BS EN 14986:2017 – TC:2020 Edition
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Tracked Changes. Design of fans working in potentially explosive atmospheres
Published By | Publication Date | Number of Pages |
BSI | 2020 | 126 |
1.1 This European Standard 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 European Standard are defined in Clause 4. NOTE 2 Technical requirements for category 1 D fans are not given in this document. Where explosive dust atmospheres are regularly conveyed, explosion protection measures as described in EN 1127–1 are required if this specific us is needed. 1.2 This European Standard 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. NOTE 1 Requirements for group I fans are given in EN 1710. NOTE 2 The requirements for electrical parts are covered by references to electrical equipment standards. 1.3 This European Standard 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 may exist inside (the conveyed atmosphere (flammable or not)), outside, or inside and outside of the fan. 1.4 This European Standard 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 European Standard may 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, should clearly demonstrate and indicate the equipment’s suitability for the conditions the fan may encounter. This European Standard should not apply to integral fans as a part of Diesel engines, vehicles or electric motors. NOTE 2 Where undated references are used in the body of the standard the latest edition applies.
PDF Catalog
PDF Pages | PDF Title |
---|---|
78 | 1 Scope |
79 | 2 Normative references 3 Terms and definitions |
80 | 4 Requirements for all fans 4.1 Ignition hazard assessment 4.1.1 General 4.1.2 Normal operating conditions 4.1.3 Expected malfunction 4.1.4 Rare malfunction 4.2 Assignment of categories |
81 | 4.3 Temperatures 4.3.1 General 4.3.2 Maximum surface temperature |
82 | 4.3.3 Temperature of the conveyed atmosphere (flammable or not) 4.4 Mechanical design criteria 4.4.1 General 4.4.2 Clearance between rotating elements and the fan casing |
83 | 4.5 Casing 4.5.1 General 4.5.2 Gas tightness 4.6 Impellers 4.7 Materials for rotating and stationary parts of fans 4.7.1 General |
84 | 4.7.2 Permissible material pairings |
94 | 4.8 Linings and tip extensions 4.9 Vibration |
95 | 4.10 Earthing conducting parts 4.11 Electrostatic charges 4.12 Electrical equipment 4.13 Prevention of deposits inside the fan |
96 | 4.14 Shaft seals 4.15 Bearings 4.16 Power transmission systems 4.17 Clutches and couplings 4.18 Brakes and braking systems 4.19 Impeller-shaft attachment |
100 | 4.20 Corrosion of fan components 4.21 Fire resistance 4.22 Protection against foreign particles 5 Additional requirements for category 2 5.1 General 5.2 Impeller-shaft attachment |
101 | 5.3 Vibration 5.4 Material pairings 6 Category 1 fans for specific use with a gaseous explosive atmosphere as a conveyed atmosphere (flammable or not) 6.1 General requirements 6.2 Flame arresters 6.2.1 General 6.2.2 Stabilized burning |
102 | 6.3 Casings 6.3.1 General 6.3.2 Gas tightness 7 Information for use 7.1 General 7.2 Accompanying documentation |
104 | 7.3 Markings |
105 | Annex A (normative)Additional requirements for category 1 G fans A.1 General A.2 Flame transmission test |
106 | A.3 Pressure test |
107 | Annex B (informative)Classification of requirements for the different categories |
111 | Annex C (informative)Checklist for verification of the safety requirementsand/or protective measures C.1 General C.2 All categories |
112 | C.3 Category 2 – Gas and dust C.4 Category 1 – Gas |
113 | Annex D (informative)Examples of types of fans showing ignition minimizing features |
118 | Annex E (normative)List of significant hazards |
122 | Annex ZA (informative)Relationship between this European Standard and the essential requirements of Directive 2014/34/EU aimed to be covered |