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. 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. This document covers mechanical equipment, in particular fans. The \u201ctype of protection\u201d as specified in EN ISO 80079 37:2016 is constructional safety. 1.4 This document is applicable to fans working in ambient atmospheres and with normal atmospheric conditions at the inlet, having \u2014 absolute pressures ranging from 0,8 bar to 1,1 bar, \u2014 and temperatures ranging from \u221220 \u00b0C to +60 \u00b0C, \u2014 and maximum volume fraction of 21 % oxygen content, \u2014 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 \u221220 \u00b0C 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 \u221220 \u00b0C to +60 \u00b0C the normal ambient temperature range for the equipment is \u221220 \u00b0C to +40 \u00b0C unless otherwise specified and marked. 1.5 This document does not apply to: \u2014 group I fans (fans for mining); \u2014 explosion group IIC (other than hydrogen); \u2014 category 1D fans; \u2014 cooling fans or impellers on rotating electrical machines; \u2014 cooling fans or impellers on internal combustion engines, vehicles or electric motors. NOTE 3 Measures for category 1D fans are given in EN 1127 1:2019. NOTE 4 Measures for explosion group IIC (other than hydrogen) are given in EN 1127 1:2019. NOTE 5 Measures for explosion group I are given in EN ISO\/IEC 80079 38:2016 and EN 1127 2:2014.<\/p>\n
| PDF Pages<\/th>\n | PDF Title<\/th>\n<\/tr>\n | ||||||
|---|---|---|---|---|---|---|---|
| 2<\/td>\n | undefined <\/td>\n<\/tr>\n | ||||||
| 8<\/td>\n | European foreword <\/td>\n<\/tr>\n | ||||||
| 9<\/td>\n | Introduction <\/td>\n<\/tr>\n | ||||||
| 10<\/td>\n | 1 Scope <\/td>\n<\/tr>\n | ||||||
| 11<\/td>\n | 2 Normative references 3 Terms and definitions <\/td>\n<\/tr>\n | ||||||
| 12<\/td>\n | 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 <\/td>\n<\/tr>\n | ||||||
| 13<\/td>\n | 4.1.4 Rare malfunction 4.2 Assignment of categories 4.2.1 General 4.2.2 Influence of external parts on internal hazards and vice-versa 4.2.3 Leakage <\/td>\n<\/tr>\n | ||||||
| 14<\/td>\n | 4.3 Temperatures 4.3.1 General 4.3.2 Maximum surface temperature 4.3.3 Temperature of the conveyed atmosphere (flammable or not) <\/td>\n<\/tr>\n | ||||||
| 15<\/td>\n | 4.4 Mechanical design criteria 4.4.1 General 4.4.2 Clearance between rotating elements and the fan casing <\/td>\n<\/tr>\n | ||||||
| 16<\/td>\n | 4.5 Casing 4.5.1 General 4.5.2 Gas tightness 4.6 Impellers <\/td>\n<\/tr>\n | ||||||
| 17<\/td>\n | 4.7 Materials for rotating and stationary parts of fans 4.7.1 General 4.7.2 Permissible material pairings <\/td>\n<\/tr>\n | ||||||
| 18<\/td>\n | Table 1 \u2014 Permissible material pairings for gas explosion groups IIA and IIB and dust applications <\/td>\n<\/tr>\n | ||||||
| 22<\/td>\n | Table 2 \u2014 Permissible material pairings for gas mixtures containing hydrogen for category 1G and 2G <\/td>\n<\/tr>\n | ||||||
| 23<\/td>\n | 4.8 Linings and tip extensions <\/td>\n<\/tr>\n | ||||||
| 24<\/td>\n | Table 3 \u2014 Minimum thickness of linings 4.9 Vibration <\/td>\n<\/tr>\n | ||||||
| 25<\/td>\n | 4.10 Earthing conducting parts 4.11 Electrostatic charges 4.12 Electrical equipment 4.13 Prevention of deposits inside the fan 4.14 Shaft seals <\/td>\n<\/tr>\n | ||||||
| 26<\/td>\n | 4.15 Bearings 4.16 Power transmission systems 4.17 Clutches and couplings 4.18 Brakes and braking systems 4.19 Impeller-shaft attachment <\/td>\n<\/tr>\n | ||||||
| 27<\/td>\n | Figure 1 \u2014 Fixed bush <\/td>\n<\/tr>\n | ||||||
| 29<\/td>\n | Figure 2 \u2014 Taper bush <\/td>\n<\/tr>\n | ||||||
| 30<\/td>\n | 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 5.3 Vibration <\/td>\n<\/tr>\n | ||||||
| 31<\/td>\n | 5.4 Material pairings 6 Category 1G 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 6.3 Casings 6.3.1 General <\/td>\n<\/tr>\n | ||||||
| 32<\/td>\n | 6.3.2 Gas tightness 7 Information for use 7.1 General 7.2 Accompanying documentation <\/td>\n<\/tr>\n | ||||||
| 34<\/td>\n | 7.3 Markings <\/td>\n<\/tr>\n | ||||||
| 35<\/td>\n | Annex A (normative) Additional requirements for category 1G fans A.1 General A.2 Flame transmission test Figure A.1 \u2014 Test apparatus for the flame transmission test <\/td>\n<\/tr>\n | ||||||
| 36<\/td>\n | A.3 Pressure test <\/td>\n<\/tr>\n | ||||||
| 38<\/td>\n | Annex B (informative) Classification of requirements for the different categories Table B.1 \u2014 Classification of requirements for the different categories <\/td>\n<\/tr>\n | ||||||
| 42<\/td>\n | Annex C (informative) Checklist for verification of the safety requirements and\/or protective measures C.1 General C.2 All categories <\/td>\n<\/tr>\n | ||||||
| 43<\/td>\n | C.3 Category 2 \u2013 Gas and dust C.4 Category 1 \u2013 Gas <\/td>\n<\/tr>\n | ||||||
| 44<\/td>\n | Annex D (informative) Examples of types of fans showing ignition minimizing features Figure D.1 \u2014 Axial fan with fixed pitch blades and ducted inlet for categories 2 and 3 <\/td>\n<\/tr>\n | ||||||
| 45<\/td>\n | Figure D.2 \u2014 Axial fan with variable pitch in-motion ducted inlet-box arrangement <\/td>\n<\/tr>\n | ||||||
| 46<\/td>\n | Figure D.3 \u2014Mixed flow belt driven ducted fan <\/td>\n<\/tr>\n | ||||||
| 47<\/td>\n | Figure D.4 \u2014 Centrifugal fan, coupling driven- ducted arrangement \u2013 General illustration <\/td>\n<\/tr>\n | ||||||
| 48<\/td>\n | Figure D.5 \u2014 Centrifugal fan, coupling driven- ducted arrangement \u2013 Details <\/td>\n<\/tr>\n | ||||||
| 49<\/td>\n | Figure D.6 \u2014 Centrifugal fan, direct driven by foot flanged motor- ducted arrangement <\/td>\n<\/tr>\n | ||||||
| 50<\/td>\n | Figure D.7 \u2014 Centrifugal fan, direct driven by on-flanged motor- ducted arrangement <\/td>\n<\/tr>\n | ||||||
| 51<\/td>\n | Figure D.8 \u2014 Typical fan drive belt guard details <\/td>\n<\/tr>\n | ||||||
| 52<\/td>\n | Annex E (normative) List of significant hazards <\/td>\n<\/tr>\n | ||||||
| 53<\/td>\n | Table E.1 \u2014 Identification of hazards and required countermeasures <\/td>\n<\/tr>\n | ||||||
| 57<\/td>\n | Annex F (informative) Significant changes between this document and EN 14986:2017 Table F.1 \u2014 Significant changes with respect to EN 14986:2017 <\/td>\n<\/tr>\n | ||||||
| 59<\/td>\n | Annex ZA (informative) Relationship between this European Standard and the essential requirements of Directive 2014\/34\/EU aimed to be covered Table ZA.1 \u2014 Correspondence between this European Standard and Directive 2014\/34\/EU <\/td>\n<\/tr>\n | ||||||
| 63<\/td>\n | Bibliography <\/td>\n<\/tr>\n<\/table>\n","protected":false},"excerpt":{"rendered":" Design of fans working in potentially explosive atmospheres<\/b><\/p>\n |