ASTM E1515-14(2022)
(Test Method)Standard Test Method for Minimum Explosible Concentration of Combustible Dusts
Standard Test Method for Minimum Explosible Concentration of Combustible Dusts
SIGNIFICANCE AND USE
5.1 This test method provides a procedure for performing laboratory tests to evaluate relative deflagration parameters of dusts.
5.2 The MEC as measured by this test method provides a relative measure of the concentration of a dust cloud necessary for an explosion.
5.3 Since the MEC as measured by this test method may vary with the uniformity of the dust dispersion, energy of the ignitor, and propagation criteria, the MEC should be considered a relative rather than absolute measurement.
5.4 If too weak an ignition source is used, the measured MEC would be higher than the “true” value. This is an ignitability limit rather than a flammability limit, and the test could be described as “underdriven.” Ideally, the ignition energy is increased until the measured MEC is independent of ignition energy. However, at some point the ignition energy may become too strong for the size of the test chamber, and the system becomes “overdriven.” When the ignitor flame becomes too large relative to the chamber volume, a test could appear to result in an explosion, while it is actually just dust burning in the ignitor flame with no real propagation beyond the ignitor.
5.5 The recommended ignition source for measuring the MEC of dusts in 20-L chambers is a 2500 or 5000 J pyrotechnic ignitor.4 Measuring the MEC at both ignition energies will provide information on the possible overdriving of the system.5 To evaluate the effect of possible overdriving in a 20-L chamber, comparison tests may also be made in a larger chamber, such as a 1 m3-chamber.
5.6 If a dust ignites with a 5000 J ignitor but not with a 2500 J ignitor in a 20-L chamber, this may be an overdriven system.5 In this case, it is recommended that the dust be tested with a 10 000 J ignitor in a larger chamber, such as a 1 m3-chamber, to determine if it is actually explosible.
5.7 The values obtained by this test method are specific to the sample tested (particularly the particle size distribution) and the met...
SCOPE
1.1 This test method covers the determination of the minimum concentration of a dust-air mixture that will propagate a deflagration in a near-spherical closed vessel of 20 L or greater volume.
Note 1: The minimum explosible concentration (MEC) is also referred to as the lower explosibility limit (LEL) or lean flammability limit (LFL).
1.2 Data obtained from this test method provide a relative measure of the deflagration characteristics of dust clouds.
1.3 This test method should be used to measure and describe the properties of materials in response to heat and flame under controlled laboratory conditions and should not be used to describe or appraise the fire hazard or fire risk of materials, products, or assemblies under actual fire conditions. However, results of this test may be used as elements of a fire risk assessment that takes into account all of the factors that are pertinent to an assessment of the fire hazard of a particular end use.
1.4 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.
1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use. Specific precautionary statements are given in Section 8.
1.6 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
General Information
Relations
Standards Content (Sample)
This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the
Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
Designation:E1515 −14 (Reapproved 2022)
Standard Test Method for
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Minimum Explosible Concentration of Combustible Dusts
This standard is issued under the fixed designation E1515; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
INTRODUCTION
This test method describes procedures for measuring the minimum concentration of a combustible
dust (dispersed in air) that is capable of propagating a deflagration. The tests are made in laboratory
chambers that have volumes of 20 L or larger.
1. Scope ization established in the Decision on Principles for the
Development of International Standards, Guides and Recom-
1.1 This test method covers the determination of the mini-
mendations issued by the World Trade Organization Technical
mum concentration of a dust-air mixture that will propagate a
Barriers to Trade (TBT) Committee.
deflagration in a near-spherical closed vessel of 20 Lor greater
volume.
2. Referenced Documents
NOTE 1—The minimum explosible concentration (MEC) is also re-
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2.1 ASTM Standards:
ferred to as the lower explosibility limit (LEL) or lean flammability limit
D3173 Test Method for Moisture in the Analysis Sample of
(LFL).
Coal and Coke
1.2 Data obtained from this test method provide a relative
D3175 Test Method for Volatile Matter in the Analysis
measure of the deflagration characteristics of dust clouds.
Sample of Coal and Coke
1.3 Thistestmethodshouldbeusedtomeasureanddescribe
E681 Test Method for Concentration Limits of Flammability
the properties of materials in response to heat and flame under
of Chemicals (Vapors and Gases)
controlled laboratory conditions and should not be used to
E1226 Test Method for Explosibility of Dust Clouds
describe or appraise the fire hazard or fire risk of materials,
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2.2 CEN/CENELEC Publications:
products, or assemblies under actual fire conditions. However,
EN 14034–3 Determination of Explosion Characteristics of
results of this test may be used as elements of a fire risk
Dust Clouds – Part 3: Determination of the Lower
assessment that takes into account all of the factors that are
Explosion Limit LEL of Dust Clouds
pertinent to an assessment of the fire hazard of a particular end
use.
3. Terminology
1.4 The values stated in SI units are to be regarded as
3.1 Definitions of Terms Specific to This Standard:
standard. No other units of measurement are included in this
3.1.1 dust concentration, n—the mass of dust divided by the
standard.
internal volume of the test chamber.
1.5 This standard does not purport to address all of the
3.1.2 (dP/dt) ,n—themaximumrateofpressureriseduring
ex
safety concerns, if any, associated with its use. It is the
the course of a single deflagration test.
responsibility of the user of this standard to establish appro-
3.1.3 minimum explosible concentration (MEC), n—the
priate safety, health, and environmental practices and deter-
minimum concentration of a combustible dust cloud that is
mine the applicability of regulatory limitations prior to use.
capable of propagating a deflagration through a well dispersed
Specific precautionary statements are given in Section 8.
mixture of the dust and air under the specified conditions of
1.6 This international standard was developed in accor-
test.
dance with internationally recognized principles on standard-
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This test method is under the jurisdiction ofASTM Committee E27 on Hazard For referenced ASTM standards, visit the ASTM website, www.astm.org, or
Potential of Chemicals and is the direct responsibility of Subcommittee E27.05 on contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
Explosibility and Ignitability of Dust Clouds. Standards volume information, refer to the standard’s Document Summary page on
Current edition approved June 1, 2022. Published June 2022. Originally the ASTM website.
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approved in 1993. Last previous edition approved in 2014 as E1515 – 14. DOI: Available from European Committee for Standardization (CEN), Avenue
10.1520/E1515-14R22. Marnix 17, B-1000, Brussels, Belgium, http://www.cen.eu.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
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E1515−14 (2022)
3.1.4 P ,n—the absolute pressure at the time the ignitor, and propagation criteria, the MEC should be consid-
ignition
ignitor is activated, see Fig. 1. ered a relative rather than absolute measurement.
3.1.5 ∆P ,n—thepressu
...
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