Protecting against fire and explosion is of interest for both personnel safety as well as reliability reasons. Zone 1 . As a guide for Zone 0, this can be defined as over 1000 hours/year or >10% of the time. Employers may use the zone classification system as an alternative to the division classification system for electric and electronic equipment and wiring for all voltage in Class I, Zone 0, Zone 1, and Zone 2 hazardous (classified) locations where fire or explosion hazards may exist due to flammable gases, vapors, or liquids. But every hazardous area is different and each has specific requirements depending on the nature of the atmosphere and the elements that are present. Category 3 equipment may only be used in zone 2 areas. Area's are divided into zones. Under the "Zone" system, hazards are defined for gas as Zone 0, 1 or 2, with 0 as the highest hazard, and for dust as Zone 20, 21 or 22, with 20 as the . In an ordinary household this is of no concern, but if a flammable atmosphere is present, the arc might start an explosion. Each room, section, or area shall be considered individually in determining its classification. Classification of Hazardous Areas 0 100 200 300 400 500 600 T1 >450C T2 >300C 450C T3 >200C 300C T4 >135C 200C . An oversimplification of this example is shown in Table 1. 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. Controls can be fitted to detect dangerous concentrations of hazardous gas, or failure of countermeasures. Such properties include flame temperature, minimum ignition energy, upper and lower explosive limits, and molecular weight. In electrical and safety engineering hazardous locations HazLoc pronounced hazlk are places where fire or explosion hazards may exist. 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. The design of the equipment must ensure protection, even in the event of rare incidents relating to the equipment. There are two systems in place, including the traditional North American Division system as well as the alternative Zone system. 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. Please read AddThis Privacy for more information. We don't save this data. Documentation requirements likewise vary. 10: For information on electrical resistance trace heating for hazardous (classified), Informational Note No. This value of this LOC differs per substance and depends also on the inert gas for achieving a low oxygen concentration. NEC 2 Divisions (Div 1 2) Division I Comprising of Area Same as Zone 0 1. the inside of tank truck or the interior of a dust filter). 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 . Each chemical gas or vapour used in industry is classified into a gas group. The definition of the hazardous area zones represent the likelihood of hazardous gas, dust or other hazards being present in a working area. 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). The choice of which standard to use for the hazardous area classification is something which is very important. 2: This classification includes, Informational Note No. Area Classification - Hazardous Locations are classified by the likelihood of an ignitable concentration of combustible material being present. January 2023 Group defines the type of the hazardous material in the surrounding atmosphere. less than 0.45 mm or MIC ratio is less than 0.40. of the autoignition temperature of the hazardous atmosphere. It may exist because of repair, maintenance operations, or leakage. FEA Australia and New Zealand use the same IEC-60079 standards (adopted as AS/NZS60079), however the CE mark is not required. No hidden fees. Flour, wood/sawdust, plastic dust). 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. February 2022 Temperature Control Zone 2 hazardous areas are typically storage areas but can also be process areas. Flammable liquids with a high flash point are less hazardous than liquids Zones. SIGN UP FOR EMAILGet more great content in your inbox. 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. There are two sets of Zones: Zones 0 thru 2 are used for gases, vapors, and mists, and Zones 20 thru 22 are . July 2022 In the US, the independent National Fire Protection Association (NFPA) publishes several relevant standards, and they are often adopted by government agencies. 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. Hazardous areas are defined as: " Zones " under worldwide IEC standards (and their local versions, such as ATEX in Europe) " Divisions " under North American NEC standards. If you want to promote your products or services in the Engineering ToolBox - please use Google Adwords. >> For Gas/Vapor this would be Zone 0. To minimize the risk of these fires or explosions, electrical/electronic equipment must be designed, tested and labeled as being acceptable for use in the areas in which it is installed. The process of determining the type and size of hazardous locations is called classification. Zone 0, 1, and 2 locations shall include those specified in 505.5 (B) (1), (B) (2), and (B) (3). And there are three corresponding zones for dust: Zone 20, Zone 21 and Zone 22. Analysers, motors, control boxes, computers, Any arcs or sparks in this equipment has insufficient energy (heat) to ignite a vapour. Some of our calculators and applications let you save application data to your local computer. Zone 22 Zone 21 Zone20 A hazardous atmosphere formed by dust cloud in air is not likely to occur in . Raytec do not currently offer any lighting solutions for Zone 0. 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. 5mm -750C Electrical Resistivity. Atmospheres containing ethylene, propylene oxide, ethylene oxide, butadiene, cyclopropane, ethyl ether, or gases and vapors of equivalent hazard. Determining the Class, Division and Group or Zone and Group is critical to correctly applying the requirements for a given hazardous location. Engineering ToolBox - Resources, Tools and Basic Information for Engineering and Design of Technical Applications! 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. ), Group F Carbon-based (eg. a headlamp, rather than a dedicated fixed luminaire. PROCESS OF CONTAINER 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 Zone 1 fittings are supplied as silver, Zone 2 as dark grey and industrial fittings as white. 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. Beside sufficient fuel, also sufficient oxygen is needed for combustion of the mixture. 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. Classification of areas and selection of equipment and wiring methods shall be under the supervision of a qualified registered professional engineer. (equivalent to NEC Class I, Groups A and B), (equivalent to NEC Class II, Groups F and G), Group IIC is the most severe zone system gas group. Temporary Refuge (TR) Shelter Which Standards to use for Hazardous Area Classification. The substance referred to by classhas a low probability of producing an explosive or ignitable mixture and is present only during abnormal conditions for a short period of time - such as a container failure or system breakdown. In some cases, it must be certified as meeting that standard. 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. THE CURRENT STANDARD . Get more great content like this sent to your inbox. In ambient conditions it is assured that oxygen is always present and thus not a factor that has to be incorporated within the hazardous area assessment. Within the European Union, these are defined by IEC/EN standards (IEC/EN 60079-10-1 or 2) as directed by ATEX. For gases, vapours and mists the zone classifications are recognised as Zone 0, Zone 1 and Zone 2 areas. Carbon monoxide, ether, hydrogen sulfide, . Atmosphere containing a flammable gas, a flammable liquid produced vapor or a combustible liquid-produced vapor whose MESG is greater than 0.75 mm or MIC ratio is greater than 0.40 and less than 0.80 - such as carbon monoxide, ether, hydrogen sulfide, morphline, cyclopropane, ethyl, isoprene, acetaldhyde and ethylene or gases of equivalent hazard. (between 0,1 and 10% of the time). So yes, it is important to choose the right model and always wonder what am I assessing?. Since this fuel can only combust in the presence of oxygen, enough oxygen must be available for the rapid combustion to take place. Lets take a look at what defines each zone. Area which are not devided into Atex zones, are called non-hazardous area's. | For Dust this would be Zone 22. December 2020 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. Informational Note No. The equipment group . 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. Horizontal. For example the EI 15 and API 500/505 describe specific installations and several conditions for the oil and gas industry. Which system is preferred depends on the users preference, how the areas are classified, and the wiring system used. October 2020 Class defines the type of explosive or ignitable substances which are present in the atmosphere. Electronic equipment, including lighting, needs to be purpose designed for use in hazardous areas to prevent a spark occurring and igniting any flammable substances. Industrial electrical equipment for hazardous area has to conform to appropriate parts of standard: IEC-60079 for gas hazards, and IEC-61241 for dust hazards. 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. Note to paragraph (g)(5)(ii)(B) of this section: An example of such a required marking is "Class I, Zone 0, AEx ia IIC T6." Intrinsic safety -- This protection technique is permitted for equipment in the Class I, Zone 0 or Zone 1 locations for which it is approved. NFPA 70 NEC Zone Classification System The Zone Classification System is offered as an alternative to the Class and Division system. Often an area classification plan view is provided to identify equipment ratings and installation techniques to be used for each classified area. 2: Where gas detection, Informational Note No. Pit will be considered as Zone 1. The surface of a high pressure steam pipe may be above the autoignition temperature of some fuel-air mixtures. 1: Normal operation is considered the situation when plant, Informational Note No. Ignitable concentrations of flammable gases or vapors which are not likely to occur under normal operating conditions and do so only for a short period of time. Group II is for explosive gases (Zone 0, 1 and 2) and Group III is for explosive dusts (Zone 20, 21 and 22). But first, we must consider what is likely to cause an explosion in the first place. The colour of the luminaire body indicates the level of protection. Informational Note No. Class I, Zone 0 = Area Classification, AEx = Symbol for equipment built to American specifications, ia = Type of protection designations, IIC = Gas classification group (as required), T6 = Temperature Classification, [46 FR 4056, Jan. 16, 1981; 46 FR 40185, Aug. 7, 1981; 72 FR 7210, Feb. 14, 2007], Occupational Safety & Health Administration. Zone defines thegeneral nature if it is a gas or dust and theprobabilityof hazardous material being present in an ignitable concentration in the surrounding atmosphere. November 2022 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. Comparison of Zone 2 and Division 2 TABLE 1 - AREA CLASSIFICATIONS Division 1: Where ignitable concentrations can exist all of the time or some . April 2022 For Zone 1 applications, Pyroban uses . BATTERY ENERGY STORAGE SYSTEMBESS) You will find this equipment in paint factories, a warehouse or around a bag dump station. >> NEC: Class II, Division 1, Group F. | IEC: Zone 20, Group IIC. Area's are divided into zones. Purged and pressurized -- This protection technique is permitted for equipment in the Class I, Zone 1 or Zone 2 locations for which it is approved. The conduit shall be made wrench tight to prevent sparking when fault current flows through the conduit system and to ensure the explosionproof or flameproof integrity of the conduit system where applicable. Zones 1 or 2. The temperature classification on the electrical equipment label will be one of the following (in degree Celsius): The above table shows that the surface temperature of a piece of electrical equipment with a temperature classification of T3 will not rise above 200C. Refer to Fig.3 which shows the hazardous area zone classification based on hazardous gas release grade. Equipment approved for use in Class I hazardous locations cannot be used in Class II hazardous locations. . September 2022 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. Equipment in this category is intended for use in Zone 0 areas (gases) or Zone 20 (dusts), and must ensure a very high level of protection (i.e. Not only are hazardous areas classified by Class (nature of the hazardous material,) and Division . of Entire Vapour space of storage tank. 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. 14 4. Equipment provided with threaded entries for field wiring connection shall be installed in accordance with paragraph (g)(2)(iv)(A) or (g)(2)(iv)(B) of this section. Dn 1 - a Ce e . So it is quite obvious that explosions should be prevented as much as possible and still work has to be done to achieve this. TLS OFFSHORE CONTAINER This equipment is intended for use in Zone 1 (gases) or Zone 21 (dusts). Category 2 equipment may be used in zone 1 or zone 2 areas. 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. 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. gas, vapours, mists and dusts). July 2021 Figures show that appr. For example, a socket outlet labeled EEx'de' might have a case made to EEx 'e' and switches that are made to EEx 'd'. Offshore Accommodation Module When comparing Divisions and Zones, Division 2 is equivalent to Zone 2, but Division 1 is equivalent to either Zone 0 or 1. October 2018 Methane has a LEL of 4,4 vol%. Arcing electrical equipment in unclassified . Sources 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. The Zones are based on how often the hazard is present rather than upon normal versus abnormal conditions. 1.1 Scope. . The Zone system has three levels of hazard for gas or dust. |MWD/LWD Cabin 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. Adapters shall be used for connection to conduit or NPT-threaded fittings. according to ISO standard 80079 series. Google use cookies for serving our ads and handling visitor statistics. NEW METHODS FOR HAZARDOUS AREA CLASSIFICATION FOR EXPLOSIVE GAS . What is an Explosion Protection Document? A major safety concern in all workplaces is the occurrence of fires and explosions. Cookies are only used in the browser to improve user experience. Q: Can equipment approved for a Class I hazardous location be used in a Class II hazardous location? Hazardous areas are classified into 3 zones based upon the frequency of the occurrence and duration of an explosive gas atmosphere, as follows: Zone 0 Area in which an explosive gas atmosphere is present continuously or for long periods or frequently. Informational Note No. Various regulations use terms such as class, division, zone, and group to differentiate the various hazards. 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! 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. Although every application is different, for the ease of monitoring and specification each hazardous area is classified as a particular level or zone. ethanol, methane or hydrogen. Zone 2. 1.1.1 This recommended practice applies to those locations where flammable gases or vapors, flammable liquids, or combustible liquids are processed or handled; and where their release into the atmosphere could result in their ignition by electrical systems or equipment. Electrical equipment installed in such locations can provide an ignition source, due to electrical arcing, or high temperatures. Since the changes to the code, hazardous locations with gases or vapors (Class I) present can be reclassified as Zone 0, 1 or 2. Different countries have approached the standardization and testing of equipment for hazardous areas in different ways. . Zone 0, 1 2 . Table 1. 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 Magnesium, Titanium), IIB Nonconductive dusts (eg. February 2023 In Europe and the rest of the world - but also more and more in North America - the Zone system is used. The codes and standards used in this process provide guidance for selecting,. This blog post will focus on the different hazardous location classifications and well follow up with another that discusses how equipment can be constructed and certified for use in these environments. Class I hazardous locations are identified by zones as follows: * Zone 0 a location in which explosive gas atmospheres are present continuously or for long periods of time. 1: For examples of area classification drawings, see ANSI/API RP 505-2018, Informational Note No. Hazardous locations can also be described as those locations where electrical equipment September 2018
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