ASTM D1903-08(2017)

Standard Practice for Determining the Coefficient of Thermal Expansion of Electrical Insulating Liquids of Petroleum Origin, and Askarels

SIGNIFICANCE AND USE
4.1 Knowledge of the coefficient of thermal expansion of a liquid is essential to compute the required size of a container to accommodate a volume of liquid over the full temperature range to which it will be subjected. It is also used to compute the volume of void space that would exist in an inelastic device filled with the liquid after the liquid has cooled to a lower temperature.
SCOPE
1.1 This practice covers the determination of the coef-ficient of thermal expansion of electrical insulating liquids of petroleum origin, and askarels, containing PCBs (polychlorinated biphenyls), when used as an insulating or cooling medium, or both, in cables, transformers, oil circuit breakers, capacitors, or similar apparatus.  
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 standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

General Information

• Status: Published
• Publication Date: 31-Dec-2016
• ICS: 29.040.10 - Insulating oils
• Technical Committee: D27 - Electrical Insulating Liquids and Gases
• Drafting Committee: D27.07 - Physical Test

Relations

• Replaces: ASTM D1903-08 - Standard Practice for Determining the Coefficient of Thermal Expansion of Electrical Insulating Liquids of Petroleum Origin, and Askarels
• Effective Date: 01-Jan-2017
• Refers: ASTM D1250-19e1 - Standard Guide for the Use of the Joint API and ASTM Adjunct for Temperature and Pressure Volume Correction Factors for Generalized Crude Oils, Refined Products, and Lubricating Oils: API MPMS Chapter 11.1
• Effective Date: 01-May-2019
• Refers: ASTM D1298-12a - Standard Test Method for Density, Relative Density (Specific Gravity), or API Gravity of Crude Petroleum and Liquid Petroleum Products by Hydrometer Method
• Effective Date: 15-May-2012
• Refers: ASTM D1298-12 - Standard Test Method for Density, Relative Density (Specific Gravity), or API Gravity of Crude Petroleum and Liquid Petroleum Products by Hydrometer Method
• Effective Date: 01-Apr-2012
• Refers: ASTM D1250-07 - Standard Guide for Use of the Petroleum Measurement Tables
• Effective Date: 01-May-2007
• Refers: ASTM D1298-99(2005) - Standard Test Method for Density, Relative Density (Specific Gravity), or API Gravity of Crude Petroleum and Liquid Petroleum Products by Hydrometer Method
• Effective Date: 01-Nov-2005
• Refers: ASTM D1250-04 - Standard Guide for Use of the Petroleum Measurement Tables
• Effective Date: 01-May-2004
• Refers: ASTM D1250-80(2002) - Standard Guide for Petroleum Measurement Tables
• Effective Date: 10-Dec-2002
• Refers: ASTM D1298-99 - Standard Test Method for Density, Relative Density (Specific Gravity), or API Gravity of Crude Petroleum and Liquid Petroleum Products by Hydrometer Method
• Effective Date: 10-Jun-1999
• Refers: ASTM D1298-99e2 - Standard Test Method for Density, Relative Density (Specific Gravity), or API Gravity of Crude Petroleum and Liquid Petroleum Products by Hydrometer Method
• Effective Date: 10-Jun-1999
• Refers: ASTM D1298-99e1 - Standard Test Method for Density, Relative Density (Specific Gravity), or API Gravity of Crude Petroleum and Liquid Petroleum Products by Hydrometer Method
• Effective Date: 10-Jun-1999
• Refers: ASTM D1250-80(1997)e1 - Standard Guide for Petroleum Measurement Tables
• Effective Date: 01-Jan-1997
• Referred By: ASTM D117-22 - Standard Guide for Sampling, Test Methods, and Specifications for Electrical Insulating Liquids
• Effective Date: 01-Jan-2017
• Referred By: ASTM D3487-16e1 - Standard Specification for Mineral Insulating Oil Used in Electrical Apparatus
• Effective Date: 01-Jan-2017
• Referred By: ASTM D6871-17 - Standard Specification for Natural (Vegetable Oil) Ester Fluids Used in Electrical Apparatus
• Effective Date: 01-Jan-2017

Overview

ASTM D1903-08(2017): Standard Practice for Determining the Coefficient of Thermal Expansion of Electrical Insulating Liquids of Petroleum Origin, and Askarels establishes practical guidelines for assessing the thermal expansion properties of petroleum-based insulating liquids and askarels containing PCBs. These fluids are widely used in critical electrical apparatus such as cables, transformers, circuit breakers, and capacitors, where stability under temperature changes is essential for performance and safety.

This standard provides methodologies for quantifying the change in volume per unit volume per degree temperature change, enabling accurate calculation of container or device size requirements over various temperature conditions. All measurements are to be reported in SI units, ensuring international consistency.

Key Topics

• Coefficient of Thermal Expansion: The document defines and outlines procedures for determining how much insulating liquids expand or contract with temperature fluctuations.
• Applicability to Petroleum-Based Insulating Liquids and Askarels: Coverage includes both petroleum-derived fluids and askarels (liquids containing polychlorinated biphenyls, PCBs), which are common in electrical systems.
• Measurement Methods: The standard relies on established ASTM procedures for measuring specific gravity at different temperatures, referencing complementary standards such as ASTM D1298 and, for askarels, ASTM D1810 or D941.
• Calculation: The coefficient is calculated as the difference in relative density (or specific gravity) at two temperatures, divided by the product of the lower temperature’s density and the temperature difference.
• Safety Considerations: The standard emphasizes user responsibility for implementing appropriate safety practices and regulatory compliance.

Applications

Accurate determination of the coefficient of thermal expansion for electrical insulating liquids has several crucial applications:

• Electrical Equipment Design: Engineers use this data to specify container size or expansion systems within transformers, capacitors, and oil circuit breakers, ensuring safe operation across expected temperature ranges.
• Volume Compensation: Calculation of void spaces in inelastic containers filled with insulating liquids helps prevent issues such as leakage or mechanical stress resulting from temperature-induced volume changes.
• Operational Reliability: Proper application of this standard helps maintain the insulating and cooling integrity of electrical devices, minimizing failure risks and extending service life.
• Regulatory Compliance: Measurement practices outlined in ASTM D1903-08(2017) support adherence to international industry requirements and facilitate acceptance in global markets.

Related Standards

ASTM D1903-08(2017) is part of a suite of standards relevant to electrical insulating fluids and their properties:

• ASTM D1250: Guide for Use of the Petroleum Measurement Tables - often used for determining properties of petroleum products.
• ASTM D1298: Test Method for Density, Relative Density, or API Gravity of Crude Petroleum and Liquid Petroleum Products by Hydrometer Method.
• ASTM D1810: Test Method for Specific Gravity of Askarels (withdrawn but referenced for legacy applications).
• ASTM D941: Test Method for Density and Relative Density (Specific Gravity) of Liquids by Lipkin Bicapillary Pycnometer (withdrawn, but referenced for certain measurements).

Employing ASTM D1903-08(2017) ensures consistent, internationally recognized measurements of the thermal expansion properties of electrical insulating liquids, supporting safe, efficient, and reliable power system operations.

Keywords: coefficient of thermal expansion, electrical insulating liquids, petroleum, askarels, PCBs, ASTM D1903, specific gravity, temperature, volume, electrical transformers, capacitors, oil circuit breakers

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: D1903 − 08 (Reapproved 2017)
Standard Practice for
Determining the Coefficient of Thermal Expansion of
Electrical Insulating Liquids of Petroleum Origin, and
Askarels
This standard is issued under the fixed designation D1903; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision.Anumber in parentheses indicates the year of last reapproval.A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope 3.1.1 coeffıcient of thermal expansion of a liquid, n—the
change in volume per unit volume per degree change in
1.1 Thispracticecoversthedeterminationofthecoef-ficient
temperature. It is commonly stated as the average coefficient
of thermal expansion of electrical insulating liquids of petro-
over a given temperature range.
leum origin, and askarels, containing PCBs (polychlorinated
biphenyls), when used as an insulating or cooling medium, or
4. Significance and Use
both,incables,transformers,oilcircuitbreakers,capacitors,or
4.1 Knowledge of the coefficient of thermal expansion of a
similar apparatus.
liquidisessentialtocomputetherequiredsizeofacontainerto
1.2 The values stated in SI units are to be regarded as
accommodate a volume of liquid over the full temperature
standard. No other units of measurement are included in this
range to which it will be subjected. It is also used to compute
standard.
thevolumeofvoidspacethatwouldexistinaninelasticdevice
1.3 This standard does not purport to address all of the
filled with the liquid after the liquid has cooled to a lower
safety concerns, if any, associated with its use. It is the
temperature.
responsibility of the user of this standard to establish appro-
5. Procedure for Liquids of Petroleum Origin
priate safety and health practices and determine the applica-
bility of regulatory limitations prior to use.
5.1 The coefficient of thermal expansion used in Guide
D1250, is 0.00040/°F for the temperature range from−17.7 to
2. Referenced Documents
65.5°C (0 to 150°F), and petroleum oils ranging from 15.0 to
2.1 ASTM Standards:
34.9°APIgravityor0.9659to0.8504relativedensity(specific
D941Test Method for Density and Relative Density (Spe-
gravity). In the preparation of these tables for relative density
cific Gravity) of Liquids by Lipkin Bicapillary Pycnom-
(specific gravity) values above 0.600, it has been assumed for
eter (Withdrawn 1993)
purposes of standardization that all crude petroleum and
D1250Guide for Use of the Petroleum Measurement Tables
petroleum products have uniform coefficients of expansion in
D1298Test Method for Density, Relative Density, or API
the same temperature ranges. When the required accuracy of
Gravity of Crude Petroleum and Liquid Petroleum Prod-
results falls within these assumptions, this value for coefficient
ucts by Hydrometer Method
of expansion may be used.
D1810Test Method for Specific Gravity of Askarels (With-
3 5.2 If closer approximation than that indicated in 5.1 is
drawn 2001)
required, the coefficient of thermal expansion may be calcu-
3. Terminology lated by determining observed relative densities (specific
gravities).Determinetherelativedensitiesatanytwotempera-
3.1 Definitions of Terms Specific to This Standard:
tures below 90°C (194°F) and not less than 5°C (9°F), nor
more than 14°C (25°F) degrees apart by Practice D1298. The
This practic
...