A hazardous area can be defined as any location where there is risk of an explosion. National Electric Code 2020 edition National Fire Protection Association. To prevent explosions from happening in harsh environments whereby flammable gases or combustible dusts are present directives and guidelines are put in place to protect both the public, workforce, and environment. These would be then labeled with each of the individual methods. . Category 2 equipment may be used in zone 1 or zone 2 areas. 3: For further information on the classification of, Informational Note No. 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 . 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. Have a think about it next time youre filling up! In order to understand hazardous area classification it is important to understand which factors contribute to the occurrence of an explosion. Since this fuel can only combust in the presence of oxygen, enough oxygen must be available for the rapid combustion to take place. In Europe and the rest of the world - but also more and more in North America - the Zone system is used. 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. August 2018 WATER TIGHTNESS 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. Zone 2 hazardous areas are typically storage areas but can also be process areas. 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. 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 . Please read AddThis Privacy for more information. Gas a. 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. Class II combustible dusts are grouped into one of three (3) groups: E combustible metal dusts, F combustible carbonaceous dusts or G other combustible dusts. A more quantitative method is described in IEC 60079-10-1 but also more sophisticated numeric mathematical models can be used like Computational Fluid Dynamics. In some cases, the hazardous atmosphere is present all the time, or for long periods. This equipment is intended for use in Zone 1 (gases) or Zone 21 (dusts). Subscribe 6.9K views 2 years ago Oil and Gas Zone Classifications: A) Hazardous Area Classification It's cable reimagined No DVR space limits. An old British standard used letters to designate zones. Refrigerated Enclosures can be pressurized with clean air or inert gas, displacing any hazardous substance. Choose the right method for Hazardous Area Classification! Equipment should be tested to ensure that it does not exceed 80%[according to whom?] 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. Hazardous Areas - North America Classification, international method of area classification, Protection Techniques for Hazardous Areas - North America, Hazardous because combustible or conductive, Atmosphere containing combustible metal dusts, including. (Hazardous Area Classification) . Zone 0 (hazardous area) An area in which an explosive gas-air mixture is continuously present or present for long periods. Oil Immersion "o" -- This protection technique is permitted for equipment in the Class I, Zone 1 locations for which it is approved. September 2018 This is presented by the Lower Explosion Limit (LEL) of a substance. 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. Temporary Refuge (TR) Shelter These ways of protection are specified in detail within several IEC standards (IEC 60079 series) for electrical equipment. These are typically process areas where gases are more likely to be present. Equipment is non-incendive or non-sparking. The International Electrotechnical Commission publishes the 60079 series of standards[2] which defines a system for classification of locations, as well as categorizing and testing of equipment designed for use in hazardous locations, known as "Ex equipment". Locations are thus classified by type and risk of release of gas, vapor, or dust. Zone 2. In the United Kingdom, Sira and Baseefa are the most well known such bodies. 1910.307 - Hazardous (classified) locations. Class I Zone 2 Hazardous Areas. October 2019 LIFTING TEST 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 We don't collect information from our users. February 2021 Accommodation Cabin BATTERY ENERGY STORAGE SYSTEMBESS) |MWD/LWD Cabin In the United States, the most commonly followed system is the NEC (National Electric Code), while the rest of the world generally follows the IEC (International Electrotechnical Commission). 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. The Zone system has wider use in the chemical and petrochemical industries. the National Fire Protection Association (NFPA) 70, National Electric Code(NEC). With the advent of electric power, electricity was introduced into coal mines for signaling, illumination, and motors. The surface of a high pressure steam pipe may be above the autoignition temperature of some fuel-air mixtures. API 500/505 mostly for onshore and offshore oil and gas applications. Ambient Temperature (-20C to +40C if not marked) Establish Zone Based on "IEC 60079-10". 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. Entire Vapour space of storage tank. 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. This means that the electrical equipment is safe for use within these area by applying special protection strategies. Comparisons between the two systems are not easily accomplished. Although every application is different, for the ease of monitoring and specification each hazardous area is classified as a particular level or zone. And safety must be guaranteed in the case of two faults occurring independently of each other. Hazardous locations can also be described as those locations where electrical equipment 5: For further information on ventilation, see NFPA 30-2018, Informational Note No. Equipment marked as suitable for Group IIC is also suitable for IIB and IIA. Sources of Source: Rules and Regulations for the Classification of Mobile Offshore Units, Part 7, Safety Systems, Hazardous Areas and Fire, June 2013, Lloyd's Register, Global Standards. For equipment provided with threaded entries for NPT threaded conduit or fittings, listed conduit, conduit fittings, or cable fittings shall be used. Entire Vapour space of storage tank. So a zone 0 is the most hazardous zone and a zone 2 is a less hazardous zone. Within the European Union, these are defined by IEC/EN standards (IEC/EN 60079-10-1 or 2) as directed by ATEX. The process of determining the type and size of hazardous locations is called classification. . 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. See below for further details: Division system sample marking Equipment meeting one or more of the protection techniques described in paragraph (g)(3) of this section shall be marked with the following in the order shown: Class, except for intrinsically safe apparatus; Zone, except for intrinsically safe apparatus; Occupational Safety and Health Administration, Outreach Training Program (10- and 30-hour Cards), OSHA Training Institute Education Centers, Severe Storm and Flood Recovery Assistance. May 2022 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. 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. Classification of Hazardous Areas 0 100 200 300 400 500 600 T1 >450C T2 >300C 450C T3 >200C 300C T4 >135C 200C . 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. Standards and regulations exist to identify such locations, classify the hazards, and design equipment for safe use in such locations. 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.