oSIST prEN IEC 60079-10-1:2019

SLOVENSKI STANDARD oSIST prEN IEC 60079-10-1:2019 01-september-2019 Eksplozivne atmosfere - 10-1. del: Razvrstitev prostorov - Eksplozivne plinske atmosfere

Explosive atmospheres - Part 10-1: Classification of areas - Explosive gas atmospheres

2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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Explosive atmospheres - Part 10-1: Classification of areas - Explosive gas atmospheres

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2 CONTENTS ............................................................................................................................ 2

3 FOREWORD ........................................................................................................................... 6

4 INTRODUCTION ..................................................................................................................... 9

5 1 Scope ............................................................................................................................ 10

6 2 Normative references .................................................................................................... 10

7 3 Terms and definitions .................................................................................................... 11

8 4 General ......................................................................................................................... 15

9 4.1 Safety principles ................................................................................................... 15

10 4.2 Hazardous Area classification objectives .............................................................. 16

11 4.3 Interior of equipment containing flammable materials ............................................ 17

12 4.4 Explosion risk assessment .................................................................................... 17

13 4.4.1 General ......................................................................................................... 17

14 4.4.2 Zone of negligible extent ............................................................................... 17

15 4.5 Catastrophic failures ............................................................................................. 18

16 4.6 Competence of personnel ..................................................................................... 18

17 5 Hazardous area classification methodology ................................................................... 18

18 5.1 General ................................................................................................................. 18

19 5.2 Classification by sources of release method .......................................................... 19

20 5.3 Use of industry codes and national standards ....................................................... 20

21 5.3.1 General ......................................................................................................... 20

22 5.3.2 Fuel gas installations ..................................................................................... 20

23 5.4 Simplified methods ............................................................................................... 20

24 5.5 Combination of methods ....................................................................................... 21

25 6 Release of flammable substance ................................................................................... 21

26 6.1 General ................................................................................................................. 21

27 6.2 Sources of release ................................................................................................ 21

28 6.3 Forms of release ................................................................................................... 22

29 6.3.1 General ......................................................................................................... 22

30 6.3.2 Gaseous release ........................................................................................... 23

31 6.3.3 Liquefied under pressure ............................................................................... 23

32 6.3.4 Liquefied by refrigeration ............................................................................... 24

33 6.3.5 Flammable mists ........................................................................................... 24

34 6.3.6 Vapours ......................................................................................................... 24

35 6.3.7 Liquid releases .............................................................................................. 24

36 7 Ventilation (or air movement) and dilution ...................................................................... 25

37 7.1 General ................................................................................................................. 25

38 7.2 Main types of ventilation ....................................................................................... 26

39 7.2.1 Natural ventilation.......................................................................................... 26

40 7.2.2 Artificial ventilation ........................................................................................ 26

41 7.2.3 Degree of dilution .......................................................................................... 28

42 8 Type of zone ................................................................................................................. 29

43 8.1 General ................................................................................................................. 29

44 8.2 Influence of grade of the source of release ........................................................... 29

45 8.3 Influence of dilution ............................................................................................... 29

46 8.4 Influence of availability of ventilation ..................................................................... 29

47 9 Extent of zone ............................................................................................................... 30

48 10 Documentation .............................................................................................................. 30

49 10.1 General ................................................................................................................. 30

50 10.2 Drawings, data sheets and tables ......................................................................... 31

51 Annex A (informative) Suggested presentation of hazardous areas ...................................... 32

52 A.1 Hazardous area zones – Preferred symbols .......................................................... 32

53 A.2 Hazardous area suggested shapes ....................................................................... 35

54 Annex B (informative) Estimation of sources of release........................................................ 37

55 B.1 Symbols ................................................................................................................ 37

56 B.2 Examples of grade of release ................................................................................ 37

57 B.2.1 General ......................................................................................................... 37

58 B.2.2 Sources giving a continuous grade of release ................................................ 38

59 B.2.3 Sources giving a primary grade of release ..................................................... 38

60 B.2.4 Sources giving a secondary grade of release ................................................. 38

61 B.3 Assessment of grades of release .......................................................................... 38

62 B.4 Summation of releases ......................................................................................... 39

63 B.5 Hole size and source radius .................................................................................. 40

64 B.6 Forms of release ................................................................................................... 42

65 B.7 Release rate ......................................................................................................... 43

66 B.7.1 General ......................................................................................................... 43

67 B.7.2 Estimation of Release Rate ........................................................................... 43

68 B.7.3 Release rate of evaporative pools .................................................................. 46

69 B.8 Release from openings in buildings ....................................................................... 48

70 B.8.1 General ......................................................................................................... 48

71 B.8.2 Openings as possible sources of release ....................................................... 48

72 B.8.3 Openings classification .................................................................................. 48

73 Annex C (informative) Ventilation guidance .......................................................................... 50

74 C.1 Symbols ................................................................................................................ 50

75 C.2 General ................................................................................................................. 51

76 C.3 Assessment of ventilation and dilution and its influence on hazardous area .......... 51

77 C.3.1 General ......................................................................................................... 51

78 C.3.2 Effectiveness of ventilation ............................................................................ 52

79 C.3.3 Criteria for dilution ......................................................................................... 52

80 C.3.4 Assessment of ventilation velocity ................................................................. 53

81 C.3.5 Assessment of the degree of dilution ............................................................. 54

82 C.3.6 Dilution in a room .......................................................................................... 56

83 C.3.7 Criteria for availability of ventilation ............................................................... 57

84 C.4 Examples of ventilation arrangements and assessments ....................................... 58

85 C.4.1 Introduction ................................................................................................... 58

86 C.4.2 Jet release in a large building ........................................................................ 59

87 C.4.3 Jet release in a small naturally ventilated building ......................................... 60

88 C.4.4 Jet release in a small artificially ventilated building ........................................ 60

89 C.4.5 Release with low velocity ............................................................................... 61

90 C.4.6 Fugitive emissions ......................................................................................... 61

91 C.4.7 Local ventilation-extraction ............................................................................ 62

92 C.5 Natural Ventilation in buildings .............................................................................. 62

93 C.5.1 General ......................................................................................................... 62

94 C.5.2 Wind induced ventilation ................................................................................ 62

95 C.5.3 Buoyancy induced ventilation......................................................................... 63

96 C.5.4 Combination of the natural ventilation induced by wind and buoyancy ........... 65

97 Annex D (informative) Estimation of hazardous zones.......................................................... 67

98 D.1 General ................................................................................................................. 67

99 D.2 Estimating types of the zones ............................................................................... 67

100 D.3 Estimating the extent of the hazardous zone ......................................................... 68

101 Annex E (informative) Examples of hazardous area classification ........................................ 70

102 E.1 General ................................................................................................................. 70

103 E.2 Examples .............................................................................................................. 70

104 E.3 Example case study for hazardous area classification ........................................... 84

105 Annex F (informative) Schematic approach to classification of hazardous areas .................. 94

106 F.1 Schematic approach to classification of hazardous areas ...................................... 94

107 F.2 Schematic approach to classification of hazardous areas ...................................... 95

108 F.3 Schematic approach to classification of hazardous areas ...................................... 96

109 F.4 Schematic approach to classification of hazardous areas ...................................... 97

110 Annex G (informative) Flammable mists ............................................................................... 98

111 Annex H (informative) Hydrogen ........................................................................................ 101

112 Annex I (informative) Hybrid mixtures ................................................................................ 103

113 I.1 General ............................................................................................................... 103

114 I.2 Use of ventilation ................................................................................................ 103

115 I.3 Concentration limits ............................................................................................ 103

116 I.4 Chemical reactions ............................................................................................. 103

117 I.5 Energy/Temperature limits .................................................................................. 103

118 I.6 Zoning requirements ........................................................................................... 103

119 Annex J (informative) Useful equations in support to hazardous area classification .......... 104

120 J.1 General ............................................................................................................... 104

121 J.2 Dilution with air of a flammable substance release .............................................. 104

122 J.3 Room circulation airflow rates for the releases arising from an enclosure with

123 a fan ................................................................................................................... 104

125 J.4 Estimate of the time required to dilute a flammable substance release ................ 105

126 Annex K (informative) Industry codes and national standards ............................................ 107

127 K.1 General ............................................................................................................... 107

128 Bibliography ........................................................................................................................ 109

130 Figure 1 – Dilution Volume ................................................................................................... 28

131 Figure A.1 – Preferred symbols for hazardous area zones .................................................... 32

132 Figure A.2 – Gas/vapour at low pressure (or at high pressure in case of unpredictable

133 release direction) .................................................................................................................. 35

134 Figure A.3 – Gas/vapour at high pressure ............................................................................. 35

135 Figure A.4 – Liquefied gas .................................................................................................... 36

136 Figure A.5 – Flammable liquid (non boiling evaporative pool) ................................................ 36

137 Figure B.1 – Forms of release ............................................................................................... 42

138 Figure B.2 – Volumetric evaporation rate of liquids ............................................................... 47

139 Figure C.1 – Chart for assessing the degree of dilution ......................................................... 55

140 Figure C.2 – Self diffusion of an unimpeded high velocity jet release .................................... 59

141 Figure C.3 – Supply only ventilation ...................................................................................... 60

142 Figure C.4 – Supply and extraction ventilation ...................................................................... 61

143 Figure C.5 – Local extraction ventilation ............................................................................... 62

144 Figure C.6 – Volumetric flow rate of fresh air per m of equivalent effective opening

146 Figure C.7 – Example of opposing ventilation driving forces ................................................. 66

147 Figure D.1 – Chart for estimating hazardous area distances ................................................. 69

148 Figure E.1 – Degree of dilution (Example No. 1) ................................................................... 71

149 Figure E.2 – Hazardous distance (Example No. 1) ................................................................ 72

150 Figure E.3 – Zone classification (Example No. 1) .................................................................. 72

151 Figure E.4 – Degree of dilution (Example No. 2) ................................................................... 74

152 Figure E.5 – Degree of dilution (Example No. 3) ................................................................... 76

153 Figure E.6 – Hazardous distance (Example No. 3) ................................................................ 77

154 Figure E.7 – Zones classification (Example No. 3) ................................................................ 77

155 Figure E.8 – Degree of dilution (Example No. 4) ................................................................... 79

156 Figure E.9 – Hazardous distance (Example No. 4) ................................................................ 80

157 Figure E.10 – Zones classification (Example No. 4) .............................................................. 80

158 Figure E.11– Degree of dilution (Example No. 5) .................................................................. 83

159 Figure E.13 – Enclosed compressor handling natural gas ..................................................... 86

160 Figure E.14 – Example of hazardous area classification for a compressor facility

161 handling natural gas (elevation) ............................................................................................ 92

162 Figure E.15 – Example of hazardous area classification for a compressor facility

163 handling natural gas (plan) ................................................................................................... 93

164 Figure F.1– Schematic approach to classification ................................................................. 94

165 Figure F.2 – Schematic approach to classification for continuous grade releases .................. 95

166 Figure F.3 – Schematic approach to classification for primary grade releases ....................... 96

167 Figure F.4 – Schematic approach to classification for secondary grade releases .................. 97

169 Table A.1 − Hazardous area classification data sheet – Part I: Flammable substance

170 list and characteristics .......................................................................................................... 33

171 Table A.2 − Hazardous area classification data sheet − Part II: List of sources of

172 release ................................................................................................................................. 34

173 Table B.1 – Suggested hole cross sections for secondary grade of releases ......................... 41

174 Table B.2 – Effect of hazardous zones on openings as possible sources of release ............. 49

175 Table C.1 – Indicative outdoor ventilation velocities (u )....................................................... 54

176 Table D.1 – Zones for grade of release and effectiveness of ventilation ................................ 67

177 Table E.1 – Compressor facility handling natural gas ............................................................ 87

178 Table E.2 – Hazardous area classification data sheet − Part I: Flammable substance

179 list and characteristics .......................................................................................................... 89

180 Table E.3 – Hazardous area classification data sheet − Part II: List of sources of

181 release (1 of 2) ..................................................................................................................... 90

182 Table K.1 – Examples of codes and standards .................................................................... 108

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229 Classification of hazardous areas and installation requirements, of IEC technical

231 This bilingual version (2016-01) corresponds to the English version, published in 2015-09.

232 This third edition of IEC 60079-10-1 cancels and replaces the second edition, published in

233 2015, and constitutes a technical revision. The significant technical changes with respect to