1、Designation: D7236 16Standard Test Method forFlash Point by Small Scale Closed Cup Tester (RampMethod)1,2This standard is issued under the fixed designation D7236; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last re
2、vision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.INTRODUCTIONThis flash point test method is a dynamic test method and depends on a definite rate of temperatureincrease to control the pr
3、ecision of the test method. The rate of heating may not in all cases give theprecision quoted in the test method because of the low thermal conductivity of certain materials. Theuse of an equilibrium method such as Test Methods D3828, Method B improves the prediction offlammability for such material
4、s, as the vapors above the test specimen and the test specimen are closerto thermal equilibrium.Flash point values are a function of the apparatus design, the condition of the apparatus used, andthe operational procedure carried out. Flash point can therefore only be defined in terms of a standardte
5、st method, and no general valid correlation can be guaranteed between results obtained by differenttest methods or with test apparatus different than that specified.1. Scope*1.1 This test method covers the determination of the flashpoint of aviation turbine fuel, diesel fuel, kerosine and relatedpro
6、ducts in the temperature range of 40 C to 135 C by asmall scale closed cup apparatus.1.2 This test method is only applicable to homogeneousmaterials that are liquid at or near ambient temperature and attemperatures required to perform the test.1.3 This test method is not applicable to liquids contam
7、i-nated by traces of highly volatile materials.1.4 This test method is a dynamic method and depends on adefinite rate of temperature increase. It is one of many flashpoint methods available, and every flash point test method,including this one, is an empirical one.1.5 If the users specification requ
8、ires a defined flash pointmethod, neither this test nor any other method should besubstituted for the prescribed method without obtaining com-parative data and an agreement from the specifier.1.6 The values stated in SI units are to be regarded asstandard. No other units of measurement are included
9、in thisstandard.1.7 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use
10、. For specific hazardstatements, see Section 7 and the Material Safety Data Sheetfor the product being tested.2. Referenced Documents2.1 ASTM Standards:3D3828 Test Methods for Flash Point by Small Scale ClosedCup TesterD4057 Practice for Manual Sampling of Petroleum andPetroleum ProductsD4177 Practi
11、ce for Automatic Sampling of Petroleum andPetroleum ProductsD6299 Practice for Applying Statistical Quality Assuranceand Control Charting Techniques to Evaluate AnalyticalMeasurement System PerformanceD6300 Practice for Determination of Precision and BiasData for Use in Test Methods for Petroleum Pr
12、oducts andLubricants1This test method is under the jurisdiction of ASTM Committee D02 onPetroleum Products, Liquid Fuels, and Lubricants and is the direct responsibility ofSubcommittee D02.08 on Volatility.Current edition approved June 1, 2016. Published July 2016. Originally approvedin 2006. Last p
13、revious edition approved in 2013 as D7236 07 (2013). DOI:10.1520/D7236-16.2This test method is being jointly developed and harmonized with the EnergyInstitute.3For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of
14、ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.*A Summary of Changes section appears at the end of this standardCopyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States1E300 Practice for Sampl
15、ing Industrial Chemicals2.2 ISO Standards:4ISO Guide 34 Quality Systems Guidelines for the Produc-tion of Reference MaterialsISO Guide 35 Certification of Reference MaterialGeneraland Statistical Principles3. Terminology3.1 Definitions:3.1.1 flash point, nin flash point test methods, the lowesttempe
16、rature of the test specimen, adjusted to account forvariations in atmospheric pressure from 101.3 kPa, at whichapplication of an ignition source causes the vapors of the testspecimen to ignite under the specified conditions of test.3.2 Definitions of Terms Specific to This Standard:3.2.1 dynamic, ad
17、jthe condition where the vapor abovethe test specimen, and the test cup, are not in temperatureequilibrium at the time the test flame is applied.3.2.2 ramp method, nin flash point methods, method thathas a test temperature increase at a set rate.4. Summary of Test Method4.1 A 2 mL 6 0.1 mL test spec
18、imen is introduced into thetest cup that is then heated automatically at a constant rate of2 C min 6 0.5 C min.Agas test flame is directed through anopening shutter, in the test cup lid, at specified temperatureintervals until a flash is detected by the automatic flashdetector. The flash is reported
19、 as defined in 3.1.1.5. Significance and Use5.1 The flash point temperature is one measure of thetendency of the test specimen to form a flammable mixturewith air under controlled laboratory conditions. It is only oneof a number of properties that must be considered in assessingthe overall flammabil
20、ity hazard of a material.5.2 Flash point is used in shipping and safety regulations todefine flammable and combustible materials and classify them.Consult the particular regulation involved for precise defini-tions of these classifications.5.3 This test method can be used to measure and describethe
21、properties of materials in response to heat and a test flameunder controlled laboratory conditions and shall not be used todescribe or appraise the fire hazard or fire risk of materialsunder actual fire conditions. However, results of this testmethod may be used as elements of a fire risk assessment
22、, thattakes into account all of the factors that are pertinent to anassessment of the fire hazard of a particular end use.6. Apparatus6.1 Flash Point ApparatusThe apparatus consists of anelectrically heated test cup that is controlled automatically togive a temperature increase of 2.0 C min 6 0.5 C
23、min, a lidand shutter assembly, a pilot and test flame, an automatic flashdetector and a temperature display that displays and holds thetest temperature when a flash is detected. The key parts anddimensions are described in Annex A1 and illustrated in Fig.A1.1.6.2 Syringe, 2 mL, adjusted to deliver
24、2.00 mL 6 0.1 mL.6.3 Barometer, accurate to 0.5 kPa. Barometers pre-corrected to give sea level readings, such as those used atweather stations and airports, shall not be used.NOTE 1Automatic barometric correction in accordance with 12.2 maybe installed in the apparatus.6.4 Cooling Bath or Freezer,
25、for cooling the samples, ifrequired, and capable of cooling the sample to at least 10 Cbelow the expected flash point. If a freezer is used, it shall beof explosion-protected design.6.5 Draft Shield, a shield fitted at the back and on two sidesof the instrument, for use in circumstances where natura
26、lprotection from drafts does not exist.NOTE 2A shield 350 mm high, 480 mm wide, and 240 mm deep, issuitable.7. Reagents and Materials7.1 Cleaning SolventUse only noncorrosive solvents ca-pable of cleaning the test cup and lid assembly. Two commonlyused solvents are toluene and acetone. (WarningTolue
27、ne,acetone and many solvents are flammable and a health hazard.Dispose of solvents and waste material in accordance withlocal regulations.)7.2 Butane or Natural GasFor use as the pilot and testflame. (WarningButane and natural gases are flammableand a health hazard.)8. Sampling8.1 Obtain at least a
28、25 mL sample from a bulk test site inaccordance with Practices D4057, D4177, E300 or othercomparable sampling practices.8.2 Store samples in clean, tightly sealed containers atnormal room temperature (20 C to 25 C) or colder. Ensurethat the container is 85 % to 95 % full.8.3 Do not store samples for
29、 an extended period of time ingas permeable containers, such as plastic, because volatilematerial may diffuse through the walls of the container.Samples in leaky containers are suspect and not a source ofvalid results.8.4 Erroneously high flash points can be obtained whenprecautions are not taken to
30、 avoid loss of volatile materials. Donot open containers unnecessarily. Do not make a transferunless the sample temperature is at least 10 C below theexpected flash point. Where possible perform the flash point asthe first test on the sample.8.5 Samples containing dissolved or free water may bedehyd
31、rated with calcium chloride. Warming the sample ispermitted, but do not heat the sample above a temperature of10 C below its expected flash point. (WarningIf the sampleis expected of containing volatile components, the treatment asdescribed in 8.5 should be omitted.)8.6 Cool or adjust the temperatur
32、e of the sample and itscontainer to at least 10 C below the expected flash point4Available from American National Standards Institute (ANSI), 25 W. 43rd St.,4th Floor, New York, NY 10036, http:/www.ansi.org.D7236 162before opening to remove the test specimen. If an aliquot of theoriginal sample is t
33、o be stored prior to testing, ensure that thecontainer is filled to between 85 % and 95 % of its capacity.Gently mix the subsample to ensure uniformity while mini-mizing the possible loss of volatile components and light ends.NOTE 3Results of flash point tests may be affected if the samplevolume fal
34、ls below 85 % of the containers capacity.9. Preparation of Apparatus9.1 Support the apparatus (Annex A1) on a level and steadysurface in a draft-free position (see Notes 4 and 5).NOTE 4A draft shield (6.5) is recommended to be used when naturalprotection from drafts does not exist.NOTE 5When testing
35、 materials that may produce toxic vapors, theapparatus may be located in a fume hood with an individual control of airflow, adjusted such that the toxic vapors can be withdrawn withoutcausing air currents around the test cup during the test.9.2 Clean the test cup, cover, and its accessories with ana
36、ppropriate solvent (7.1) to remove traces of gum or residuefrom the previous test.NOTE 6Astream of clean dry air may be used to remove the last tracesof solvent used.NOTE 7The filler orifice may be cleaned with a pipe cleaner.10. Verification of Apparatus10.1 Verify that the temperature measuring de
37、vice is inaccordance with A1.7.10.2 Verify the performance of the apparatus at least onceper year by determining the flash point of a Certified ReferenceMaterial (CRM) that has a certified flash point reasonably closeto the expected range of the samples to be tested. Examples ofmaterials that may be
38、 used to create CRMs are listed inAppendix X1. The flash point shall be determined using theprocedures stated in Section 11. Appendix X1 indicates typicallimits in Table X1.1 for a typical CRM and shows how tocalculate limits for an unlisted CRM.10.3 Once the performance of the apparatus has beenver
39、ified using a CRM, the flash point of Secondary WorkingStandards (SWS) can be determined along with their controllimits. These SWS can then be utilized for more frequentperformance checks. (See Appendix X1.)10.4 When the flash point obtained is not within the limitsstated in 10.2 or 10.3 check the c
40、ondition and operation of theapparatus to ensure conformance to the details listed in AnnexA1, especially with regard to the action of the shutter, theposition and size of the test flame, the heating rate and thetemperature sensor readings. After any adjustment, repeat thetest in 10.2 or 10.3 using
41、a fresh test specimen, with specialattention to the procedural details prescribed in the test method.11. Procedure11.1 Set the test cup temperature to 15 C 6 5 C below theexpected flash point temperature.11.2 When the test cup is at the required temperature, chargea clean and dry syringe (6.2), adju
42、sted to a temperature at least10 C below the expected flash point, with a 2 mL testspecimen. Close the sample container immediately after with-drawal of the test specimen, to minimize any loss of volatilecomponents.11.3 Carefully transfer the syringe to the filler orifice anddischarge the test speci
43、men into the test cup by fully depressingthe syringe plunger. Remove the syringe.11.4 Ignite the pilot and test flames. Adjust the test flame toconform to the size of the 4 mm gauge ring. Reset the flashdetector (A1.9). Start the test.NOTE 8The ignition of the test flame and control of the gas suppl
44、ymay be automated on some instruments.11.5 The test cup is heated automatically at such a rate thatthe temperature, as indicated by the temperature sensor, in-creases by 1.5 C min to 2.5 C min. The test flame is dippedinto the test cup, as the shutter is slowly and uniformly openedand closed over a
45、2 s to 3 s period, at 1 C intervals fortemperatures up to and including 100 C and thereafter every2 C for temperatures over 100 C.11.5.1 Observe the first two dips of the flame for continuousburning in the orifice. If a continuous luminous flame burns inthe orifice when the slide is opened and the t
46、est flame isintroduced, then the flash point lies considerably below the testtemperature. In such cases, discontinue the test and repeat thetest with a fresh test specimen using a lower expected flashpoint.11.5.2 Application of the test flame may cause a blue halo oran enlarged flame prior to the ac
47、tual flash point. This is not aflash and shall be ignored by the flash detector.11.6 Record the displayed and held temperature of thetemperature sensor when the application of the test flamecauses a flash to be automatically detected.11.7 Record the ambient barometric pressure using a barom-eter (6.
48、3) in the vicinity of the apparatus at the time of the test.NOTE 9It is not considered necessary to correct the barometricpressure reading to 0 C, although some barometers are designed to makethis correction automatically.11.8 When the temperature at which the flash is observed isless than 10 C or g
49、reater than 30 C from the start temperatureof the test, the result is not valid. Repeat the test using a freshtest specimen adjusting the temperature of the first applicationof the test flame until a valid determination is made.12. Calculation12.1 Barometric Pressure ConversionIf the barometricpressure reading is measured in a unit other than kilopascals,convert to kilopascals using one of the following equations:Reading in hPa 30.1 5 kPa (1)Reading in mbar 30.1 5 kPa (2)Reading in mmHg 30.1333 5 kPa (3)12.2 Correction of Detected
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