M/596 - ATEX

This document describes the basic requirements for the design and application of explosion suppression systems. This document also specifies test methods for evaluating the effectiveness and the scaling up of explosion suppression systems against defined explosions. This document covers:
-   general requirements for explosion suppression system parts;
-   evaluating the effectiveness of an explosion suppression system;
-   evaluating the scale up of an explosion suppression system to larger than tested volumes;
-   development and evaluation of design tools for explosion suppression systems;
-   installation, operation and maintenance instructions for an explosion suppression system.
This document is applicable only to explosion suppression systems intended for the protection of closed, or essentially closed, enclosures in which an explosion could result as a consequence of ignition of an explosible mixture, e.g. dust-air, gas(vapour)-air, dust-gas(vapour)-air and mist-air.
This document is not applicable for explosions of materials listed below, or for mixtures containing some of those materials:
-   unstable materials that are liable to dissociate;
-   explosive materials;
-   pyrotechnic materials;
-   pyrophoric materials.

This document specifies terms and definitions (vocabulary) to be used in suitable standards dealing with equipment and protective systems intended for use in potentially explosive atmospheres.
NOTE   Directive 2014/34/EU concerning equipment and protective systems intended for use in potentially explosive atmospheres can be applicable to the type of machine or equipment covered by this document. This document is not intended to provide means of complying with the essential health and safety requirements of Directive 2014/34/EU.

This part of ISO/IEC 80079 covers the technical requirements necessary to avoid or minimize the significant hazards listed in Clause 4, which could occur during normal operation, maintenance or foreseeable malfunction of reciprocating internal combustion engines intended for use in explosive atmospheres including
- Group I EPL Mb for use in underground workings susceptible to firedamp and/or combustible dust,
- Group II EPL Gb and Gc for use in potentially explosive atmospheres of flammable gas and vapour and
- Group III EPL Db and Dc for use in potentially explosive atmospheres of combustible dust.
This part of ISO/IEC 80079 includes those tests of the engine and its ancillary devices that are required to verify compliance.
This part of ISO/IEC 80079 applies to reciprocating internal combustion engines with compression ignition and spark ignition.
This part of ISO/IEC 80079 does not define requirements relating to the driven machinery and equipment.
This part of ISO/IEC 80079 does not apply
- to flammable gas and vapour atmospheres containing carbon disulphide (CS2) and/or ethylene oxide (C2H4O) due to special properties of these gases;
- to explosive mixtures of vapours and gases, which tend to self-decompose (e.g. acetylene) or which are chemically unstable.This International standard does not apply to engines used in areas for the processing manufacture or storage of explosives;
- to gasoline engines and all other liquid injection spark ignited engines.
This part of ISO/IEC 80079 solely deals with explosion protection requirements. Requirements on emissions are not covered by this standard.
General safety requirements are not included in this International Standard.
NOTE 1   General safety requirements i.e. those common to internal combustion engines, are covered for the EU in EN 1679-1:1998+A1:2011.
This part of ISO/IEC 80079 does not specify requirements for safety, other than those directly related to the risk of ignition which may then lead to an explosion.The standard atmospheric conditions (relating to the explosion characteristics of the atmosphere) under which it may be assumed that engine can be operated are:
- temperature -20 °C to +40 °C;
- pressure 80 kPa (0,8 bar) to 110 kPa (1,1 bar); and
- air with normal oxygen content, typically 21 % v/v.
Such atmospheres can also exist inside the engine. In addition, the external atmosphere can be drawn inside the engine by natural breathing produced as a result of fluctuations in the engine's internal operating pressure, and/or temperature.
NOTE 2   It is considered that −20 °C to +40 °C is appropriate for most engines. However for equipment designed for outside this range IEC/TS 60079-43 should be considered.
NOTE 3   The requirements of this standard can also be helpful for the design, construction, testing and marking of engine intended for use in atmospheres outside the validity range stated above. In this case however, the ignition hazard assessment, ignition protection provided, additional testing (if necessary), manufacturer’s technical documentation and instructions to the user, should clearly demonstrate and indicate the engine's suitability for the conditions it may encounter. It should also be recognized that changes in temperature and pressure can have a significant influence on characteristics of the explosive atmosphere, such as ignitability (see Annex I).
NOTE 4   Reciprocating internal combustion engines are not considered as pressure vessels.

This standard specifies the requirements for equipment for firedamp drainage. That equipment can consist of ventilators, pressure generators and safety facilities. This standard also specifies requirements for the installation and monitoring of this equipment.

1.1   This document specifies the constructional requirements for fans constructed to Group II G (of explosion groups IIA, IIB and hydrogen) categories 1, 2 and 3, and Group II D categories 2 and 3, intended for use in explosive atmospheres.
NOTE 1   Operation conditions for the different categories of fans used in this document are defined in Clause 4.
NOTE 2   For category 1 D fans, requirements provided in this document are not sufficient to ensure safety. In addition, explosion protection measures as specified in EN 1127 1:2019 are required to prevent ignition in the case of rare malfunctions.
NOTE 3   Technical requirements for explosion group IIC (other than hydrogen) are not given in this document. Where such atmospheres are present, additional explosion protection measures as specified in EN 1127 1:2019 can be needed.
1.2   This document does not apply to group I fans (fans for mining), cooling fans or impellers on rotating electrical machines, cooling fans or impellers on internal combustion engines, vehicles or electric motors.
NOTE 1   Requirements for group I fans are given in EN ISO/IEC 80079 38:2016.
NOTE 2   The requirements for electrical parts are covered by references to electrical equipment standards.
1.3   This document specifies requirements for design, construction, testing and marking of complete fan units intended for use in potentially explosive atmospheres in air containing gas, vapour, mist and/or dusts. Such atmospheres can exist inside (the conveyed atmosphere (flammable or not)), outside, or inside and outside of the fan.
NOTE   This document covers mechanical equipment, in particular fans. The “protection concept” as specified in EN ISO 80079 37:2016 is constructional safety. Requirements for marking are given in EN ISO 80079 37:2016.
1.4   This document is applicable to fans working in ambient atmospheres and with normal atmospheric conditions at the inlet, having
—   absolute pressures ranging from 0,8 bar to 1,1 bar,
—   and temperatures ranging from −20 °C to +60 °C,
—   and maximum volume fraction of 21 % oxygen content,
—   and an aerodynamic energy increase of less than 25 kJ/kg.
NOTE 1   25 kJ/kg is equivalent to 30 kPa at inlet density of 1,2 kg/m3.
This document can also be helpful for the design, construction, testing and marking of fans intended for use in atmospheres outside the validity range stated above or in cases where other material pairings need to be used. In this case, the ignition risk assessment, ignition protection provided, additional testing (if necessary), manufacturer's marking, technical documentation and instructions to the user, clearly demonstrate and indicate the equipment's suitability for the conditions the fan can encounter.
NOTE 2   Temperatures below −20°C can be considered. Material suitability can require specific evaluation for these temperatures. With lower temperature the explosion pressure increases, which leads to increased test pressures (see A.3) and can require specific testing. Although the standard atmospheric conditions in EN ISO 80079 36:2016 give a temperature range for the atmosphere of −20 °C to +60 °C the normal ambient temperature range for the equipment is −20 °C to +40 °C unless otherwise specified and marked.

2022-09-29 - DOW = DAV + 24months (CEN/TC 305 427/2022 )