ASTM D4652-20
(Specification)Standard Specification for Silicone Liquid Used for Electrical Insulation
Standard Specification for Silicone Liquid Used for Electrical Insulation
ABSTRACT
This specification covers silicone fluid, polydimethylsiloxane, for use in transformers, capacitors, and electronic assemblies as an insulating or cooling medium, or both. Physical, electrical, and chemical tests shall be conducted on the specimen to check for quality conformance. The silicone fluid shall conform to the color, flash point, fire point, pour point, refractive index, viscosity, specific gravity, weight of volatile matter, dielectric breakdown, disk electrodes, VDE electrodes, dissipation factor, volume resistivity, neutralization number, water content, and PCB content requirements.
SCOPE
1.1 This specification covers silicone liquid for use in transformers, capacitors, and electronic assemblies as an insulating or cooling medium, or both.
1.2 Silicone liquid covered by this specification is polydimethylsiloxane having a nominal viscosity of 50 mm2/s at 25°C and a fire point of 340°C or greater. This specification applies only to new silicone liquid. Information on in-service maintenance testing is available in appropriate guides.2
1.3 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.
1.4 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.
General Information
- Status
- Published
- Publication Date
- 31-Oct-2020
- Technical Committee
- D27 - Electrical Insulating Liquids and Gases
- Drafting Committee
- D27.02 - Gases and Non-Mineral Oil Liquids
Relations
- Effective Date
- 01-Apr-2024
- Effective Date
- 01-Dec-2023
- Effective Date
- 01-Dec-2023
- Effective Date
- 01-Nov-2023
- Effective Date
- 01-Oct-2019
- Effective Date
- 01-Oct-2019
- Effective Date
- 01-Apr-2019
- Effective Date
- 01-Dec-2018
- Effective Date
- 01-Jun-2017
- Effective Date
- 01-May-2017
- Effective Date
- 01-Mar-2017
- Effective Date
- 01-Feb-2017
- Effective Date
- 01-Jan-2017
- Effective Date
- 15-Dec-2016
- Effective Date
- 01-Oct-2015
Overview
ASTM D4652-20: Standard Specification for Silicone Liquid Used for Electrical Insulation provides comprehensive requirements for new, unused silicone fluids-specifically polydimethylsiloxane-utilized as insulating and/or cooling media in electrical systems. Developed by ASTM International, this standard ensures the consistent quality and safety of silicone liquids used in transformers, capacitors, and electronic assemblies. By defining essential physical, electrical, and chemical criteria, ASTM D4652-20 supports reliability and operational efficiency in industrial, energy, and electronic sectors where electrical insulation is crucial.
Silicone insulating liquids covered by this standard must possess a nominal viscosity of 50 mm²/s at 25°C and a fire point of at least 340°C, ensuring robust thermal and electrical performance. This specification applies exclusively to new silicone liquids, with guidance available elsewhere for in-service maintenance testing.
Key Topics
- Material Requirements
- Covers only new, unused polydimethylsiloxane silicone fluid.
- Specifies viscosity, fire point, and other critical physical properties.
- Quality Criteria
- Defines acceptance levels for physical, electrical, and chemical characteristics including:
- Color and clarity
- Flash and fire point
- Pour point (low temperature flow capability)
- Viscosity at multiple temperatures
- Specific gravity and refractive index
- Weight of volatile matter and water content
- Dielectric breakdown voltage (using both disk and VDE electrodes)
- Dissipation factor and volume resistivity
- Neutralization number (acidity/alkalinity control)
- Non-detectable PCB content for environmental compliance
- Defines acceptance levels for physical, electrical, and chemical characteristics including:
- Testing and Compliance
- Calls for testing using referenced ASTM methods such as D445 for viscosity, D92 for flash point, D877 and D1816 for dielectric breakdown, and D1533 for water content.
- Sampling and test methods are detailed to ensure reliable, standardized measurement processes.
- International Alignment
- Developed in accordance with WTO TBT Committee principles, facilitating global acceptance and compliance.
Applications
ASTM D4652-20 is widely applied wherever electrical equipment requires robust liquid insulation or heat management under stringent conditions:
- Transformers
Ensures transformer safety and efficiency by maintaining high dielectric strength, thermal stability, and low water content. - Capacitors
Provides reliable insulation, reduces losses, and extends equipment life by minimizing chemical reactivity and improving electrical resistivity. - Electronic Assemblies
Supports compact, high-reliability electronic assemblies by managing thermal loads and preventing electrical breakdowns. - Industrial and Utility Equipment
Used in high-voltage and specialized environments where superior dielectric performance and fire safety are required.
Using silicone liquids that meet ASTM D4652-20 helps manufacturers, utilities, and maintenance providers achieve regulatory compliance, minimize failures, and ensure environmentally safe operations.
Related Standards
Several ASTM and industry standards complement ASTM D4652-20 for silicone liquid insulation applications:
- ASTM D2225 - Test Methods for Silicone Fluids Used for Electrical Insulation
- ASTM D877, D1816 - Dielectric Breakdown Voltage Test Methods
- ASTM D445, D2161 - Viscosity Measurement
- ASTM D1533 - Water in Insulating Liquids
- ASTM D4059 - PCB Content Analysis
- IEEE C57.111 - Guide for Acceptance and Maintenance of Silicone Insulating Fluid in Transformers
Together, these standards create a robust framework for testing, selecting, and managing electrical insulating liquids, supporting global safety and performance in power and electronic systems.
Keywords: ASTM D4652-20, silicone liquid, electrical insulation, transformer oil, polydimethylsiloxane, dielectric fluid, insulating liquid, ASTM standard, electronic assembly insulation, PCB-free insulating fluid.
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Frequently Asked Questions
ASTM D4652-20 is a technical specification published by ASTM International. Its full title is "Standard Specification for Silicone Liquid Used for Electrical Insulation". This standard covers: ABSTRACT This specification covers silicone fluid, polydimethylsiloxane, for use in transformers, capacitors, and electronic assemblies as an insulating or cooling medium, or both. Physical, electrical, and chemical tests shall be conducted on the specimen to check for quality conformance. The silicone fluid shall conform to the color, flash point, fire point, pour point, refractive index, viscosity, specific gravity, weight of volatile matter, dielectric breakdown, disk electrodes, VDE electrodes, dissipation factor, volume resistivity, neutralization number, water content, and PCB content requirements. SCOPE 1.1 This specification covers silicone liquid for use in transformers, capacitors, and electronic assemblies as an insulating or cooling medium, or both. 1.2 Silicone liquid covered by this specification is polydimethylsiloxane having a nominal viscosity of 50 mm2/s at 25°C and a fire point of 340°C or greater. This specification applies only to new silicone liquid. Information on in-service maintenance testing is available in appropriate guides.2 1.3 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard. 1.4 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.
ABSTRACT This specification covers silicone fluid, polydimethylsiloxane, for use in transformers, capacitors, and electronic assemblies as an insulating or cooling medium, or both. Physical, electrical, and chemical tests shall be conducted on the specimen to check for quality conformance. The silicone fluid shall conform to the color, flash point, fire point, pour point, refractive index, viscosity, specific gravity, weight of volatile matter, dielectric breakdown, disk electrodes, VDE electrodes, dissipation factor, volume resistivity, neutralization number, water content, and PCB content requirements. SCOPE 1.1 This specification covers silicone liquid for use in transformers, capacitors, and electronic assemblies as an insulating or cooling medium, or both. 1.2 Silicone liquid covered by this specification is polydimethylsiloxane having a nominal viscosity of 50 mm2/s at 25°C and a fire point of 340°C or greater. This specification applies only to new silicone liquid. Information on in-service maintenance testing is available in appropriate guides.2 1.3 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard. 1.4 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.
ASTM D4652-20 is classified under the following ICS (International Classification for Standards) categories: 29.035.20 - Plastics and rubber insulating materials; 71.100.55 - Silicones. The ICS classification helps identify the subject area and facilitates finding related standards.
ASTM D4652-20 has the following relationships with other standards: It is inter standard links to ASTM D445-24, ASTM D923-15(2023), ASTM D924-23, ASTM D445-23, ASTM D1169-19a, ASTM D1816-12(2019), ASTM D1169-19, ASTM D4059-00(2018), ASTM D1481-17, ASTM D664-11a(2017), ASTM D2864-17a, ASTM D2864-17, ASTM D2129-17, ASTM D445-16, ASTM D923-15. Understanding these relationships helps ensure you are using the most current and applicable version of the standard.
ASTM D4652-20 is available in PDF format for immediate download after purchase. The document can be added to your cart and obtained through the secure checkout process. Digital delivery ensures instant access to the complete standard document.
Standards Content (Sample)
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.
Designation:D4652 −20
Standard Specification for
Silicone Liquid Used for Electrical Insulation
This standard is issued under the fixed designation D4652; 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 D923 Practices for Sampling Electrical Insulating Liquids
D924 Test Method for Dissipation Factor (or Power Factor)
1.1 This specification covers silicone liquid for use in
and Relative Permittivity (Dielectric Constant) of Electri-
transformers, capacitors, and electronic assemblies as an insu-
cal Insulating Liquids
lating or cooling medium, or both.
D974 Test Method for Acid and Base Number by Color-
1.2 Silicone liquid covered by this specification is polydim-
Indicator Titration
ethylsiloxane having a nominal viscosity of 50 mm /s at 25°C
D1169 Test Method for Specific Resistance (Resistivity) of
and a fire point of 340°C or greater. This specification applies
Electrical Insulating Liquids
only to new silicone liquid. Information on in-service mainte-
D1298 Test Method for Density, Relative Density, or API
nance testing is available in appropriate guides.
Gravity of Crude Petroleum and Liquid Petroleum Prod-
1.3 The values stated in SI units are to be regarded as ucts by Hydrometer Method
D1481 Test Method for Density and Relative Density (Spe-
standard. No other units of measurement are included in this
standard. cific Gravity) of Viscous Materials by Lipkin Bicapillary
Pycnometer
1.4 This international standard was developed in accor-
D1533 Test Method for Water in Insulating Liquids by
dance with internationally recognized principles on standard-
Coulometric Karl Fischer Titration
ization established in the Decision on Principles for the
D1807 Test Methods for Refractive Index and Specific
Development of International Standards, Guides and Recom-
Optical Dispersion of Electrical Insulating Liquids (With-
mendations issued by the World Trade Organization Technical
drawn 2014)
Barriers to Trade (TBT) Committee.
D1816 Test Method for Dielectric Breakdown Voltage of
2. Referenced Documents Insulating Liquids Using VDE Electrodes
3 D2129 Test Method for Color of Clear Electrical Insulating
2.1 ASTM Standards:
Liquids (Platinum-Cobalt Scale)
D92 Test Method for Flash and Fire Points by Cleveland
D2225 Test Methods for Silicone Fluids Used for Electrical
Open Cup Tester
Insulation
D97 Test Method for Pour Point of Petroleum Products
D2864 Terminology Relating to Electrical Insulating Liq-
D445 Test Method for Kinematic Viscosity of Transparent
uids and Gases
and Opaque Liquids (and Calculation of Dynamic Viscos-
D4052 Test Method for Density, Relative Density, and API
ity)
Gravity of Liquids by Digital Density Meter
D664 Test Method for Acid Number of Petroleum Products
D4059 Test Method for Analysis of Polychlorinated Biphe-
by Potentiometric Titration
nyls in Insulating Liquids by Gas Chromatography
D877 Test Method for Dielectric Breakdown Voltage of
D4559 Test Method for Volatile Matter in Silicone Fluid
Insulating Liquids Using Disk Electrodes
3. Terminology
This specification is under the jurisdiction of ASTM Committee D27 on
3.1 Definitions and descriptions of terms specific to this
Electrical Insulating Liquids and Gasesand is the direct responsibility of Subcom-
specification are given in Test Methods D2225 and Terminol-
mittee D27.02 on Gases and Non-Mineral Oil Liquids.
ogy D2864.
Current edition approved Nov. 1, 2020. Published November 2020. Originally
approved in 1992. Last previous edition approved in 2012 as D4652 – 05(2012).
4. Sampling and Testing
DOI: 10.1520/D4652-20.
IEEE C57.111, IEEE Guide forAcceptance of Silicone Insu
...
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: D4652 − 05 (Reapproved 2012) D4652 − 20
Standard Specification for
Silicone FluidLiquid Used for Electrical Insulation
This standard is issued under the fixed designation D4652; 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 specification covers silicone fluidliquid for use in transformers, capacitors, and electronic assemblies as an insulating or
cooling medium, or both.
1.2 Silicone fluidliquid covered by this specification is polydimethylsiloxane having a nominal viscosity of 50 cStmm /s at 25°C
and a fire point of 340°C or greater. This specification applies only to new silicone fluid.liquid. Information on in-service
maintenance testing is available in appropriate guides.
1.3 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.
1.4 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:
D92 Test Method for Flash and Fire Points by Cleveland Open Cup Tester
D97 Test Method for Pour Point of Petroleum Products
D445 Test Method for Kinematic Viscosity of Transparent and Opaque Liquids (and Calculation of Dynamic Viscosity)
D664 Test Method for Acid Number of Petroleum Products by Potentiometric Titration
D877 Test Method for Dielectric Breakdown Voltage of Insulating Liquids Using Disk Electrodes
D923 Practices for Sampling Electrical Insulating Liquids
D924 Test Method for Dissipation Factor (or Power Factor) and Relative Permittivity (Dielectric Constant) of Electrical
Insulating Liquids
D974 Test Method for Acid and Base Number by Color-Indicator Titration
D1169 Test Method for Specific Resistance (Resistivity) of Electrical Insulating Liquids
D1298 Test Method for Density, Relative Density, or API Gravity of Crude Petroleum and Liquid Petroleum Products by
Hydrometer Method
D1481 Test Method for Density and Relative Density (Specific Gravity) of Viscous Materials by Lipkin Bicapillary Pycnometer
D1533 Test Method for Water in Insulating Liquids by Coulometric Karl Fischer Titration
This specification is under the jurisdiction of ASTM Committee D27 on Electrical Insulating Liquids and Gasesand is the direct responsibility of Subcommittee D27.02
on Gases and Non-Mineral Oil Liquids.
Current edition approved Oct. 15, 2012Nov. 1, 2020. Published October 2012November 2020. Originally approved in 1992. Last previous edition approved in 20052012
as D4652 – 05.D4652 – 05(2012). DOI: 10.1520/D4652-05R12.10.1520/D4652-20.
IEEE C57.111, IEEE Guide for Acceptance of Silicone Insulating Fluid and its Maintenance in Transformers is published by the Insulating Fluids Subcommittee of the
IEEE Power Engineering Society Transformers Committee.
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.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D4652 − 20
D1807 Test Methods for Refractive Index and Specific Optical Dispersion of Electrical Insulating Liquids (Withdrawn 2014)
D1816 Test Method for Dielectric Breakdown Voltage of Insulating Liquids Using VDE Electrodes
D2129 Test Method for Color of Clear Electrical Insulating Liquids (Platinum-Cobalt Scale)
D2161 Practice for Conversion of Kinematic Viscosity to Saybolt Universal Viscosity or to Saybolt
...
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