ASTM D7665-22

This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Because
it may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current version
of the standard as published by ASTM is to be considered the official document.
Designation: D7665 − 17 D7665 − 22
Standard Guide for
Evaluation of Biodegradable Heat Transfer Fluids
This standard is issued under the fixed designation D7665; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope*
1.1 This guide covers general information, without specific limits, for selecting standard test methods for evaluating heat transfer
fluids for quality and aging. These test methods are considered particularly useful in characterizing biodegradable water-free heat
transfer fluids in closed systems.
1.2 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.
1.3 This international standard was developed in accordance with internationally recognized principles on standardization
established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued
by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
2. Referenced Documents
2.1 ASTM Standards:
D86 Test Method for Distillation of Petroleum Products and Liquid Fuels at Atmospheric Pressure
D91 Test Method for Precipitation Number of Lubricating Oils
D92 Test Method for Flash and Fire Points by Cleveland Open Cup Tester
D93 Test Methods for Flash Point by Pensky-Martens Closed Cup Tester
D95 Test Method for Water in Petroleum Products and Bituminous Materials by Distillation
D97 Test Method for Pour Point of Petroleum Products
D189 Test Method for Conradson Carbon Residue of Petroleum Products
D445 Test Method for Kinematic Viscosity of Transparent and Opaque Liquids (and Calculation of Dynamic Viscosity)
D471 Test Method for Rubber Property—Effect of Liquids
D524 Test Method for Ramsbottom Carbon Residue of Petroleum Products
D664 Test Method for Acid Number of Petroleum Products by Potentiometric Titration
D893 Test Method for Insolubles in Used Lubricating Oils
D1160 Test Method for Distillation of Petroleum Products at Reduced Pressure
D1298 Test Method for Density, Relative Density, or API Gravity of Crude Petroleum and Liquid Petroleum Products by
Hydrometer Method
D1500 Test Method for ASTM Color of Petroleum Products (ASTM Color Scale)
D2270 Practice for Calculating Viscosity Index from Kinematic Viscosity at 40 °C and 100 °C
This guide is under the jurisdiction of ASTM Committee D02 on Petroleum Products, Liquid Fuels, and Lubricants and is the direct responsibility of Subcommittee
D02.L0.06 on Non-Lubricating Process Fluids.
Current edition approved Aug. 1, 2017July 1, 2022. Published August 2017August 2022. Originally approved in 2010. Last previous edition approved in 20142017 as
D7665 – 10 (2014).D7665 – 17. DOI: 10.1520/D7665-17.10.1520/D7665-22.
The background for this standard was developed by a questionnaire circulated by ASTM-ASLE technical division L-VI-2 and reported in Lubrication Engineering, Vol
32, No. 8, August 1976, pp. 411–416.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM Standards
volume information, refer to the standard’s Document Summary page on the ASTM website.
*A Summary of Changes section appears at the end of this standard
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D7665 − 22
D2717 Test Method for Thermal Conductivity of Liquids (Withdrawn 2018)
D2766 Test Method for Specific Heat of Liquids and Solids (Withdrawn 2018)
D2879 Test Method for Vapor Pressure-Temperature Relationship and Initial Decomposition Temperature of Liquids by
Isoteniscope
D2887 Test Method for Boiling Range Distribution of Petroleum Fractions by Gas Chromatography
D4052 Test Method for Density, Relative Density, and API Gravity of Liquids by Digital Density Meter
D4175 Terminology Relating to Petroleum Products, Liquid Fuels, and Lubricants
D4530 Test Method for Determination of Carbon Residue (Micro Method)
D5864 Test Method for Determining Aerobic Aquatic Biodegradation of Lubricants or Their Components
D6384 Terminology Relating to Biodegradability and Ecotoxicity of Lubricants
D6743 Test Method for Thermal Stability of Organic Heat Transfer Fluids
D7042 Test Method for Dynamic Viscosity and Density of Liquids by Stabinger Viscometer (and the Calculation of Kinematic
Viscosity)
D7044 Specification for Biodegradable Fire Resistant Hydraulic Fluids
E659 Test Method for Autoignition Temperature of Chemicals
G4 Guide for Conducting Corrosion Tests in Field Applications
2.2 OECD Standards:
Test No. 203 : Fish, Acute Toxicity Test
3. Terminology
3.1 Definitions of Terms Specific to This Standard:
3.1.1 For definitions of terms used in this guide, refer to Terminology D4175.
3.1.2 fluid aging—aging, n—process of fluid degradation associated with the loss of intended performance of the fluid, which
includes fluid composition changes, soot formation, and the deposit of materials on a surface (fouling).
3.1.3 fluid quality—quality, n—describes the fluid’s appropriateness for the intended application including factors necessary for
safety and environmental awareness or compliance.
3.1.4 heat transfer fluid—fluid, n—fluid that remains essentially a liquid while transferring heat to or from an apparatus or process,
although this guide does not preclude the evaluation of a heat transfer fluid that may be used in its vapor state. Heat transfer fluids
may be hydrocarbon or petroleum based, such as polyglycols, esters, hydrogenated terphenyls, alkylated aromatics, diphenyl-
oxide/biphenyl blends, and mixtures of di- and triaryl-ethers. Small percentages of functional components such as antioxidants,
antiwear and anti-corrosion agents, TBN, acid scavengers, or dispersants, or a combination thereof, can be present.
4. Significance and Use
4.1 The significance of each test method depends upon the system in use and the purpose of the test method as listed under Section
5. Use the most recent editions of ASTM test methods.
5. Recommended Test Procedures
5.1 Pumpability of the Fluid:
5.1.1 Flash Point, Closed Cup (Test Method D93)—This test method detects low flash ends which are one cause of cavitation
during pumping. In closed systems, especially when fluids are exposed to temperatures of 225 °C or higher, the formation of
volatile hydrocarbons by breakdown of the oil may require venting through a pressure relief system to prevent dangerous pressure
build-up.
5.1.2 Pour Point (Test Method D97)—The pour point can be used as an approximate guide to the minimum temperature for normal
pumping and as a general indication of fluid type and low temperature properties. Should a heat transfer system be likely to be
subjected to low temperatures when not in use, the system should be trace heated to warm the fluid above minimum pumping
temperature before start-up.
The last approved version of this historical standard is referenced on www.astm.org.
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D7665 − 22
5.1.3 Viscosity (Test Method D445 or D7042)—Fluid viscosity is important for determining Reynolds and Prandtl numbers for heat
transfer systems, to estimate fluid turbulence, heat transfer coefficient, and heat flow. Generally, a fluid that is above approximately
200 cSt is difficult to pump. The pump and system design determine the viscosity limit required for pumping. The construction
of a viscosity/temperature curve using determined viscosities can be used to estimate minimum pumping temperature.
5.1.4 Specific Gravity (Test Method D1298 or D4052)—Hydraulic shock during pumping has been predicted via the use of a
combination of density and compressibility data.
5.1.5 Water Content (Test Method D95)—The water content of a fresh heat transfer fluid can be used to indicate how long the heat
transfer system shall be dried out during commissioning, while raising the bulk oil temperature through the 100 °C plus region,
with venting, before the system can be safely used at higher temperatures. The expansion tank should be full during the operations
to ensure that moisture is safely vented in the lowest pressure part of the systems. Positive nitrogen pressure on the heat exchange
systems minimizes entry of air or moisture. Heat transfer systems operating at temperatures of 120 °C or greater shall, for reasons
of safety, be dry, because destructive high pressures are generated when water enters the high temperature sections of the system.
Heating the oil before it is placed in service also removes most of the dissolved air in the oil. If not removed, the air can cause
pump cavitation. The air can also accumulate in sta
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