1、Designation: D6450 16Standard Test Method forFlash Point by Continuously Closed Cup (CCCFP) Tester1This standard is issued under the fixed designation D6450; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision
2、. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope*1.1 This flash point test method is a dynamic method anddepends on definite rates of temperature increase. It is one ofthe many flash
3、point test methods available, and every flashpoint test method, including this one, is an empirical method.NOTE 1Flash point values are not a constant physical-chemicalproperty of materials tested. They are a function of the apparatus design,the condition of the apparatus used, and the operational p
4、rocedure carriedout. Flash point can therefore only be defined in terms of a standard testmethod, and no general valid correlation can be guaranteed betweenresults obtained by different test methods or with test apparatus differentfrom that specified.1.2 This test method covers the determination of
5、the flashpoint of fuel oils, lube oils, solvents, and other liquids by acontinuously closed cup tester. The measurement is made on atest specimen of 1 mL.1.3 This test method utilizes a closed but unsealed cup withair injected into the test chamber.1.4 This test method is suitable for testing sample
6、s with aflash point from 10 C to 250 C.NOTE 2Flash point determinations below 10 C and above 250 C canbe performed; however, the precision has not been determined below andabove these temperatures.1.5 If the users specification requires a defined flash pointmethod other than this test method, neithe
7、r this test method norany other method should be substituted for the prescribedmethod without obtaining comparative data and an agreementfrom the specifier.1.6 The values stated in SI units are to be regarded asstandard. No other units of measurement are included in thisstandard. Temperatures are in
8、 degrees Celsius, and pressure isin kilo-pascals.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 re
9、gulatory limitations prior to use. Specific warningstatements appear throughout the standard.2. Referenced Documents2.1 ASTM Standards:2D4057 Practice for Manual Sampling of Petroleum andPetroleum ProductsD4177 Practice for Automatic Sampling of Petroleum andPetroleum ProductsD6299 Practice for Appl
10、ying 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 Products andLubricantsE300 Practice for Sampling Industrial Chemicals2.2 ISO Standard
11、s:3ISO Guide 34 Quality Systems Guidelines for the Produc-tion of Reference MaterialsISO Guide 35 Certifications of Reference Material Generaland Statistical Principles3. Terminology3.1 Definitions:3.1.1 dynamic, adjthe condition in which the vapor abovethe test specimen and the test specimen are no
12、t in temperatureequilibrium at the time at which the ignition source is applied.3.1.2 flash point, nin flash point test methods, the lowesttemperature of the test specimen, adjusted to account forvariations in atmospheric pressure from 101.3 kPa, at whichapplication of an ignition source causes the
13、vapors of the testspecimen to ignite momentarily under specified conditions ofthe test.3.1.2.1 DiscussionFor the purpose of this test method, thetest specimen is deemed to have flashed when the hot flame ofthe ignited vapor causes an instantaneous pressure increase ofat least 20 kPa inside the close
14、d measuring chamber.1This 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 1999. Last p
15、revious edition approved in 2012 as D6450 121. DOI: 10.1520/D6450-16.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM
16、website.3Available from American National Standards Institute (ANSI), 25 W. 43rd St.,4th Floor, New York, NY 10036, http:/www.ansi.org.*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.
17、United States14. Summary of Test Method4.1 The lid of the test chamber is regulated to a temperatureat least 18 C below the expected flash point.A1 mL 6 0.1 mLtest specimen of a sample is introduced into the sample cup,ensuring that both specimen and cup are at a temperature atleast 18 C below the e
18、xpected flash point, cooling if neces-sary. The cup is then raised and pressed onto the lid of specifieddimensions to form the continuously closed but unsealed testchamber with an overall volume of 4.0 mL 6 0.2 mL.4.2 After closing the test chamber, the temperatures of thetest specimen and the regul
19、ated lid are allowed to equilibrate towithin 1 C. Then the lid is heated at a prescribed, constantrate. For the flash tests, an arc of defined energy is dischargedinside the test chamber at regular intervals. After each ignition,1.5 mL 6 0.5 mL of air is introduced into the test chamber toprovide th
20、e necessary oxygen for the next flash test. Thepressure inside the continuously closed but unsealed testchamber remains at ambient barometric pressure, except forthe short time during the air introduction and except at a flashpoint.4.3 After each arc, the instantaneous pressure increaseabove the amb
21、ient barometric pressure inside the test chamberis monitored. When the pressure increase exceeds a definedthreshold, the temperature at that point is recorded as theuncorrected flash point.5. Significance and Use5.1 The flash point temperature is one measure of thetendency of the test specimen to fo
22、rm a flammable mixturewith air under controlled laboratory conditions. It is only oneof a number of properties that must be considered in assessingthe overall flammability hazard of a material.5.2 Flash point is used in shipping and safety regulations todefine flammable and combustible materials and
23、 classify them.This definition may vary from regulation to regulation. Consultthe particular regulation involved for precise definitions ofthese classifications.5.3 This test method can be used to measure and describethe properties of materials in response to heat and an ignitionsource under control
24、led laboratory conditions and shall not beused to describe or appraise the fire hazard or fire risk ofmaterials under actual fire conditions. However, results of thistest method may be used as elements of a fire risk assessment,which takes into account all of the factors that are pertinent toan asse
25、ssment of the fire hazard of a particular end use.5.4 Flash point can also indicate the possible presence ofhighly volatile and flammable materials in a relatively non-volatile or nonflammable material, such as the contaminationof lubricating oils by small amounts of diesel fuel or gasoline.6. Appar
26、atus6.1 Flash Point Apparatus, Continuously Closed CupOperationThe type of apparatus suitable for use in this testmethod employs a lid of solid brass, the temperature of whichis controlled electrically. Two temperature sensors for thespecimen and the lid temperatures, respectively, two electri-cally
27、 insulated pins for a high voltage arc, and a connectingtube for the pressure monitoring and the air introduction areincorporated in the lid. Associated equipment for electricallycontrolling the chamber temperature is used, and a digitalreadout of the specimen temperature is provided. The appara-tus
28、 and its critical elements are shown in Fig. A1.1 and Fig.A1.2.6.1.1 Test ChamberThe test chamber is formed by thesample cup and the temperature controlled lid and shall have anoverall volume of 4 mL 6 0.2 mL. A metal to metal contactbetween the lid and the sample cup shall provide good heatcontact
29、but allow ambient barometric pressure to be maintainedinside the test chamber during the test. Critical dimensions areshown in Fig. A1.2. The pressure inside the measuring cham-ber during the temperature increase is monitored. A seal that istoo tight results in a pressure increase above ambient due
30、to thetemperature and the vapor pressure of the sample. A poor heatcontact results in a bigger temperature difference between thesample and the heated lid.6.1.2 Sample CupThe sample cup shall be made ofnickel-plated aluminum or other material with similar heatconductivity. It shall have an overall v
31、olume of 4 mL and shallbe capable of containing 1 mL 6 0.1 mL of sample. Thecritical dimensions and requirements are shown in Fig. A1.2.6.1.3 Specimen Temperature SensorThe specimen tem-perature sensor (Fig. A1.1: Ts) shall be a thermocouple(NiCr-Ni or similar) in stainless steel of 1 mm diameter wi
32、th aresponse time of t(90)=3s.Itshall be immersed to a depth ofat least 2 mm into the specimen. It shall have a resolution of0.1 C and a minimum accuracy of 6 0.2 C, preferably witha digital readout.6.1.4 Magnetic StirringThe apparatus shall have provi-sions for stirring the sample. A rotating magne
33、t outside thesample cup shall drive a small stirring magnet, which isinserted into the sample cup after sample introduction. Thestirring magnet shall have a diameter of 3 mm 6 0.2 mm anda length of 12 mm 6 1 mm. The rotation speed of the drivingmagnet shall be between 250 rev/min and 270 rev/min.6.1
34、.5 Air IntroductionThe apparatus shall have provisionsfor introduction of 1.5 mL 6 0.5 mL of air immediately aftereach flash test. The air shall be introduced by a short air pulsefrom a small membrane compressor by means of a T-inlet inthe connecting tube to the pressure transducer.6.1.6 Electrical
35、heating and thermoelectric cooling of the lid(Fig. A1.1: PE) shall be used to regulate the temperature of thetest chamber for the duration of the test. The temperatureregulation shall have a minimum accuracy of 6 0.2C.6.1.7 A high voltage electric arc shall be used for theignition of the flammable v
36、apor. The energy of the arc shall be3mJ6 0.5 mJ (3 Ws 6 0.5 Ws) per arc, and the energy shallbe applied within 43 ms 6 3 ms. (WarningBecause samplescontaining low flash material or having a flash point below thepreset initial temperature can oversaturate the vapor inside thechamber and hence prohibi
37、t the detection of a flash point in thechosen range, the design of the apparatus should incorporatestep-wise ignitions in steps of 10C, following the closing ofthe measuring chamber and before the sample reaches theinitial temperature of the test.)D6450 1626.1.8 The pressure transducer for the flash
38、 point detectionshall be connected to the connecting tube in the lid and shallhave a minimum operational range from 80 kPa to 177 kPawith a minimum resolution of 0.1 kPa and a minimumaccuracy of 60.5 kPa. It shall be capable of detecting aninstantaneous pressure increase above barometric pressure of
39、 aminimum of 20 kPa within 100 ms.NOTE 3The monitoring of the instantaneous pressure increase abovebarometric pressure is one of several methods used to determine a flashinside the test chamber. A pressure increase of 20 kPa corresponds to aflame volume of approximately 1.5 mL.NOTE 4An automatic bar
40、ometric correction, which is performed inaccordance with the procedure described in 12.1, can be installed in thetester. The absolute pressure reading of the pressure transducer describedin 6.1.8 may be used for the correction.6.1.9 The introduction of a test portion of 1.0 mL 6 0.1 mLshall be accom
41、plished by the use of a pipette or syringe of therequired accuracy.7. Reagents and Materials7.1 Purity of ReagentsUse only chemicals of purity re-quested in Table X1.1. Unless otherwise indicated, it isintended that all reagents conform to the specifications of theCommittee on Analytical Reagents of
42、 the American ChemicalSociety where such specifications are available.4Other gradesmay be used, provided it is first ascertained that the reagent isof sufficient purity to permit its use without lessening theaccuracy of the determination.7.1.1 Anisole(WarningFlammable and a health hazard.Dispose of
43、solvents and waste material in accordance withlocal regulations.)7.1.2 Dodecane(WarningFlammable and a health haz-ard. Dispose of solvents and waste material in accordance withlocal regulations.)7.2 Cleaning SolventsUse only noncorrosive solvents ca-pable of cleaning the sample cup and the lid. Two
44、commonlyused solvents are toluene and acetone. (WarningFlammableand a health hazard. Dispose of solvents and waste material inaccordance with local regulations.)8. Sampling8.1 Obtain at least a 50 mL sample from a bulk test site inaccordance and instruction given in Practice D4057, D4177,orE300. Sto
45、re the sample in a clean, tightly sealed container at alow temperature.8.2 Do not store samples for an extended period of time ingas permeable containers, such as plastic, because volatilematerial may diffuse through the walls of the container.Discard samples in leaky containers and obtain new sampl
46、es.8.3 Erroneously high flash points can be obtained whenprecautions are not taken to avoid loss of volatile material. Donot open containers unnecessarily. Do not make a transferunless the sample temperature is at least 18 C below theexpected flash point. When possible, perform the flash point asthe
47、 first test.8.4 Samples of very viscous materials may be warmed untilthey are reasonably fluid before they are tested. However, donot heat the unsealed sample above a temperature of 18 Cbelow its expected flash point.8.5 Samples containing dissolved or free water may bedehydrated with calcium chlori
48、de or by filtering through aqualitative filter paper or a loose plug of dry absorbent cotton.Warming the sample is permitted, but do not heat the sampleabove a temperature of 18 C below its expected flash point.(WarningBecause samples containing volatile material willlose volatiles and then yield in
49、correctly high flash points, thetreatment described in 8.4 and 8.5 is not suitable for suchsamples.)9. Quality Control Checks9.1 Verify the performance of the instrument at least onceper year by determining the flash point of a certified referencematerial (CRM) such as those listed in Appendix X1, which isreasonably close to the expected temperature range of thesamples to be tested. The material shall be tested in accordancewith Section 11 of this test method, and the observed flashpoint obtained in 11.11 shall be corrected for barometricpres
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