ASTM E1226-19
(Test Method)Standard Test Method for Explosibility of Dust Clouds
Standard Test Method for Explosibility of Dust Clouds
SIGNIFICANCE AND USE
5.1 This test method provides a procedure for performing laboratory tests to evaluate deflagration parameters of dusts.
5.2 The data developed by this test method may be used for the purpose of sizing deflagration vents in conjunction with the nomographs and equations published in NFPA 68, ISO 6184/1, or VDI 3673.
5.3 The values obtained by this testing technique are specific to the sample tested and the method used and are not to be considered intrinsic material constants.
5.4 For dusts with low KSt values, discrepancies have been observed between tests in 20-L and 1-m3 chambers. A strong ignitor may overdrive a 20-L chamber, as discussed in Test Method E1515 and Refs (1-4).8 Conversely, more recent testing has shown that some metal dusts can be prone to underdriving in the 20-L chamber, exhibiting significantly lower KSt values than in a 1-m3 chamber (5). Ref (6) provides supporting calculations showing that a test vessel of at least 1-m3 of volume is necessary to obtain the maximum explosibility index for a burning dust cloud having an abnormally high flame temperature. In these two overdriving and underdriving scenarios described above, it is therefore recommended to perform tests in 1-m3 or larger calibrated test vessels in order to measure dusts explosibility parameters accurately.
Note 5: Ref (2) concluded that dusts with KSt values below 45 bar m/s when measured in a 20-L chamber with a 10 000-J ignitor, may not be explosible when tested in a 1-m3 chamber with a 10 000-J ignitor. Ref (2) and unpublished testing has also shown that in some cases the KSt values measured in the 20-L chamber can be lower than those measured in the 1-m3 chamber. Refs (1) and (3) found that for some dusts, it was necessary to use lower ignition energy in the 20-L chamber in order to match MEC or MIC test data in a 1-m3 chamber. If a dust has measurable (nonzero) Pmax and KSt values with a 5000 or 10 000-J ignitor when tested in a 20-L chamber but no measurable Pmax and ...
SCOPE
1.1 Purpose. The purpose of this test method is to provide standard test methods for characterizing the “explosibility” of dust clouds in two ways, first by determining if a dust is “explosible,” meaning a cloud of dust dispersed in air is capable of propagating a deflagration, which could cause a flash fire or explosion; or, if explosible, determining the degree of “explosibility,” meaning the potential explosion hazard of a dust cloud as characterized by the dust explosibility parameters, maximum explosion pressure, Pmax; maximum rate of pressure rise, (dP/dt)max; and explosibility index, KSt.
1.2 Limitations. Results obtained by the application of the methods of this standard pertain only to certain combustion characteristics of dispersed dust clouds. No inference should be drawn from such results relating to the combustion characteristics of dusts in other forms or conditions (for example, ignition temperature or spark ignition energy of dust clouds, ignition properties of dust layers on hot surfaces, ignition of bulk dust in heated environments, etc.)
1.3 Use. It is intended that results obtained by application of this test be used as elements of a dust hazard analysis (DHA) that takes into account other pertinent risk factors; and in the specification of explosion prevention systems (see, for example NFPA 68, NFPA 69, and NFPA 652) when used in conjunction with approved or recognized design methods by those skilled in the art.
Note 1: Historically, the evaluation of the deflagration parameters of maximum pressure and maximum rate of pressure rise has been performed using a 1.2-L Hartmann Apparatus. Test Method E789, which describes this method, has been withdrawn. The use of data obtained from the test method in the design of explosion protection systems is not recommended.
1.4 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.
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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:E1226 −19
Standard Test Method for
1
Explosibility of Dust Clouds
This standard is issued under the fixed designation E1226; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision.Anumber in parentheses indicates the year of last reapproval.A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
INTRODUCTION
Particulate solids of combustible materials present a significant risk of dust explosion if suspended
in air and subjected to an ignition source. The methods of this standard can be used to determine if
a dispersed dust cloud is “explosible” and, if so, to what degree it is explosible, that is, its
“explosibility.” Knowledge that a dust may be explosible if dispersed as a dust cloud is important in
the conduct of a process hazard safety review. Contained herein is an explosibility or go/no-go
screening test procedure for the purpose of determining whether a dust sample is explosible.
If a dust is explosible, the explosibility parameters, maximum explosion pressure, P ; maximum
max
rate of pressure rise, (dP/dt) ; and explosibility index, K , are useful in the design of explosion
max St
prevention and control measures as described in national (NFPA) and international (ISO, CEN and
others) explosion protection standards.
1. Scope NFPA68, NFPA69, and NFPA652) when used in conjunction
with approved or recognized design methods by those skilled
1.1 Purpose. The purpose of this test method is to provide
in the art.
standard test methods for characterizing the “explosibility” of
NOTE 1—Historically, the evaluation of the deflagration parameters of
dust clouds in two ways, first by determining if a dust is
maximumpressureandmaximumrateofpressurerisehasbeenperformed
“explosible,” meaning a cloud of dust dispersed in air is
using a 1.2-L Hartmann Apparatus. Test Method E789, which describes
capable of propagating a deflagration, which could cause a this method, has been withdrawn. The use of data obtained from the test
methodinthedesignofexplosionprotectionsystemsisnotrecommended.
flashfireorexplosion;or,ifexplosible,determiningthedegree
of “explosibility,” meaning the potential explosion hazard of a
1.4 The values stated in SI units are to be regarded as
dust cloud as characterized by the dust explosibility
standard. No other units of measurement are included in this
parameters,maximumexplosionpressure,P ;maximumrate
standard.
max
of pressure rise, (dP/dt) ; and explosibility index, K .
max St
1.5 This standard does not purport to address all of the
1.2 Limitations. Results obtained by the application of the safety concerns, if any, associated with its use. It is the
methods of this standard pertain only to certain combustion
responsibility of the user of this standard to establish appro-
characteristicsofdisperseddustclouds.Noinferenceshouldbe priate safety, health, and environmental practices and deter-
drawn from such results relating to the combustion character-
mine the applicability of regulatory limitations prior to use.
istics of dusts in other forms or conditions (for example, 1.6 This international standard was developed in accor-
ignition temperature or spark ignition energy of dust clouds,
dance with internationally recognized principles on standard-
ignition properties of dust layers on hot surfaces, ignition of ization established in the Decision on Principles for the
bulk dust in heated environments, etc.) Development of International Standards, Guides and Recom-
mendations issued by the World Trade Organization Technical
1.3 Use.Itisintendedthatresultsobtainedbyapplicationof
Barriers to Trade (TBT) Committee.
this test be used as elements of a dust hazard analysis (DHA)
that takes into account other pertinent risk factors; and in the
2. Referenced Documents
specificationofexplosionpreventionsystems(see,forexample
2
2.1 ASTM Standards:
D3173Test Method for Moisture in theAnalysis Sample of
Coal and Coke
1
This test method is under the jurisdiction ofASTM Committee E27 on Hazard
Potential of Chemicals and is the direct responsibility of Subcommittee E27.05 on
2
Explosibility and Ignitability of Dust Clouds. For referenced ASTM standards, visit the ASTM website, www.astm.org, or
Current edition approved Dec. 15, 2019. Published January 2020. Originally contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
approved in 1988. Last previous edition approved in 2012 as E1226–12a. DOI: Standards volume information, refer to the standard’s Document Summary page on
10.1520/E1226-19. the ASTM website.
Copyright © ASTM International, 100 Barr Ha
...
This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Because
it may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current version
of the standard as published by ASTM is to be considered the official document.
Designation: E1226 − 12a E1226 − 19
Standard Test Method for
1
Explosibility of Dust Clouds
This standard is issued under the fixed designation E1226; 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
Particulate solids of combustible materials present a significant risk of dust explosion if suspended
in air and subjected to an ignition source. The methods of this standard can be used to determine if
a dispersed dust cloud is “explosible” and, if so, to what degree it is explosible, that is, its
“explosibility.” Knowledge that a dust may be explosible if dispersed as a dust cloud is important in
the conduct of a process hazard safety review. Contained herein is an explosibility or go/no-go
screening test procedure for the purpose of determining whether a dust sample is explosible.
If a dust is explosible, the explosibility parameters, maximum explosion pressure, P ; maximum
max
rate of pressure rise, (dP/dt)(dP/dt) ; and explosibility index, K , are useful in the design of
max St
explosion prevention and control measures as described in national (NFPA) and international (ISO,
CEN and others) explosion protection standards.
1. Scope
1.1 Purpose. The purpose of this test method is to provide standard test methods for characterizing the “explosibility” of dust
clouds in two ways, first by determining if a dust is “explosible,” meaning a cloud of dust dispersed in air is capable of propagating
a deflagration, which could cause a flash fire or explosion; or, if explosible, determining the degree of “explosibility,” meaning the
potential explosion hazard of a dust cloud as characterized by the dust explosibility parameters, maximum explosion pressure,
P ; maximum rate of pressure rise, (dP/dt)(dP/dt) ; and explosibility index, K .
max max St
1.2 Limitations. Results obtained by the application of the methods of this standard pertain only to certain combustion
characteristics of dispersed dust clouds. No inference should be drawn from such results relating to the combustion characteristics
of dusts in other forms or conditions (for example, ignition temperature or spark ignition energy of dust clouds, ignition properties
of dust layers on hot surfaces, ignition of bulk dust in heated environments, etc.)
1.3 Use. It is intended that results obtained by application of this test be used as elements of an explosion risk assessment a dust
hazard analysis (DHA) that takes into account other pertinent risk factors; and in the specification of explosion prevention systems
(see, for example NFPA 68, NFPA 69, and NFPA 654)652) when used in conjunction with approved or recognized design methods
by those skilled in the art.
NOTE 1—Historically, the evaluation of the deflagration parameters of maximum pressure and maximum rate of pressure rise has been performed using
a 1.2-L Hartmann Apparatus. Test Method E789, which describes this method, has been withdrawn. The use of data obtained from the test method in
the design of explosion protection systems is not recommended.
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.
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.
1
This test method is under the jurisdiction of ASTM Committee E27 on Hazard Potential of Chemicals and is the direct responsibility of Subcommittee E27.05 on
Explosibility and Ignitability of Dust Clouds.
Current edition approved Dec. 1, 2012Dec. 15, 2019. Published January 2013January 2020. Originally approved in 1988. Last previous edition approved in 2012 as
E1226 – 12.E1226 – 12a. DOI: 10.1520/E1226-12A.10.1520/E1226-19.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United Sta
...
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