1、Designation: D 6811 02Designation: 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 immediately following the d
2、esignation 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 (e) indicates an editorial change since the last revision or reapproval.1. Scope1.1 This test method covers a
3、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 flow conditions in
4、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 health practices and d
5、etermine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:D 4057 Practice for Manual Sampling of Petroleum andPetroleum Products4D 4177 Practice for Automatic Sampling of Petroleum andPetroleum Products4D 4306 Practice for Aviation Fuel Sample Conta
6、iners forTests Affected by Trace Contamination4E 128 Test Method for Maximum Pore Diameter and Per-meability of Rigid Porous Filters for Laboratory Use53. Terminology3.1 Definitions of Terms Specific to This Standard:3.1.1 capillary tube, na coated resistively heated stainlesssteel tube through whic
7、h 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 stability.3.1.4 HiReT
8、S 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 constant rate. The he
9、ating 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 the capillary.
10、 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) number is displa
11、yed 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 materials, such as l
12、acquers, onheat exchangers and control surfaces, that reduce efficiencyand require extra maintenance.1This test method is under the jurisdiction of ASTM Committee D02 onPetroleum Products and Lubricantsand is the direct responsibility of SubcommitteeD02.14on Stability and Cleanliness of Liquid Fuels
13、.Current edition approved June 10, 2002. Published September 2002.2This 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 an al
14、ternative(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.4Annual Book of ASTM Standards, Vol 05.02.5Annual Book of ASTM Standards, Vol 14.04.1Copyright ASTM International, 100
15、 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.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
16、 method tests fuel under turbulent flow (highReynolds 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 b
17、e reduced manually or automatically, if required.5.4 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 contai
18、ned in the samplevessel is drawn through the sample 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 ou
19、ter surface to give ahigh thermal emissivity. The heating 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 ambien
20、t, as measured by the waste fuelelectronic thermometer, 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 whi
21、ch is located on a computer-controlled elevating platform.6.2 The thermal stability apparatus6and capillary tube6isspecified 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 Metho
22、dE 128.6.4 Sample Filter, 20-m stainless steel.6.5 Aeration 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 aera
23、te the test sample.7. Reagents and Materials7.1 Heptane, 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 trisolve
24、nt is flammable;harmful if inhaled; irritating to skin, 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
25、 Cleaning Solvent, technical grade, 95 % purity, forcleaning 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 i
26、ndicate the absorption of water by changes from blue 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 Contai
27、ners8.1 Obtain samples for testing in accordance with 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 closuressh
28、all be rinsed at least three times with the fuel being 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 recommen
29、ded, but when only usedcontainers are available, a thorough 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
30、/minfor 10 min.8.3 Sample SizeStandard operating conditions are: 3 L for13 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
31、may result in exposure to fuel orsolvent. It is recommended 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 c
32、heckthat the correct standard operating conditions are 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.6The equipment, a
33、s listed in the research report being prepared, was used todevelop the precision statement. The apparatus and capillary tubes described inAnnex A1 are both supplied by Stanhope-Seta, Chertsey, Surrey KT16 8AP, UK. Todate no other equipment has demonstrated through ASTM interlaboratory testing theabi
34、lity to meet the precision of this test. This is not an endorsement or certificationby ASTM. A research report is being prepared.D68110229.5 Commence the pre-test by installing a new capillarytube and carrying out the following in accordance with themanufacturers instructions.9.6 Immerse the input t
35、ube and sample filter in heptane.9.7 Clean the 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 Ch
36、eck the alignment and focus of the pyrometer and 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 F
37、low Rate, preset at 35 mL/min or as specified 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 cap
38、illary scan takes 5 min to complete.NOTE 4Other 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
39、 the apparatus arefollowed.11.2 Verify the performance 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 int
40、o a cleansample vessel filled with fuel aerated 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
41、bypass valve to TEST.NOTE 5The test can only start 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 fitting
42、s if necessary and repeat12.3.12.4 Close the capillary 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 th
43、e capillary tube, has stabilized to the prescribed 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 accordanc
44、ewith the manufacturers instructions. When this 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 TE
45、ST position.12.6 The result of the test is automatically 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
46、, along the surface of the capillary tube,during 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
47、 HiReTS Peak number is the largest of the differ-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
48、T65, T125,P65 and P125 to denote Total (T) or 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 anydevi
49、ation, 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 Bias615.1 The precision of this test method, as determined bystatistical analyses of interlaboratory results, is as follows:TABLE 1 Standard Instrument SettingsNOTE 1Tolerances for the instrument settings are given in Annex A1.NOTE 2The datum position is the bottom of the top bus bar connector.See Fig. A1.3.NOTE 3Touching the blacke
