February 2022 Examples are: production facilities in the food industry, chemical plants, oil & gas, and the pharmaceutical industry etc. BATTERY ENERGY STORAGE SYSTEMBESS) An area where combustible dusts or ignitable fibers and flyings are present continuously or for long periods of time. Each chemical gas or vapour used in industry is classified into a gas group. In order to understand hazardous area classification it is important to understand which factors contribute to the occurrence of an explosion. Fundamentally, for an explosion to take place, flammable or explosive gases, vapours, mists or dusts will be present. The classification process requires the participation of operations, maintenance, safety, electrical and instrumentation professionals; and the use of process diagrams, material flows, safety data sheets, and other pertinent documents. There are two systems in place, including the traditional North American Division system as well as the alternative Zone system. The substance referred to by classhas a high probability of producing an explosive or ignitable mixture due to it being present continuously, intermittently, or periodically or fromthe equipment itself under normal operating conditions. Within the European Union, these are defined by IEC/EN standards (IEC/EN 60079-10-1 or 2) as directed by ATEX. Q: Can equipment approved for a Class I hazardous location be used in a Class II hazardous location? 29 CFR 1910.307 Hazardous (classified) Locations So the flammable range of a substance is the concentration of gases and vapors in air between the Lower Explosion Limit and the Upper Explosion Limit. Zone 0/20: An area in which an explosive atmosphere is present continuously or for long periods or frequently. of the autoignition temperature of the hazardous atmosphere. The zone classification for gases is divided into three zones, namely Zone 0, Zone 1 and Zone 2 and for dusts Zone 20, Zone 21 and Zone 22. Identifying Zone 0, Zone 1, and Zone 2 Hazardous Areas. When equipment must be placed in a hazardous location, it can be designed to reduce the risk of fire or explosion. All areas in the facility that are not Zone 0, Zone 1, or Zone 2 are considered unclassified. LIFTING TEST The simplest is to minimize the amount of electrical equipment installed in a hazardous location, either by keeping the equipment out of the area altogether, or by making the area less hazardous (for example, by process changes, or ventilation with clean air). 29 CFR 1910.399 Definitions Applicable to Subpart S In 29 CFR 1910.307(c)(2)(ii), OSHA requires all equipment used in a hazardous location to be marked with the class, group and operating temperature or temperature range for which it is approved. Atmospheres containing ethylene, propylene oxide, ethylene oxide, butadiene, cyclopropane, ethyl ether, or gases and vapors of equivalent hazard. 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. The definition of Zone 2 is a hazardous area classified as an atmosphere where a mixture of air and flammable substances in the form of gas, vapour or mist is not likely to occur in normal operation, but if it does occur, will persist for a short period only. Zone 0, 1, and 2 locations shall include those specified in 505.5 (B) (1), (B) (2), and (B) (3). These are typically process areas where gases are more likely to be present. As mentioned, the first important step of achieving a safe work environment in relation to explosion safety is to identify and classify those areas, where a concentration of flammable gases or vapors within the flammable range can be present. Groups E, F, and G are for dusts and flyings (Class II or III). The upper explosion limit of a substance is the highest concentration (in volume percentages for gases and liquids) of a gas or a vapor in air capable of producing a flash of fire in the presence of an ignition source. 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). ethanol, methane or hydrogen. Temporary Refuge The equipment group . These ways of protection are specified in detail within several IEC standards (IEC 60079 series) for electrical equipment. The last condition for an explosion is the presence of an effective ignition source in the direct contact with the fuel/air mixture. 1: The term "Class I" was originally included as a prefix to, Informational Note No. This rapid expansion of volume is caused by the combustion of a fuel, like e.g. Protecting against fire and explosion is of interest for both personnel safety as well as reliability reasons. Hazardous Environment Classifications: NEC vs IEC, IEC (International Electrotechnical Commission), Group E Metal dusts (eg. D8.1.3 Hazardous areas are subdivided into Zones 0,1 or 2, the definitions of each cate-gory being as follows: Zone 0 an area in which an explosive gas-air mixture is continuously present or present for long periods. There are three zones for gas: Zone 0, Zone 1 and Zone 2. This can be achieved by blanketing with nitrogen or carbondioxide. | For Dust this would be Zone 21. 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. (between 0,1 and 10% of the time). Classification of Hazardous Areas 0 100 200 300 400 500 600 T1 >450C T2 >300C 450C T3 >200C 300C T4 >135C 200C . Zones. A: Yes. A Zone defines the general nature - if it is a gas or dust - and the probability of hazardous material being present in an ignitable concentration in the surrounding atmosphere. When working in or specifying equipment for use in hazardous environments, we see a lot of confusion in the industry regarding the different certifications and requirements. Hazardous Area Classification is a study, in which is assessed, at witch locations of a plant, factory or company, high concentrations of flammable gases are present or can be released, in order to create an explosion hazard. 6: For further information on electrical systems for hazardous (classified), Informational Note No. You will find these zones at the manifold of a tank truck or the interior of a silo. The plan may contain the list of chemicals with their group and temperature rating. Equipment in this category is intended for use in areas in which explosive atmospheres caused by gases, vapours, mists or air/dust mixtures are likely to occur occasionally. Methane has a LEL of 4,4 vol%. WELDING INSPECTION Definition of hazardous area zones (AS/NZS 60079.10): Zone 0 Atmosphere containing carbonaceous dusts, Atmosphere containing combustible dust not included in Group E & F - such as. Class II, Div 2 Class III, Div 1 nR 3G Zone 2 Gc Class III, Div 2 Pressurised Room px 60079-13 2G Zone 1 Gb Zone 21 Db 2D Pressurised Room FM3611 NFPA 496 Class I, Div 1 Class I, Div 2 Class II, Div 1 Class II, Div 2 py 2G Zone 1 Gb pz 3G Zone 2 Gc Zone 22 Dc 3D pv Non-hazardous Gb/GC Optical Radiation op sh 60079-28 1G Zone 0 Ga Zone 20 Da 1D . The Occupational Safety and Health Administration (OSHA) has adopted these hazardous classifications and all except Groups are defined in 29 Code of Federal Register (CFR) 1910.399. September 2019 Examples are: In another blog we, will explain how to perform Hazardous Area Classification according to the Standard EN-IEC 60079-10-1. Groups A, B, C, and D are for gases (Class I only). Well recognized and clear IEC Standard IEC 60079-10-2:2015 Hazardous Area Classification for explosive dusts Significant influence on spending's for safety . lk) are places where fire or explosion hazards may exist. WATER TIGHTNESS 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. 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. Safe for the hazardous (classified) location. Informational Note No. Ex s is a coding referenced in IEC 60079-0. Zone 0 describes an area in which a combustible gas will be present continuously while zone 20 describes an area in which combustible dust will be present continuously (the '2' in 'zone 20' indicates dust as opposed to gas). The housing may be strong enough to contain and cool any combustion gases produced internally. Subscribe 6.9K views 2 years ago Oil and Gas Zone Classifications: A) Hazardous Area Classification It's cable reimagined No DVR space limits. Area (mm2) CFD BS EN 60079-10-1:2009 1 5.0 5.0 0.0936 12.3 - 61.7 2 5.0 2.5 0.0326 6.17 - 30.8 41 gas explosions per year occur within the UK and app. The definition of the hazardous area zones represent the likelihood of hazardous gas, dust or other hazards being present in a working area. 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. Although OSHA does not provide a definition of group classifications in 29 CFR 1910.307 or 399 they do provide a note under 29 CFR 1910.307(c)(1) that states: NFPA 70, the National Electrical Code, lists or defines hazardous gases, vapors, and dusts by Groups characterized by their ignitable or combustible properties. To meet OSHAs marking requirement, the marking must include the hazardous group the equipment is approved to operate in. Standards for electrical installations have been established and are governed by a variety of organizations throughout the world to ensure safe electrical systems in hazardous locations. Methane has a UEL of 17 vol%, which means when the concentration of methane in air is above the 17 vol% an explosion cannot occur even when an ignition source is present. Whenever you are filling up your tank you are standing in a Zone 1 hazardous area. The CE mark is complemented with the Ex mark: A yellow-filled hexagon with the Greek letters (epsilon chi), followed by the Group, Category, and, if Group II, G or D (gas or dust). Zone 0, 1, and 2 locations are those in which flammable gases or vapors are or may be present in the air in quantities sufficient to produce explosive or ignitible mixtures. Outside of the United States, the IEC uses two different classifications: Gas & Vapor (Zones 0, 1, or 2) Dust (Zones 20, 21, or 22) Step 2: The next step is to determine how often the hazardous substance (s) is/are present. Both external and internal temperatures are taken into consideration. It may exist because of repair, maintenance operations, or leakage. August 2018 In the United States, the hazardous location classification system is defined by the National Fire Protection Association (NFPA) 70, National Electric Code(NEC). For equipment provided with threaded entries for NPT threaded conduit or fittings, listed conduit, conduit fittings, or cable fittings shall be used. 2: For Group IIIC combustible dusts or metal combustible fibers/flyings, there shall only be Zone 20 or 21 locations. 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. If you require more information on the different variants in the SPARTAN range, or you would like to discuss your application in more detail, you can call us on +44 (0) 1670 520055 or send an email to sales@raytecled.comwhere we will happily answer any questions you have. Arc-producing elements can be isolated from the atmosphere, by encapsulation in, Heat-producing elements can be designed to limit their maximum temperature below the. Those guidelines address electric wiring, equipment, and systems installed in hazardous (classified) locations and contain specific provisions for the following: wiring methods, wiring connections; conductor insulation, flexible cords, sealing and drainage, transformers, capacitors, switches, circuit breakers, fuses, motor controllers, receptacles, attachment plugs, meters, relays, instruments, resistors, generators, motors, lighting fixtures, storage battery charging equipment, electric cranes, electric hoists and similar equipment, utilization equipment, signaling systems, alarm systems, remote control systems, local loud speaker and communication systems, ventilation piping, live parts, lightning surge protection, and grounding. In the US, the independent National Fire Protection Association (NFPA) publishes several relevant standards, and they are often adopted by government agencies. MCC Shelter With the advent of electric power, electricity was introduced into coal mines for signaling, illumination, and motors. 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. For specific industries, the specific codes for that industry are important to use. Equipment approved for use in Class I hazardous locations cannot be used in Class II hazardous locations. How to perform Hazardous Area Classification? No hidden fees. Area Classification. Unlike ATEX which uses numbers to define the safety "Category" of equipment, namely (1,2 3), the IEC continued to utilise the method used for defining the safe levels of intrinsic safety namely "a" for zone 0, "b" for zone 1 and "c" for zone 2 and apply this Equipment Level of Protection to all equipment for use in hazardous areas since 2009. Vertical. See Figure S-1 for an explanation of this marking. . Entire Vapour space of storage tank. When the concentration of methane is beneath the LEL, an explosion cannot occur, even when an ignition source is present. That flammable gas or vapor . The temperature marking may not exceed the ignition temperature of the specific gas or vapor to be encountered. No. September 2020 Area classification documentations are reviewed and updated to reflect process changes. The Class/Division/Group system is based on Article 500 of the National Electrical Code (NEC) where. For Zone 1 applications, Pyroban uses . A major safety concern in all workplaces is the occurrence of fires and explosions. There are two sets of Zones: Zones 0 thru 2 are used for gases, vapors, and mists, and Zones 20 thru 22 are . Quick Tips #124.1. Temporary Refuge (TR) Shelter Class I, Zone 0 or Zone 1 locations may not abut Class I, Division 1 or Division 2 locations. Substance properties are specific for the amount of fuel needed to get an explosion when all other conditions are met. Several protection strategies exist. Zone 0 is an area in which an explosive atmosphere is present continuously for long periods of time or will frequently occur. This page was last edited on 20 January 2023, at 22:32. Area's are divided into zones. All threaded conduit shall be threaded with an NPT (National (American) Standard Pipe Taper) standard conduit cutting die that provides -in. Increased safety "e" -- This protection technique is permitted for equipment in the Class I, Zone 1 locations for which it is approved. SEWAGE TREATMENT 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. November 2019 . >> For Gas Vapor this would be Zone 1. Zones 1 or 2. Photo 2. Zone 2 Explosive Mixtures not likely to occur /occur short duration in normal operation (lt10 Hrs/ Yr). Equipment is non-incendive or non-sparking. It is good to be aware of the fact that the mixture of flammable gas with oxygen has an optimum point where the combustion is most severe and leads to the highest explosion pressure. Sources of such hazards include gases, vapors, dust, fibers, and flyings, which are combustible or flammable. The Regulations define 3 zones that can exist within a hazardous area: Zone 0 - A place in which an explosive atmosphere is present continuously or for long periods. In the US, the National Electrical Manufacturers Association (NEMA) defines standards for enclosure types for a variety of applications. In North America the suitability of equipment for the specific hazardous area must be tested by a Nationally Recognized Testing Laboratory, such as UL, FM Global, CSA Group, or Intertek (ETL). Equipment should be tested to ensure that it does not exceed 80%[according to whom?] In this system, two bare wires were run along the length of a drift, and any miner desiring to signal the surface would momentarily touch the wires to each other or bridge the wires with a metal tool. coal and charcoal), Group G Nonconductive dusts (eg. 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. Class 1/Div 2 ATEX Zone 2 Computers. 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. December 2013, All 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. The two general approaches are: Several techniques of flame-proofing exist, and they are often used in combination: Equipment has flameproof gaps (max 0.006" (150m) propane/ethylene, 0.004" (100m) acetylene/hydrogen), Equipment can be installed in ANY housing provided to IP54.A 'Zener Barrier', opto-isolator or galvanic unit may be used to assist with certification. Empirical testing is done to determine parameters such as the maximum experimental safe gap (MESG), minimum igniting current (MIC) ratio, explosion pressure and time to peak pressure, spontaneous ignition temperature, and maximum rate of pressure rise. It is an Americanized version of the International Electrochemical Commissions (IEC) Zone system which maintains the NEC wiring methods and protection techniques. For dusts: Zone 20, Zone 21 and Zone 22. August 2022 THE CURRENT STANDARD . For methane this is shown in the following figure. Accommodation Cabin The inductance of the signal bell coils, combined with breaking of contacts by exposed metal surfaces, resulted in sparks, causing an explosion. Zone 0 is an area in which an explosive atmosphere is present continuously for long periods of time or will frequently occur. Which Standards to use for Hazardous Area Classification. October 2020 However, at low ambient temperatures, flammable concentrations of vapors may not exist in a location classified Class I, Zone 0, 1, or 2 at normal ambient temperature. It is obvious to use those standards within these industries. Much early equipment having Ex s protection was designed with encapsulation and this has now been incorporated into IEC 60079-18 [Ex m]. PROCESS OF CONTAINER 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. The prevention of explosions in working environments is in most countries regulated in national laws and directives. 14 4. Table 1. What are 'Dark Factories,' and Do They Really Exist? Zones compares to classes and divisions in the Class/Division system. September 2021 So the following conditions must be met for an explosion to occur: Represented by the following explosion triangle. A Zone 1 hazardous area is classified as a place in which an explosive atmosphere consisting of a mixture with air or flammable substances in the form of gas, vapour or mist is likely to occur in normal operation occasionally. Equipment shall be approved not only for the class of location, but also for the ignitable or combustible properties of the specific gas, vapor, dust, or fiber that will be present. The first thing to understand is that much like the metric vs imperial measuring systems, the United States uses its own methodology which differs from much of the world. If equipment has been approved for use in a Division 1 hazardous location, it can be used in a Division 2 hazardous location, providing it is in the same class and group. In many industrial, commercial, and scientific settings, the presence of such an atmosphere is a common, or at least commonly possible, occurrence. WHEN YOU NEED THEM. Area which are not devided into Atex zones, are called non-hazardous area's. Class / Division System In Northerm America, instead of the zone classification system, the Class/Division system is used.
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