ASTM D7236-16a(2021)
(Test Method)Standard Test Method for Flash Point by Small Scale Closed Cup Tester (Ramp Method)
Standard Test Method for Flash Point by Small Scale Closed Cup Tester (Ramp Method)
SIGNIFICANCE AND USE
5.1 The flash point temperature is one measure of the tendency of the test specimen to form a flammable mixture with air under controlled laboratory conditions. It is only one of a number of properties that must be considered in assessing the overall flammability hazard of a material.
5.2 Flash point is used in shipping and safety regulations to define flammable and combustible materials and classify them. Consult the particular regulation involved for precise definitions of these classifications.
5.3 This test method can be used to measure and describe the properties of materials in response to heat and a test flame under controlled laboratory conditions and shall not be used to describe or appraise the fire hazard or fire risk of materials under actual fire conditions. However, results of this test method 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.
SCOPE
1.1 This test method covers the determination of the flash point of aviation turbine fuel, diesel fuel, kerosine and related products in the temperature range of 40 °C to 135 °C by a small scale closed cup apparatus.
1.2 This test method is only applicable to homogeneous materials that are liquid at or near ambient temperature and at temperatures required to perform the test.
1.3 This test method is not applicable to liquids contaminated by traces of highly volatile materials.
1.4 This test method is a dynamic method and depends on a definite rate of temperature increase. It is one of many flash point methods available, and every flash point test method, including this one, is an empirical one.
1.5 If the user's specification requires a defined flash point method, neither this test nor any other method should be substituted for the prescribed method without obtaining comparative data and an agreement from the specifier.
1.6 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.
1.7 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. For specific hazard statements, see Section 7 and the Material Safety Data Sheet for the product being tested.
1.8 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: D7236 − 16a (Reapproved 2021)
Standard Test Method for
Flash Point by Small Scale Closed Cup Tester (Ramp
1,2
Method)
This standard is issued under the fixed designation D7236; 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 flash point test method is a dynamic test method and depends on a definite rate of temperature
increase to control the precision of the test method. The rate of heating may not in all cases give the
precision quoted in the test method because of the low thermal conductivity of certain materials. The
use of an equilibrium method such as Test Methods D3828, Method B improves the prediction of
flammabilityforsuchmaterials,asthevaporsabovethetestspecimenandthetestspecimenarecloser
to thermal equilibrium.
Flash point values are a function of the apparatus design, the condition of the apparatus used, and
the operational procedure carried out. Flash point can therefore only be defined in terms of a standard
test method, and no general valid correlation can be guaranteed between results obtained by different
test methods or with test apparatus different than that specified.
1. Scope 1.6 The values stated in SI units are to be regarded as
standard. No other units of measurement are included in this
1.1 This test method covers the determination of the flash
standard.
point of aviation turbine fuel, diesel fuel, kerosine and related
1.7 This standard does not purport to address all of the
products in the temperature range of 40 °C to 135 °C by a
safety concerns, if any, associated with its use. It is the
small scale closed cup apparatus.
responsibility of the user of this standard to establish appro-
1.2 This test method is only applicable to homogeneous priate safety, health, and environmental practices and deter-
materials that are liquid at or near ambient temperature and at mine the applicability of regulatory limitations prior to use.
temperatures required to perform the test. For specific hazard statements, see Section 7 and the Material
Safety Data Sheet for the product being tested.
1.3 This test method is not applicable to liquids contami-
1.8 This international standard was developed in accor-
nated by traces of highly volatile materials.
dance with internationally recognized principles on standard-
ization established in the Decision on Principles for the
1.4 This test method is a dynamic method and depends on a
Development of International Standards, Guides and Recom-
definite rate of temperature increase. It is one of many flash
mendations issued by the World Trade Organization Technical
point methods available, and every flash point test method,
Barriers to Trade (TBT) Committee.
including this one, is an empirical one.
2. Referenced Documents
1.5 If the user’s specification requires a defined flash point
method, neither this test nor any other method should be
2.1 ASTM Standards:
substituted for the prescribed method without obtaining com-
D3828 Test Methods for Flash Point by Small Scale Closed
parative data and an agreement from the specifier.
Cup Tester
D4057 Practice for Manual Sampling of Petroleum and
Petroleum Products
1 D4177 Practice for Automatic Sampling of Petroleum and
This test method is under the jurisdiction of ASTM Committee D02 on
Petroleum Products, Liquid Fuels, and Lubricants and is the direct responsibility of Petroleum Products
Subcommittee D02.08 on Volatility.
Current edition approved July 1, 2021. Published August 2021. Originally
approved in 2006. Last previous edition approved in 2016 as D7236 – 16a. DOI: For referenced ASTM standards, visit the ASTM website, www.astm.org, or
10.1520/D7236-16AR21. contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
This test method is being jointly developed and harmonized with the Energy Standards volume information, refer to the standard’s Document Summary page on
Institute. the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D7236 − 16a (2021)
D6299 Practice for Applying Statistical Quality Assurance 6. Apparatus
and Control Charting Techniques to Evaluate Analytical
6.1 Flash Point Apparatus—The apparatus consists of an
Measurement System Performance
electrically heated test cup that is controlled automatically to
D6300 Practice for Determination of Precision and Bias
give a temperature increase of 2.0 °C⁄min 6 0.5 °C⁄min, a lid
Data for Use in Test Methods for Petroleum Products,
and shutter assembly, a pilot and test flame, an automatic flash
Liquid Fuels, and Lubricants
detector and a temperature display that displays and holds the
E300 Practice for Sampling Industrial Chemicals
test temperature when a flash is detected. The key parts and
2.2 ISO Standards:
dimensions are described in Annex A1 and illustrated in Fig.
ISO Guide 34 General requirements for the competence of
A1.1.
reference material producers
6.2 Syringe, 2 mL, adjusted to deliver 2.00 mL 6 0.1 mL.
ISO Guide 35 Reference materials—General and statistical
6.3 Barometer, accurate to 0.5 kPa. Barometers pre-
principles for certification
corrected to give sea level readings, such as those used at
3. Terminology weather stations and airports, shall not be used.
NOTE1—Automaticbarometriccorrectioninaccordancewith12.2may
3.1 Definitions:
be installed in the apparatus.
3.1.1 flash point, n—in flash point test methods, the lowest
6.4 Cooling Bath or Freezer, for cooling the samples, if
temperature of the test specimen, adjusted to account for
required, and capable of cooling the sample to at least 10 °C
variations in atmospheric pressure from 101.3 kPa, at which
below the expected flash point. If a freezer is used, it shall be
application of an ignition source causes the vapors of the test
of explosion-protected design.
specimen to ignite under the specified conditions of test.
6.5 Draft Shield, a shield fitted at the back and on two sides
3.2 Definitions of Terms Specific to This Standard:
of the instrument, for use in circumstances where natural
3.2.1 dynamic, adj—the condition where the vapor above
protection from drafts does not exist.
the test specimen, and the test cup, are not in temperature
NOTE 2—A shield 350 mm high, 480 mm wide, and 240 mm deep, is
equilibrium at the time the test flame is applied.
suitable.
3.2.2 ramp method, n—in flash point methods, method that
7. Reagents and Materials
has a test temperature increase at a set rate.
7.1 Cleaning Solvent—Use only noncorrosive solvents ca-
4. Summary of Test Method
pableofcleaningthetestcupandlidassembly.Twocommonly
used solvents are toluene and acetone. (Warning—Toluene,
4.1 A 2 mL 6 0.1 mL test specimen is introduced into the
acetone and many solvents are flammable and a health hazard.
test cup that is then heated automatically at a constant rate of
Dispose of solvents and waste material in accordance with
2 °C⁄min 60.5 °C⁄min.Agastestflameisdirectedthroughan
local regulations.)
opening shutter, in the test cup lid, at specified temperature
intervals until a flash is detected by the automatic flash
7.2 Butane or Natural Gas—For use as the pilot and test
detector. The flash is reported as defined in 3.1.1.
flame. (Warning—Butane and natural gases are flammable
and a health hazard.)
5. Significance and Use
8. Sampling
5.1 The flash point temperature is one measure of the
tendency of the test specimen to form a flammable mixture 8.1 Obtain at least a 25 mL sample from a bulk test site in
with air under controlled laboratory conditions. It is only one accordance with Practices D4057, D4177, E300 or other
of a number of properties that must be considered in assessing comparable sampling practices.
the overall flammability hazard of a material.
8.2 Store samples in clean, tightly sealed containers at
5.2 Flash point is used in shipping and safety regulations to normal room temperature (20 °C to 25 °C) or colder. Ensure
define flammable and combustible materials and classify them. that the container is 85 % to 95 % full.
Consult the particular regulation involved for precise defini-
8.3 Do not store samples for an extended period of time in
tions of these classifications.
gas permeable containers, such as plastic, because volatile
5.3 This test method can be used to measure and describe material may diffuse through the walls of the container.
the properties of materials in response to heat and a test flame Samples in leaky containers are suspect and not a source of
under controlled laboratory conditions and shall not be used to valid results.
describe or appraise the fire hazard or fire risk of materials
8.4 Erroneously high flash points can be obtained when
under actual fire conditions. However, results of this test
precautionsarenottakentoavoidlossofvolatilematerials.Do
method may be used as elements of a fire risk assessment, that
not open containers unnecessarily. Do not make a transfer
takes into account all of the factors that are pertinent to an
unless the sample temperature is at least 10 °C below the
assessment of the fire hazard of a particular end use.
expected flash point.Where possible perform the flash point as
the first test on the sample.
8.5 Samples containing dissolved or free water may be
Available fromAmerican National Standards Institute (ANSI), 25 W. 43rd St.,
4th Floor, New York, NY 10036, http://www.ansi.org. dehydrated with calcium chloride. Warming the sample is
D7236 − 16a (2021)
permitted, but do not heat the sample above a temperature of 11.2 Whenthetestcupisattherequiredtemperature,charge
10 °Cbelowitsexpectedflashpoint.(Warning—Ifthesample a clean and dry syringe (6.2), adjusted to a temperature at least
is expected of containing volatile components, the treatment as 10 °C below the expected flash point, with a 2 mL test
described in 8.5 should be omitted.) specimen. Close the sample container immediately after with-
drawal of the test specimen, to minimize any loss of volatile
8.6 Cool or adjust the temperature of the sample and its
components.
container to at least 10 °C below the expected flash point
beforeopeningtoremovethetestspecimen.Ifanaliquotofthe 11.3 Carefully transfer the syringe to the filler orifice and
original sample is to be stored prior to testing, ensure that the dischargethetestspecimenintothetestcupbyfullydepressing
container is filled to between 85 % and 95 % of its capacity. the syringe plunger. Remove the syringe.
Gently mix the subsample to ensure uniformity while mini-
11.4 Ignite the pilot and test flames.Adjust the test flame to
mizing the possible loss of volatile components and light ends.
conform to the size of the 4 mm gauge ring. Reset the flash
NOTE 3—Results of flash point tests may be affected if the sample
detector (A1.9). Start the test.
volume falls below 85 % of the container’s capacity.
NOTE 8—The ignition of the test flame and control of the gas supply
may be automated on some instruments.
9. Preparation of Apparatus
11.5 The test cup is heated automatically at such a rate that
9.1 Support the apparatus (AnnexA1) on a level and steady
the temperature, as indicated by the temperature sensor, in-
surface in a draft-free position (see Notes 4 and 5).
creases by 1.5 °C⁄min to 2.5 °C⁄min. The test flame is dipped
NOTE 4—A draft shield (6.5) is recommended to be used when natural
into the test cup, as the shutter is slowly and uniformly opened
protection from drafts does not exist.
NOTE 5—When testing materials that may produce toxic vapors, the
and closed over a 2 s to 3 s period, at 1 °C intervals for
apparatus may be located in a fume hood with an individual control of air
temperatures up to and including 100 °C and thereafter every
flow, adjusted such that the toxic vapors can be withdrawn without
2 °C for temperatures over 100 °C.
causing air currents around the test cup during the test.
11.5.1 Observe the first two dips of the flame for continuous
9.2 Clean the test cup, cover, and its accessories with an
burning in the orifice. If a continuous luminous flame burns in
appropriate solvent (7.1) to remove traces of gum or residue
the orifice when the slide is opened and the test flame is
from the previous test.
introduced, then the flash point lies considerably below the test
NOTE6—Astreamofcleandryairmaybeusedtoremovethelasttraces
temperature. In such cases, discontinue the test and repeat the
of solvent used.
test with a fresh test specimen using a lower expected flash
NOTE 7—The filler orifice may be cleaned with a pipe cleaner.
point.
10. Verification of Apparatus
11.5.2 Applicationofthetestflamemaycauseabluehaloor
an enlarged flame prior to the actual flash point. This is not a
10.1 Verify that the temperature measuring device is in
flash and shall be ignored by the flash detector.
accordance with A1.7.
11.6 Record the displayed and held temperature of the
10.2 Verify the performance of the apparatus at least once
temperature sensor when the application of the test flame
peryearbydeterminingtheflashpointofaCertifiedReference
causes a flash to be automatically detected.
Material(CRM)thathasacertifiedflashpointreasonablyclose
to the expected range of the samples to be tested. Examples of
11.7 Recordtheambientbarometricpressureusingabarom-
materials that may be used to create CRMs are listed in
eter (6.3) in the vicinity of the apparatus at the time of the test.
Appendix X1. The flash point shall be determined using the
NOTE 9—It is not considered necessary to correct the barometric
procedures stated in Section 11. Appendix X1 indicates typical pressure reading to 0 °C, although some barometers are designed to make
this correction automatically.
limits in Table X1.1 for a typical CRM and shows how to
calculate limits for an unlisted CRM.
11.8 When the temperature at which the flash is observed is
lessthan10 °Corgreaterthan30 °Cfromthestarttemperature
10.3 Once the performance of the apparatus has been
of the test, the result is not valid. Repeat the test using a fresh
verified using a CRM, the flash point of Secondary Working
test specimen adjusting the temperature of the first application
Standards (SWS) can be determined along with their control
of the test flame until a valid determination is made.
limits. These SWS can then be utilized for more frequent
performance checks. (See Appendix X1.)
12. Calculation
10.4 When the flash point obtained is not within the limits
12.1 Barometric Pressure Conversion—I
...
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