hazardous area classification zone 0, 1, 2

may exist under normal or abnormal conditions because of the presence of flammable gases or vapors, combustible dusts or ignitable fibers or flyings. Equipment approved for use in Class I hazardous locations cannot be used in Class II hazardous locations. In Europe the label must show the CE mark and the code number of the certifying/notified body). The Zone Classification System is offered as an alternative to the Class and Division system. 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. Group II is for explosive gases (Zone 0, 1 and 2) and Group III is for explosive dusts (Zone 20, 21 and 22). 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. A high level of protection is ensured. 1. 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. Equipment that the employer demonstrates will provide protection from the hazards arising from the flammability of the gas or vapor and the zone of location involved and will be recognized as providing such protection by employees need not be marked. The process of determining the type and size of hazardous locations is called classification. These hazardous (classified) locations are assigned the following designations: For definitions of these locations, see 1910.399. CUTTING SKIPS Zones. >> For Gas Vapor this would be Zone 1. Refrigerated Container Zone 1 - A place in which an explosive atmosphere is likely to occur in normal operation occasionally THE CURRENT STANDARD . 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. Category 1 equipment may be used in zone 0, zone 1 or zone 2 areas. area in which an explosive gas atmosphere is likely to occur occasionally in normal operation. That flammable gas or vapor . In the IEC standards hazardous areas are classified into zones based upon the frequency and duration of an explosive atmosphere. Ex Zone. | For Gas/Vapor this would be Zone 0. July 2022 Sources As a guide for Zone 0, this can be defined as over 1000 hours/year or >10% of the time. For gases, vapours and mists the zone classifications are recognised as Zone 0, Zone 1 and Zone 2 areas. The inductance of the signal bell coils, combined with breaking of contacts by exposed metal surfaces, resulted in sparks, causing an explosion. Enclosures can be pressurized with clean air or inert gas, displacing any hazardous substance. 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. November 2019 RP 505 is referred to as the zone system. lk) are places where fire or explosion hazards may exist. Area which are not devided into Atex zones, are called non-hazardous area's. >> For Gas/Vapor this would be Zone 2. The Zone system of hazardous area classification, defines the probability of the hazardous material, gas, or dust, being present in sufficient quantities that can generate explosive or ignitable mixtures. Division defines the likelihood of the hazardous material being present in an explosive or ignitable concentration.Class I flammable gases and vapors are grouped into one of four groups(Groups A, B, C or D)based on their physical properties and the ease in which they can be ignited. d : HA - ha ea OA - oa Area classification - Divisions vs. zones Continuous hazard Intermittent hazard Hazard under abnormal conditions Zone 0 Zone 1 Zone 2 Division 1 Division 1 Division 2 Hazardous locations - CEC classifications Class I ESS Container The lower explosion limit of a substance is the lowest concentration (in volume percentages for gases and liquids) of a gas or a vapor in air of producing a flash of fire in the presence of an ignition source. 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. National Electrical Code (NEC) and the 1998 Canadian Electrical Code (CEC) now recognize the use of the Zone system for classification of hazardous areas. The plan may contain the list of chemicals with their group and temperature rating. The codes and standards used in this process provide guidance for selecting,. Ignitable concentrations of flammable gases or vapors which are present continuously or for long periods of time. 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). 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. Encapsulation "m" -- This protection technique is permitted for equipment in the Class I, Zone 1 locations for which it is approved. 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. Zone 0 is an area in which an explosive atmosphere is present continuously for long periods of time or will frequently occur. 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. 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. Safe for the hazardous (classified) location. The prevention of explosions in working environments is in most countries regulated in national laws and directives. October 2020 Every substance has a differing combination of properties but it is found that they can be ranked into similar ranges, simplifying the selection of equipment for hazardous areas. Hazardous Area Classifications D103222X012 Product Bulletin 9.2:001 . An oversimplification of this example is shown in Table 1. 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. For equipment provided with threaded entries for NPT threaded conduit or fittings, listed conduit, conduit fittings, or cable fittings shall be used. This page was last edited on 20 January 2023, at 22:32. NFPA 70 NEC Classes, Divisions and Groups. 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. Zone 2 Explosive Mixtures not likely to occur /occur short duration in normal operation (lt10 Hrs/ Yr). 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. This was accompanied by electrically-initiated explosions of flammable gas such as fire damp (methane) and suspended coal dust. Comments. [10][11] Some of these are specifically for hazardous locations: All equipment certified for use in hazardous areas must be labelled to show the type and level of protection applied. Well recognized and clear IEC Standard IEC 60079-10-2:2015 Hazardous Area Classification for explosive dusts Significant influence on spending's for safety . Classification of areas and selection of equipment and wiring methods shall be under the supervision of a qualified registered professional engineer. Type of protection "n" is further subdivided into nA, nC, and nR. Flour, wood/sawdust, plastic dust), IIC Conductive dusts (eg. Atmospheres containing non-conductive dust. In some cases, the hazardous atmosphere is present all the time, or for long periods. You will find these zones at the manifold of a tank truck or the interior of a silo. This has been replaced by a European numerical system, as set out in directive 1999/92/EU implemented in the UK as the Dangerous Substances and Explosives Atmospheres Regulations 2002. A spark or high heat must also be present. 5: For further information on ventilation, see NFPA 30-2018, Informational Note No. ethanol, methane or hydrogen. The flash point determines if an area needs to be classified. This rapid expansion of volume is caused by the combustion of a fuel, like e.g. Zone 0Ignitable concentrations of flammable gases or vapors which are present continuously or for long periods of time. 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." 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 . Temperature classification, except for intrinsically safe apparatus. [3], Different explosive atmospheres have chemical properties that affect the likelihood and severity of an explosion. Within the European Union, these are defined by IEC/EN standards (IEC/EN 60079-10-1 or 2) as directed by ATEX. Where there is potential for an explosive atmosphere, special precautions are needed to prevent fires and explosions. CLASSIFIED LOCATIONS: AREA CLASSIFICATION: AREA CLASSES: AREA GROUPS: LOCATION AS PER DIVISIONS: DIVISION 1 - Class I, Division 1 hazardous locations are defined (as per NEC code Article 500) as follows: DIVISION 2 - Class I Division 2 Locations are as follows: Area Classification by ZONES: DEFINITIONS: HAZARDOUS LOCATIONS: October 2022 . Get more great content like this sent to your inbox. Informational Note No. The relation between that system and de zone classification system is clarified within the following table (only for gases and liquids are displayed, not for dusts and fibers). 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). The flash-point is the temperature at which the material will generate sufficient quantity of vapor to form an ignitable mixture. 3: Text that is followed by a reference in brackets has been extracted from NFPA 497-2017, All other applicable rules contained in this, Where the term "Class I" is used with respect to, Informational Note: The term "Class I" was originally included as a prefix to, All areas in industrial occupancies designated as hazardous (classified). Atmospheres containing propane, acetone, benzene, butane, methane, petrol, hexane, paint solvents or gases and vapors of equivalent hazard. Article 505 National Electrical Code (NEC), Article 506 National Electrical Code (NEC). 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. In Northerm America, instead of the zone classification system, the Class/Division system is used. the National Fire Protection Association (NFPA) 70, National Electric Code(NEC). Typical gas hazards are from hydrocarbon compounds, but hydrogen and ammonia are also common industrial gases that are flammable. Increased safety "e" -- This protection technique is permitted for equipment in the Class I, Zone 1 locations for which it is approved. Group C materials have a MESG less than 0.75mm and a MIC ratio less than 0.80 (but greater than 0.40, which would put it in Group B.) Class I Zone 2 Hazardous Areas. Use this hazardous area guide to NFPA 70 location classes, divisions & groups to understand potentially dangerous situations at a glance. 9: For additional information concerning the installation of, Informational Note No. Zone 1 2. 1.1 Scope. taper per foot. Then, the level of risk of an explosion is based on the frequency and duration of the occurrence of an explosive atmosphere. Zone 0 is an area in which an explosive atmosphere is present continuously for long periods of time or will frequently occur. No long-term contract. HAZARDOUS VS. Intrinsic safety designs equipment to operate using minimal energy, insufficient to cause ignition. The escaping (hot) gases must sufficiently cool down along the escape path that by the time they reach the outside of the enclosure not to be a source of ignition of the outside, potentially ignitable surroundings. The American Petroleum Institute publishes analogous standards in RP500 andRP505. Hazardous area classification is a rigorous method of determining where an explosive environment may be present. A: Yes. The last condition for an explosion is the presence of an effective ignition source in the direct contact with the fuel/air mixture. Workshop Container, Intelligent pressurised container | MUD logging cabin, Battery energy storage system (BESS) container, Laboratory container | workshop container | Equipment containers, Temporary refuge shelter | Toxic gas refuge | Safe haven, Offshore accommodation cabin | office container, Reefer container | Refrigerated container, Intelligent waste water treatment container, IDENTIFYING ZONE 0, ZONE 1, AND ZONE 2 HAZARDOUS AREAS, Temporary refuge (TR) shelter, toxic gas refuge (TGR), Containerised waste water treatment plant. 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). IECEx Karandikar Certification 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. Choose the right method for Hazardous Area Classification! Informational Note No. The following content is only related to flammable substances and not to pyrotechnic substances or other instable substances, among those who can decompose. Where pyrophoric materials are the only materials used or handled, these locations need not be classified. Accommodation Cabin April 2021 Division II Comprising of Area Same as Zone 2. No other aspect of safety receives more attention in the form of codes and standards. The use of EPL and ATEX Category directly is an alternative for "s" marking. Read more in our blogWhich Standards to use for Hazardous Area Classification. Protecting against fire and explosion is of interest for both personnel safety as well as reliability reasons. 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. The last requirement for the explosion is the presence of an ignition source, like a spark or hot surface. Q: Can equipment approved for a Class I hazardous location be used in a Class II hazardous location? Informational Note No. Two possible classifications are described, in Section 18 (Zones), and Appendix J (Divisions). IEC 60079-10-1 covers classification of explosive gas atmospheres, and IEC 60079-10-2 explosive dust. of the autoignition temperature of the hazardous atmosphere. Ways to ensure this level of safety are non-arcing design and limitation of the temperature of the equipment. 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. 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. All threaded conduit shall be threaded with an NPT (National (American) Standard Pipe Taper) standard conduit cutting die that provides -in. 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. 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. (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. In an ordinary household this is of no concern, but if a flammable atmosphere is present, the arc might start an explosion. Gas a. Explosion-proofing designs equipment to contain ignition hazards, prevent entry of hazardous substances, and, contain any fire or explosion that could occur.