November 2022 Offshore Living Quarter Both external and internal temperatures are taken into consideration. That is why the use of mobile phones on petrol forecourts are banned. For non-ambient conditions, like process reactors or other enclosed systems, the Limiting Oxygen Concentration is often used for the prevention of explosive atmospheres within those enclosed areas. Beside the Lower Explosion Limit, each substance also has an Upper Explosion Limit (UEL). WHEN YOU NEED THEM. Area ClassificationThe max surface temp. In effect it is any method which can be shown to have the required degree of safety in use. 286 natural gas explosions per year in the U.S. causing substantial damage, severe injury or loss of lives. Oxygen is required in high quantities and in combination with the flammable substance to produce an explosive atmosphere. hazardous areas as the following: An area where a potential hazard (e.g., a fire, an explosion, etc.) These generally give rise to areas classied as Zones 0, 1, and 2 respectively. But when we take a closer look at the graph and table, we can conclude that any explosion, can easily lead to severe damage. 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. No. Zone 0, 1, and 2 locations shall include those specified in 505.5 (B) (1), (B) (2), and (B) (3). Different countries have approached the standardization and testing of equipment for hazardous areas in different ways. A Class I, Division 1 or Division 2 location may be reclassified as a Class I, Zone 0, Zone 1, or Zone 2 location only if all of the space that is classified because of a single flammable gas or vapor source is reclassified. Equipment is non-incendive or non-sparking. Zone 0, 1 2 . This is exactly defined as the limiting concentration of oxygen below which combustion is not possible, independent of the concentration of fuel. Group II is for explosive gases (Zone 0, 1 and 2) and Group III is for explosive dusts (Zone 20, 21 and 22). This process is called hazardous area classification. Several protection strategies exist. The colour of the luminaire body indicates the level of protection. . [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. 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. | For Dust this would be Zone 22. AddThis use cookies for handling links to social media. The IEC 60079 standard set has been adapted for use in Australia and New Zealand and is published as the AS/NZS 60079 standard set. (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. Dn 1 - a Ce e . Zone 0Ignitable concentrations of flammable gases or vapors which are present continuously or for long periods of time. [1] NEC article 500 describes the NEC Division classification system, while articles 505 and 506 describe the NEC Zone classification system. 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. This is presented by the Lower Explosion Limit (LEL) of a substance. Cookies are only used in the browser to improve user experience. Equipment marked as suitable for Group IIC is also suitable for IIB and IIA. 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. 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). 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. EN 16985 concerning spray cabins and powder coating cabins, EN 12779 related to extraction systems for hot sawdust and chips, EN 60079-10 series, 2020 version for gas and dust explosion hazard, NPR 7910 series for gas and dust explosion hazard based on EN 60079-10-1, 2015 version, EN 13617 for fuel dispensers at filling stations. Equipment construction is such that it can withstand an internal explosion and provide relief of the external pressure via flamegap(s) such as the labyrinth created by threaded fittings or machined flanges. 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: Requirements for good HAC Drawings and Plans. coal and charcoal), Group G Nonconductive dusts (eg. 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. Well recognized and clear IEC Standard IEC 60079-10-2:2015 Hazardous Area Classification for explosive dusts Significant influence on spending's for safety . Zone 2: An area in which an explosive atmosphere is not likely to occur in normal operation, but if it does . As a guide for Zone 0, this can be defined as over 1,000 hours/year or >10% of the time. The use of EPL and ATEX Category directly is an alternative for "s" marking. Area's are divided into zones. Some of our calculators and applications let you save application data to your local computer. Electronic equipment, including lighting, needs to be purpose designed for use in hazardous areas to prevent a spark occurring and igniting any flammable substances. Hazardous areas are classified into zones based on an assessment of the frequency of the occurrence and duration of an explosive gas atmosphere, as shown in the illustration below. Zone Hazardous Location 2 Table of . 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. *unless risk assessment states a higher or lower category is required. No other aspect of safety receives more attention in the form of codes and standards. 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. The required protection level is linked to the intended use in the zones described below: The equipment category indicates the level of protection offered by the equipment. 2: Through the exercise of ingenuity in the layout of electrical installations for hazardous (classified), Refrigerant machinery rooms that contain ammonia refrigeration systems and are equipped with adequate mechanical ventilation that operates continuously or is initiated by a detection system at a concentration not exceeding 150 ppm shall be permitted to be classified as "unclassified". . 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). The IEC standard EN 60079-33 is made public and is expected to become effective soon, so that the normal Ex certification will also be possible for Ex-s, Zone depending upon manufacturer's certification, explosive atmosphere between 10 and 1000 hrs/yr, explosive atmosphere between 1 and 10 hrs/yr, explosive surface between 10 and 1000 hrs/yr, explosive surface between 1 and 10 hrs/yr, Certified and labeled for use in indoor locations rated NEC Class I, Groups A, B, C, and D, Certified and labeled for use in locations rated NEC Class I, Groups A, B, C, and D; both indoors and outdoors, Certified and labeled for use in locations rated NEC Class II, Groups E, F, or G, Explosion protected, Group 2, Category 1, Gas, Type ia, Group 2C gases, Temperature class 4, Type n, non-sparking, Group 2 gases, Temperature class 3, special conditions apply. Zone 1 2. 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. Feedback From Clients of the autoignition temperature of the hazardous atmosphere. 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. The inductance of the signal bell coils, combined with breaking of contacts by exposed metal surfaces, resulted in sparks, causing an explosion. March 2022 Informational Note No. 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. 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. Container Test ADNOC 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. Home About Us News Hazardous Environment Classifications: NEC vs IEC, Posted March 11, 2019 by springercontrols. Electrical equipment can and does cause fires and/or explosions in certain atmospheres. That flammable gas or vapor . 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. Safety is ensured in the event of frequently occurring disturbances or equipment faults which normally have to be taken into account. Gases, Vapors and Mists. . A list must be drawn up of every explosive material that is on the refinery or chemical complex and included in the site plan of the classified areas. Sources
The NEMA enclosure rating or IP code may also be indicated, but it is usually independent of the Classified Area suitability. Equipment used in hazardous area must comply to certain Ex standards. There are two sets of Zones: Zones 0 thru 2 are used for gases, vapors, and mists, and Zones 20 thru 22 are . Laboratory Container The equipment group . For dusts: Zone 20, Zone 21 and Zone 22. October 2022 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. Terminology for both hazards and protective measures can vary. For more detailed assessments or for situations where no specific industry standards are available , like the chemical or pharmaceutical sector and also specific installation for oil and gas industries, a more quantitative approach can be used. SIGN UP FOR EMAILGet more great content in your inbox. 1: Normal operation is considered the situation when plant, Informational Note No. lk) are places where fire or explosion hazards may exist. Often an area classification plan view is provided to identify equipment ratings and installation techniques to be used for each classified area. Guidance on assessment of hazards is given in NFPA497 (explosive gas) and NFPA499 (dust). Controls can be fitted to detect dangerous concentrations of hazardous gas, or failure of countermeasures. NFPA 70, the National Electrical Code (NEC), defines area classification and installation principles. A major safety concern in all workplaces is the occurrence of fires and explosions. . When equipment must be placed in a hazardous location, it can be designed to reduce the risk of fire or explosion. |MWD/LWD Cabin Quick Tips #124.1. To make this even easier to understand, take a look at the diagram of a typical petrol station below where we have identified the areas that are classified as Zone 0, Zone 1 and Zone 2. For example, in the US by the Occupational Safety and Health Administration. Hazardous locations can also be described as those locations where electrical equipment 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. So the following conditions must be met for an explosion to occur: Represented by the following explosion triangle. You will find this equipment in paint factories, a warehouse or around a bag dump station. Determining the Class, Division and Group or Zone and Group is critical to correctly applying the requirements for a given hazardous location. This article covers the requirements for the, Informational Note No. For methane this is shown in the following figure. 11: For information on electric skin effect trace heating for hazardous (classified), Informational Note No. Group defines the type of the hazardous material in the surrounding atmosphere. Within a working area or installation an ignition can be created by many factors. In Europe the label must show the CE mark and the code number of the certifying/notified body). As to the classification, they are the same. 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. Please read Google Privacy & Terms for more information about how you can control adserving and the information collected. All threaded conduit shall be threaded with an NPT (National (American) Standard Pipe Taper) standard conduit cutting die that provides -in. 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. January 2022 A material may have a relatively low autoignition temperature yet if its flash-point is above the ambient temperature, then the area may not need to be classified. The flash-point is the temperature at which the material will generate sufficient quantity of vapor to form an ignitable mixture. 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. August 2020 Which system is preferred depends on the users preference, how the areas are classified, and the wiring system used. May 2022 FREEZER NFPA 70 NEC Zone Classification System The Zone Classification System is offered as an alternative to the Class and Division system. Sources of such hazards include gases, vapors, dust, fibers, and flyings, which are combustible or flammable. Conversely if the same material is heated and handled above its flash-point, the area must be classified for proper electrical system design, as it will then form an ignitable mixture.[5]. IEC 60079-10.1 Classification of areas - Explosive gas atmospheres. 5: For further information on ventilation, see NFPA 30-2018, Informational Note No. Ignitable concentrations of flammable gases or vapors which are present continuously or for long periods of time. gas, vapours, mists and dusts). Zone 2 Explosive Mixtures not likely to occur /occur short duration in normal operation (lt10 Hrs/ Yr). Click on the zone to learn more about the classification according to IEC 60079-10 standards. The NEC Zone system was created to harmonize with IEC classification system, and therefore reduce the complexity of management. Raytec do not currently offer any lighting solutions for Zone 0. 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. to EN 1127-1): After the hazard area classification is completed, then the ignition assessment starts. 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. ESS Container In other cases, the atmosphere is normally non-hazardous, but a dangerous concentration can be reasonably foreseensuch as operator error or equipment failure. There are several ways of how to perform hazardous area classification, all described in several standards or codes of practise. 1: As a guide to classification of Zone 22 locations, refer to ANSI/ISA 60079-10-2 (12.10.05)-2013, Explosive Atmospheres Part 10-2: Classification of areas Combustible dust atmospheres. Refrigerated Container June 2022 When the concentration of gas or vapor is above the UEL the gas mixture is too rich to burn. The Class/Division/Group system is based on Article 500 of the National Electrical Code (NEC) where. TLS OFFSHORE CONTAINER Although every application is different, for the ease of monitoring and specification each hazardous area is classified as a particular level or zone. So a zone 0 is the most hazardous zone and a zone 2 is a less hazardous zone. 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. The key difference between Divisions and Zones relate to terminations. Zone 0/20: An area in which an explosive atmosphere is present continuously or for long periods or frequently. Zone 1 - A place in which an explosive atmosphere is likely to occur in normal operation occasionally Zone 2 hazardous areas are typically storage areas but can also be process areas. Comments. NEW METHODS FOR HAZARDOUS AREA CLASSIFICATION FOR EXPLOSIVE GAS . . Q: Are Divisions and Zones equivalent to one another? Comparisons between the two systems are not easily accomplished. 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! A: Yes. This temperature is used for classification for industry and technology applications.[6]. Note to paragraph (c)(3) of this section: The National Electrical Code, NFPA 70, contains guidelines for determining the type and design of equipment and installations that will meet this requirement. In some cases, the hazardous atmosphere is present all the time, or for long periods. Substance properties are specific for the amount of fuel needed to get an explosion when all other conditions are met. 0,1 or 2: II B: I: 1 or 2: C: Acetone Benzene Butane Hexane . >> For Gas/Vapor this would be Zone 0. 29 CFR 1910.399 Definitions Applicable to Subpart S
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. 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.) Powder Filling "q" -- This protection technique is permitted for equipment in the Class I, Zone 1 locations for which it is approved. Groups E, F, and G are for dusts and flyings (Class II or III). March 2021 .14 . Locations shall be classified depending on the properties of the flammable vapors, liquids, or gases that may be present and the likelihood that a flammable or combustible concentration or quantity is present. It uses the familiar Class/Division system and adapts the IEC/CENELEC Zones into it while maintaining NEC wiring methods and . Lets take a look at what defines each zone. Have a think about it next time youre filling up! 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. November 2020 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.