1、Designation: D7665 10Standard Guide forEvaluation of Biodegradable Heat Transfer Fluids1This standard is issued under the fixed designation D7665; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision. A number
2、in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope1.1 This guide2covers general information, without specificlimits, for selecting standard test methods for evaluating heattransfer fluids for qual
3、ity and aging. These test methods areconsidered particularly useful in characterizing biodegradablewater free heat transfer fluids in closed systems.1.2 The values stated in SI units are to be regarded asstandard. No other units of measurement are included in thisstandard.2. Referenced Documents2.1
4、ASTM Standards:3D86 Test Method for Distillation of Petroleum Products atAtmospheric PressureD91 Test Method for Precipitation Number of LubricatingOilsD92 Test Method for Flash and Fire Points by ClevelandOpen Cup TesterD93 Test Methods for Flash Point by Pensky-MartensClosed Cup TesterD95 Test Met
5、hod for Water in Petroleum Products andBituminous Materials by DistillationD97 Test Method for Pour Point of Petroleum ProductsD189 Test Method for Conradson Carbon Residue of Pe-troleum ProductsD445 Test Method for Kinematic Viscosity of Transparentand Opaque Liquids (and Calculation of Dynamic Vis
6、cos-ity)D471 Test Method for Rubber PropertyEffect of LiquidsD524 Test Method for Ramsbottom Carbon Residue ofPetroleum ProductsD664 Test Method for Acid Number of Petroleum Productsby Potentiometric TitrationD893 Test Method for Insolubles in Used Lubricating OilsD1160 Test Method for Distillation
7、of Petroleum Productsat Reduced PressureD1298 Test Method for Density, Relative Density (SpecificGravity), or API Gravity of Crude Petroleum and LiquidPetroleum Products by Hydrometer MethodD1500 Test Method forASTM Color of Petroleum Products(ASTM Color Scale)D2270 Practice for Calculating Viscosit
8、y Index from Kine-matic Viscosity at 40 and 100CD2717 Test Method for Thermal Conductivity of LiquidsD2766 Test Method for Specific Heat of Liquids and SolidsD2887 Test Method for Boiling Range Distribution ofPetroleum Fractions by Gas ChromatographyD2879 Test Method for Vapor Pressure-Temperature R
9、ela-tionship and Initial Decomposition Temperature of Liquidsby IsoteniscopeD4530 Test Method for Determination of Carbon Residue(Micro Method)D5864 Test Method for Determining Aerobic Aquatic Bio-degradation of Lubricants or Their ComponentsD6384 Terminology Relating to Biodegradability and Ec-otox
10、icity of LubricantsD6743 Test Method for Thermal Stability of Organic HeatTransfer FluidsD7044 Specification for Biodegradable Fire Resistant Hy-draulic FluidsE659 Test Method for Autoignition Temperature of LiquidChemicalsG4 Guide for Conducting Corrosion Tests in Field Applica-tions2.2 OECD Standa
11、rds:4Test No. 203 : Fish, Acute Toxicity Test3. Terminology3.1 Definitions of Terms Specific to This Standard:3.1.1 fluid agingprocess of fluid degradation associatedwith the loss of intended performance of the fluid, which1This guide is under the jurisdiction of ASTM Committee D02 on PetroleumProdu
12、cts and Lubricants and is the direct responsibility of Subcommittee D02.L0.06on Non-Lubricating Process Fluids.Current edition approved Oct. 1, 2010. Published October 2010. DOI: 10.1520/D7665-10.2The background for this standard was developed by a questionnaire circulatedby ASTM-ASLE technical divi
13、sion L-VI-2 and reported in Lubrication Engineer-ing, Vol 32, No. 8, August 1976, pp. 411416.3For 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
14、Summary page onthe ASTM website.4Organisation for Economic Co-operation and Development (OECD), 2, rueAndr Pascal, 75775 Paris Cedex 16, France.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.includes fluid composition changes, soot
15、formation, and thedeposit of materials on a surface (fouling).3.1.2 fluid qualitydescribes the fluids appropriateness forthe intended application including factors necessary for safetyand environmental awareness or compliance.3.1.3 heat transfer fluidfluid that remains essentially aliquid while tran
16、sferring heat to or from an apparatus orprocess, although this guide does not preclude the evaluation ofa heat transfer fluid that may be used in its vapor state. Heattransfer fluids may be hydrocarbon or petroleumbased, suchas polyglycols, esters, hydrogenated terphenyls, alkylated aro-matics, diph
17、enyl-oxide/biphenyl blends, and mixtures of di-and triaryl-ethers. Small percentages of functional componentssuch as antioxidants, antiwear and anti-corrosion agents, TBN,acid scavengers, or dispersants, or a combination thereof, canbe present.4. Significance and Use4.1 The significance of each test
18、 method depends upon thesystem in use and the purpose of the test method as listed underSection 5. Use the most recent editions of ASTM test methods.5. Recommended Test Procedures5.1 Pumpability of the Fluid:5.1.1 Flash Point, Closed Cup (Test Method D93)Thistest method detects low flash ends which
19、are one cause ofcavitation during pumping. In closed systems, especially whenfluids are exposed to temperatures of 225C or higher, theformation of volatile hydrocarbons by breakdown of the oilmay require venting through a pressure relief system to preventdangerous pressure build-up.5.1.2 Pour Point
20、(Test Method D97)The pour point can beused as an approximate guide to the minimum temperature fornormal pumping and as a general indication of fluid type andlow temperature properties. Should a heat transfer system belikely to be subjected to low temperatures when not in use, thesystem should be tra
21、ce heated to warm the fluid aboveminimum pumping temperature before start-up.5.1.3 Viscosity (Test Method D445)Fluid viscosity is im-portant for determining Reynolds and Prandtl numbers for heattransfer systems, to estimate fluid turbulence, heat transfercoefficient, and heat flow. Generally, a flui
22、d that is aboveapproximately 200 cSt is difficult to pump. The pump andsystem design determine the viscosity limit required forpumping. The construction of a viscosity/temperature curveusing determined viscosities can be used to estimate minimumpumping temperature.5.1.4 Specific Gravity (Test Method
23、 D1298)Hydraulicshock during pumping has been predicted via the use of acombination of density and compressibility data.5.1.5 Water Content (Test Method D95)The water contentof a fresh heat transfer fluid can be used to indicate how longthe heat transfer system shall be dried out during commission-i
24、ng, while raising the bulk oil temperature through the 100Cplus region, with venting, before the system can be safely usedat higher temperatures. The expansion tank should be fullduring the operations to ensure that moisture is safely vented inthe lowest pressure part of the systems. Positive nitrog
25、enpressure on the heat exchange systems minimizes entry of airor moisture. Heat transfer systems operating at temperatures of120C or greater shall, for reasons of safety, be dry, becausedestructive high pressures are generated when water enters thehigh temperature sections of the system. Heating the
26、 oil beforeit is placed in service also removes most of the dissolved air inthe oil. If not removed, the air can cause pump cavitation. Theair can also accumulate in stagnant parts of the system at highpressure and could cause an explosion.5.1.6 Vapor Pressure (Test Method D2879)Vapor pres-sure, whi
27、ch normally increases with increasing operatingtemperature, is an important design parameter. Organic heattransfer fluids exhibiting high vapor pressures should be usedonly in systems with sufficient structural integrity. Operation ofvapor phase systems requires knowledge of the equilibriumvapor pre
28、ssure.5.2 Safety in Use:5.2.1 Autoignition Temperature (Test Method E659)Thistest relates to the autoignition temperature of a bulk fluid.Hydrocarbon fluids absorbed on porous inert surfaces canignite at temperatures more than 50C lower than indicated byTest Method E659. An open flame ignites leakin
29、g hydrocarbonfluids exposed on a porous surface at any temperature.5.2.2 Flash Point (Test Methods D92 and D93)Some heattransfer fluids are volatile and present a fire hazard at slightlyelevated temperatures, or even below 25C.5.2.3 Biodegradation (Test Method D5864)5An environ-mental concern, and t
30、oxicity (like acute fish toxicity, seeOECD Test No. 203) is more of an immediate concern forpersonnel that may come into contact with the heat transferfluid as well as plant and animal life that may come into contactwith effluent that migrates to streams, rivers, or reservoirs.Safety in use informat
31、ion is included a Material Safety DataSheet (MSDS). See Terminology D6384 for terminologyrelating to biodegradability and ecotoxicity. A basis for biode-gradable classification for hydraulic fluids is found in Table 4of D7044-04 and while no specific biodegradability classifica-tions are available f
32、or heat transfer fluids, the environmentalpersistence of heat transfer fluids should be evaluated.5.3 Effect on Equipment:5.3.1 Effect on Rubber or Elastomeric Seals (Test MethodD471)Most seals in heat exchange equipment are made ofsteel or other metal. If rubber seals are present, it is desirableto
33、 maintain rubber swelling in the range of 1 to5%topreventleakage because of poor seal contact. Seals may degrade insome fluids. As an oil deteriorates in service, additional testsmay be required to ensure that seals remain compatible withthe altered oil. The temperature ranges of the tests shouldcor
34、respond to temperatures to which seals will be exposed inservice.5.3.2 Corrosion (Guide G4)These tests concern selectionof materials of construction with fluids usable for heat transfersystems. Guide G4 uses test metal specimens fixed within thestream of test fluid under use. The specimens and condi
35、tionsfor test shall be specified for each system.5As heat transfer fluids are mainly used in closed and sealed circuits, this guideis limited to biodegradation issues. An extension to “environmentally friendly” or“ecoevaluated” heat transfer fluids including aquatic toxicities may be an object offut
36、ure revision.D7665 1025.4 Effciency:5.4.1 Thermal Conductivity (Test Method D2717) and Spe-cific Heat (Test Method D2766)These thermal conductivityand specific heat tests are difficult to carry out, facilities forperforming them are few, and the precision data is yet to beestablished. Values can be
37、estimated for design use from thegeneral chemical composition. Differences contribute to effi-ciency to a lesser degree than values such as viscosity, moisturecontamination, and other measurable values in 5.1 and 5.5 ofthis guide. The values for thermal conductivity and specificheat may be available
38、 from the fluid supplier.65.5 Service Life:5.5.1 Thermal Stability, Laboratory Tests7Thermal stabil-ity is here defined as the resistance of a hydrocarbon liquid topermanent changes in properties that make it a less efficientheat transfer fluid. These changes may be related to alterationsin the liqu
39、ids properties, such as viscosity, or to the tendencyto foul heat exchanger surfaces with insulating deposits.Normally, testing should be done in the absence of air andmoisture to stimulate “tight” systems. The test may be usefulfor assessing the remaining service life of a used fluid, or itmay be u
40、sed to compare the expected service life of competi-tive new heat transfer fluids.5.5.2 The following test methods can be used to determinethe change in values between new and used fluids, or betweena fluid before and after subjection to a laboratory thermalstability test. These test methods have be
41、en found especiallyuseful for determining the end of a fluids service life when anidentical fluid has been monitored with the same tests through-out its service life. These test methods can also detect leakageof foreign material into the heat transfer fluid.5.5.2.1 Precipitation Number (Test Method
42、D91) and In-solubles (Test Method D893)These test methods determinethe extent to which insolubles that may contribute to fouling ofmetal surfaces are increasing.5.5.2.2 Flash Point (Test Methods D92 and D93)A low-ering of flash point is indicative of thermal cracking to producelower molecular weight
43、 hydrocarbons. A rapid increase mayindicate that fluid is being exposed to excessive temperatures.5.5.2.3 Carbon Residue (Test Methods D189, D524, andD4530)An increase of carbon residue during service pro-vides an indication of the fluids tendency to form carbon-aceous deposits. These deposits, whic
44、h may impair heattransfer, are caused by precipitation of high molecular weightmaterials produced by thermal cracking of the fluid.5.5.2.4 Viscosity (Test Method D445)An increase in vis-cosity may reduce the fluids ability to transfer heat (see 5.1.3).Cracking of hydrocarbons in high temperature ser
45、vice in closedsystems often causes a decrease in viscosity. Thus a change inviscosity taken by itself is insufficient to judge the performanceof a fluid in service.5.5.2.5 Distillation (Test Methods D86, D1160, andD2887)Distillation can show directly the percentage of afluid that has cracked into lo
46、wer boiling products or has beenconverted into higher boiling products. Distillation data canserve as the sole criterion for changing a heat transfer fluid.5.5.2.6 Neutralization Number (Test Method D664)Amarked increase in neutralization number is a warning ofoxidation in the system, which may be t
47、he result of leaks. Inhigh-temperature service (200C), organic acids may decom-pose, and the use of infrared analyses may serve as a morereliable method for detection of oxidation.5.5.2.7 Color (Test Method D1500)In itself, color is notimportant, but may be the initial indication of chemicalchanges
48、in the heat transfer system.5.5.2.8 Viscosity Index (Test Method D2270)The viscosityindex of a fluid may change during service. Generally, theviscosity of a heat transfer fluid is not measured at theoperating temperature (see 5.5.2.4). If the viscosity index ofnew and used fluids are known, the visc
49、osities at operatingtemperature can be estimated and compared.5.5.2.9 Water Content (Test Method D95)Small amountsof water present in heat transfer systems may cause corrosion,high pressures, or pump cavitation.6. Keywords6.1 biodegradable; characterization; heat transfer fluid; heattransfer oil; heat transfer systemASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this standard. Users of this standard are expressly advised that determination of the validity of a
