1、Designation: D 6811 02 (Reapproved 2007)Designation: 482/02An American National StandardStandard Test Method forMeasurement of Thermal Stability of Aviation Turbine Fuelsunder Turbulent Flow Conditions (HiReTS Method)1, 2This standard is issued under the fixed designation D 6811; the number immediat
2、ely following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope1.1 This tes
3、t method covers a laboratory thermal process,3using a specified apparatus for measuring the tendencies ofaviation turbine fuels to deposit insoluble materials and de-composition products, such as lacquers, within a fuel system.This test method provides a quantitative result for fuel underturbulent f
4、low conditions in 65 or 125 min.1.2 The values stated in SI units are to be regarded as thestandard.1.3 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 heal
5、th practices and determine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:4D 4057 Practice for Manual Sampling of Petroleum andPetroleum ProductsD 4177 Practice for Automatic Sampling of Petroleum andPetroleum ProductsD 4306 Practice for Aviation
6、Fuel Sample Containers forTests Affected by Trace ContaminationE 128 Test Method for Maximum Pore Diameter and Per-meability of Rigid Porous Filters for Laboratory Use3. Terminology3.1 Definitions of Terms Specific to This Standard:3.1.1 capillary tube, na coated resistively heated stainlesssteel tu
7、be through which fuel is pumped and controlled to givea predefined constant fuel exit temperature.3.1.2 deposits, noxidative products, such as lacquers, laiddown predominantly at the fuel exit end (hottest), on the insideof the heated capillary tube.3.1.3 HiReTS, nhigh Reynolds number thermal stabil
8、ity.3.1.4 HiReTS Peak (P) number and Total (T) number,nthe quantitative results of the test.3.1.5 tubeways, nplastic and metal tubes through whichfuel flows during cleaning and the test.4. Summary of Test Method4.1 Fuel is pumped, at pressure, through an electricallyheated capillary tube at a consta
9、nt rate. The heating of thecapillary tube is controlled to maintain a constant fuel tem-perature of 290 6 3C at the exit of the capillary tube. A flowrate of greater than 20 mL/min and the specified capillary boreof less than 0.300 mm ensures that turbulent flow is maintained(see Appendix X1) within
10、 the capillary. The formation oflacquers and fuel degradation products act as a thermalinsulator between the cooler fuel and hotter capillary tube,resulting in an increase in temperature of the capillary tubewhich is measured at a number of positions by a contactlesspyrometer. The HiReTS Total (T) n
11、umber is displayed duringand at the end of the test. The HiReTS Peak (P) number can bedetermined from analysis of the results.5. Significance and Use5.1 The thermal stresses experienced by aviation fuel inmodern jet engines may lead to the formation of undesirableand possibly harmful insoluble mater
12、ials, such as lacquers, on1This test method is under the jurisdiction of ASTM Committee D02 onPetroleum Products and Lubricants and is the direct responsibility of SubcommitteeD02.14 on Stability and Cleanliness of Liquid Fuels.Current edition approved Nov. 1, 2007. Published January 2008. Originall
13、yapproved in 2002. Last previous edition approved in 2002 as D 681102.2This test method is being jointly developed with the Institute of Petroleum,where it is designated IP 482.3This process is covered by a patent. Interested parties are invited to submitinformation regarding the identification of a
14、n alternative(s) to this patented item tothe ASTM Headquarters. Your comments will receive careful consideration at ameeting of the responsible technical committee, which you may attend.4For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceas
15、tm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.heat exchangers and control surfaces, that reduce efficiency
16、and require extra maintenance.5.2 Aircraft fuel systems operate mainly under turbulentflow conditions. Most large-scale realistic test rigs operate inthe turbulent flow regime but fuel volumes are very large andtest times are very long.5.3 This test method tests fuel under turbulent flow (highReynol
17、ds number) conditions, and it gives a quantitative resultunder standard operating conditions of 65 or 125 min. Con-tinuous analysis of results during the test allows performanceof the fuel to be monitored in real time thus enabling the testtime to be reduced manually or automatically, if required.5.
18、4 The results of this test method are not expected tocorrelate with existing test methods for all fuels, since the testmethods and operating conditions are different (see AppendixX2).6. Apparatus (see Annex A1)6.1 General(See Fig.A1.2.) Fuel contained in the samplevessel is drawn through the sample
19、filter by a pump. Thetemperature of the fuel is checked by the input fuel electronicthermometer. The fuel is pumped at a constant rate, at pressureset by the back pressure valve, through an electrically heatedcapillary tube which has a blackened outer surface to give ahigh thermal emissivity. The he
20、ating of the capillary tube iscontrolled to maintain a constant fuel temperature, as measuredby the capillary exit electronic thermometer, at the exit of thecapillary tube. The waste fuel is then cooled to a temperatureof less than 20C above ambient, as measured by the waste fuelelectronic thermomet
21、er, before being discharged to a wastecontainer. During the test, the temperature of the outside of thecapillary tube is scanned, checked and recorded every 5 min at12 points along the exit end of the capillary tube using acontactless pyrometer which is located on a computer-controlled elevating pla
22、tform.6.2 The thermal stability apparatus5and capillary tube5isspecified in detail in Annex A1.6.3 Sparger, of porosity 40 to 80 m, which allows an airflow of approximately 1.5 L/min.NOTE 1The porosity of the sparger can be checked using Test MethodE 128.6.4 Sample Filter, 20-m stainless steel.6.5 A
23、eration Dryer, glass or other suitable transparentmaterial, minimum height 250 mm, minimum diameter 50 mm,filled with dry calcium sulfate and cobalt chloride (see 7.4),which is used in conjunction with an air supply and the sparger(see 6.3) to aerate the test sample.7. Reagents and Materials7.1 Hept
24、ane, CH3(CH2)5CH3, technical grade 95 % purity,for cleaning the apparatus tubeways, and sampling vessels.(WarningExtremely flammable; harmful if inhaled.)7.2 Trisolvent, for cleaning sampling vessels. (WarningEach of the components and the trisolvent is flammable;harmful if inhaled; irritating to sk
25、in, eyes and mucous mem-branes.) It consists of equal volumes of the following:7.2.1 Acetone, CH3COCH3, technical grade, 95 % purity.7.2.2 Toluene, C6H5CH3, technical grade, 95 % purity.7.2.3 Propan-2-ol, (CH3)2CHOH, technical grade, 95 %purity.7.3 Cleaning Solvent, technical grade, 95 % purity, for
26、cleaning sampling vessels. (WarningExtremely flammable;harmful if inhaled.) It consists of one of the following:7.3.1 2-methylpentane.7.3.2 3-methylpentane.7.3.3 2,2,4-trimethylpentane.7.4 Drying Components, to dry the air used for aeration andto indicate the absorption of water by changes from blue
27、 topink color. Use a mix, by volume or weight of the following:7.4.1 Calcium Sulfate Anhydrous Powder, CaSO4(97 %).7.4.2 Cobalt Chloride Anhydrous, CoCl2(3 %) granules.7.5 Air, 1.5 L/min for aeration of the test sample.8. Sampling and Sample Containers8.1 Obtain samples for testing in accordance wit
28、h PracticesD 4057 or D 4177, with the following additional requirements:8.1.1 Containers shall be fully epoxy lined or made ofpolytetrafluoroethylene (PTFE). See Note 2 and PracticeD 4306.8.1.2 Prior to sampling, all containers and their closuresshall be rinsed at least three times with the fuel bei
29、ng sampled.8.1.3 Test samples as soon as possible after sampling.NOTE 2Test methods for measuring thermal stability are known to besensitive to trace contamination during the sampling operation and fromsample containers. New containers are recommended, but when only usedcontainers are available, a t
30、horough rinse with trisolvent (see 7.2)followed by cleaning solvent (see 7.1 and 7.3), and drying with a streamof air is recommended.8.2 Aeration of Test SampleAerate the test sample, withdry air, through the sparger at an air flow rate of 1 to 2 L/minfor 10 min.8.3 Sample SizeStandard operating con
31、ditions are: 3 Lfor13 scans (65min test) and 5 L for 25 scans (125-min test).9. Preparation of Apparatus9.1 Prepare the instrument for operation in accordance withthe manufacturers instructions. (WarningInstalling and re-moving the capillary tube may result in exposure to fuel orsolvent. It is recom
32、mended that impermeable gloves and safetyglasses are worn.)9.2 Remove the sample filter and inlet tubing and clean byrinsing with heptane and then by back flushing with heptane,and then refit.9.3 Set the instrument in accordance with Table 1 and checkthat the correct standard operating conditions ar
33、e in accordancewith Section 10.9.4 Inspect 40 mm of the blackened section at both ends ofthe capillary tube and reject the tube if any scratches, pinholesor cracks are deep enough to expose the capillary tubes brightmetal surface.5The equipment, as listed in the research report being prepared, was u
34、sed todevelop the precision statement. The apparatus and capillary tubes described inAnnexA1 are both supplied by Stanhope-Seta, Chertsey, Surrey KT16 8AP, UK. Todate no other equipment has demonstrated throughASTM interlaboratory testing theability to meet the precision of this test. This is not an
35、 endorsement or certificationby ASTM. A research report is being prepared.D 6811 02 (2007)29.5 Commence the pre-test by installing a new capillarytube and carrying out the following in accordance with themanufacturers instructions.9.6 Immerse the input tube and sample filter in heptane.9.7 Clean the
36、 tubeways with heptane and reset the bypassvalve to TEST.9.8 Visually check the system for leaks. If a leak is found,abort the pre-test and vent the system using the bypass valve.Tighten or replace any leaking fittings, if necessary, and repeat9.6.9.9 Check the alignment and focus of the pyrometer a
37、nd thestraightness of the capillary tube in accordance with themanufacturers handbook.10. Standard Operating Conditions10.1 Fuel Test Temperature, preset at 290C or as specifiedin applicable specifications or as agreed upon between theparties.10.2 Fuel Flow Rate, preset at 35 mL/min or as specified
38、inapplicable specifications or as agreed upon between the parties.10.3 Number of Capillary Scans, preset as 13 (for a 65 mintest) or 25 (for a 125 min test), or as specified in applicablespecifications or as agreed upon between the parties.NOTE 3Each capillary scan takes 5 min to complete.NOTE 4Othe
39、r test temperatures, besides 290C, and flow rates,besides 35 mL/min, can be used but the precision may be affected.11. Calibration and Standardization11.1 Ensure that all of the manufacturers instructions forcalibrating, checking, cleaning, and operating the apparatus arefollowed.11.2 Verify the per
40、formance of the temperature, flow, andpressure sensors at least every 6 months. The testing of fuelswith poor thermal stability may necessitate more frequentequipment verification and cleaning.12. Procedure12.1 Immerse the input tube and clean filter into a cleansample vessel filled with fuel aerate
41、d as in 8.2. The inlet fueltemperature shall be between 15 and 30C as measured by theinput fuel electronic thermometer.12.1.1 Set the bypass valve to TEST, and start the test.12.2 Use the bypass valve to purge the tubeways with thefuel sample. Reset the bypass valve to TEST.NOTE 5The test can only s
42、tart if all independent and computer-monitored safeguards have not detected a fault condition.12.3 Visually check the system for leaks. If a leak is found,abort the test and vent the system by using the bypass valve.Tighten or replace any leaking fittings if necessary and repeat12.3.12.4 Close the c
43、apillary tube enclosure door, ensure that thebypass valve is set to TEST, and commence heating thecapillary tube.NOTE 6The pyrometer commences measuring the temperature of thecapillary tube at the required positions when the fuel exit temperature,from the capillary tube, has stabilized to the prescr
44、ibed value.12.5 At the end of the test remove the sample filter and inlettubing and clean by rinsing with heptane and then by back-flushing with heptane, and then refit. Immerse the input tubeand sample filter in heptane and clean the system in accordancewith the manufacturers instructions. When thi
45、s procedure hasbeen completed, vent the system using the bypass valve.NOTE 7Heptane draining out of the apparatus can be avoided byleaving a capillary tube installed or by capping the upper and lowerunions, and ensuring that the bypass valve is in the TEST position.12.6 The result of the test is aut
46、omatically calculated. (SeeSection 13 for the derivation of the HiReTS Peak and Totalnumbers.)13. Calculation of Result13.1 The HiReTS Total number is the total of the differencebetween the minimum and final temperatures measured at therequired positions, along the surface of the capillary tube,duri
47、ng the test.HiReTS Total number 5dT11dT21dT31dT41dT51dT61dT71dT81dT9 1dTn(1)where:dTn= difference between the minimum and final tempera-tures measured at Position n, C during the test whilethe fuel exit temperature is maintained at a stablelevel.13.2 The HiReTS Peak number is the largest of the diff
48、er-ences between the minimum and final temperatures measuredat any of the required positions, along the surface of thecapillary tube, during the test.13.3 Express the HiReTS Total and Peak results as wholenumbers. Round up any fractions. Use the formats T65, T125,P65 and P125 to denote Total (T) or
49、Peak (P) and the test time.14. Report14.1 Report the source, type, and identification of thematerial tested, plus the date tested.14.2 Report the result of the test (see 13.3) and the numberof capillary scans. Refer to this test method and report anydeviation, by agreement or otherwise, from the procedurespecified.14.3 Record the capillary tube identification.14.4 The report form given in Appendix X3 can be used forstandard and non-standard tests.15. Precision and Bias515.1 The precision of this test method, as determined bystatistical analy
