IEC/EN60079-25:2010)[9]. April 2022 Zone 0/20: An area in which an explosive atmosphere is present continuously or for long periods or frequently. In Northerm America, instead of the zone classification system, the Class/Division system is used. Equipment approved for use in Class I hazardous locations cannot be used in Class II hazardous locations. The following Equipment Groups and Categories are applicable: Equipment in this category is only intended for use in the underground areas of mines, as well as those areas of surface installations of such mines endangered by firedamp and/or combustible dusts. 1. In Europe and the rest of the world - but also more and more in North America - the Zone system is used. There are three necessary components for an explosion to occur; This needs to be present in a relatively high quantity to produce an explosive mixture (e.g. When the concentration of methane is beneath the LEL, an explosion cannot occur, even when an ignition source is present. . 1) MESG (Maximum Experimental Safe Gap) - The maximum clearance between two parallel metal surfaces that has been found under specified test conditions to prevent an explosion in a test chamber from being propagated to a secondary chamber containing the same gas or vapor at the same concentration. Shown below is a summary of the applicable NEC Articles to reference to ensure the proper requirements are applied. All equipment in Division 1 areas must have an approval label, but certain materials, such as rigid metallic conduit, does not have a specific label indicating the Cl./Div.1 suitability and their listing as approved method of installation in the NEC serves as the permission. But when we take a closer look at the graph and table, we can conclude that any explosion, can easily lead to severe damage. December 2013, All As to the classification, they are the same. For Zone 1 applications, Pyroban uses . Within a working area or installation an ignition can be created by many factors. The above groups are formed in order of how explosive the material would be if it was ignited, with IIC being the most explosive zone system gas group and IIA being the least. In many industrial, commercial, and scientific settings, the presence of such an atmosphere is a common, or at least commonly possible, occurrence. ADNOC August 2021 Equipment that is listed for a Zone 1 location may be installed in a Zone 2 location of the same gas or vapor. . The four steps involved in hazardous area classification are: Determine the type of hazard or "class" that might be presentcombustible gas (Class I), combustible dust (Class II), or fibers (Class III). Examples are: production facilities in the food industry, chemical plants, oil & gas, and the pharmaceutical industry etc. In effect it is any method which can be shown to have the required degree of safety in use.