ASTM D1698-03

Standard Test Method for Sediments and Soluble Sludge in Service-Aged Insulating Oils

SIGNIFICANCE AND USE
Sediment in insulating oil may deposit on transformer parts and interfere with heat transfer and may choke oil ducts; thus hindering oil circulation and heat dissipation. Inorganic sediment usually indicates contamination of some type and organic sediment indicates either deterioration of the oil or contamination.
Soluble sludge indicates deterioration of the oil, presence of contaminants, or both. It serves as a warning that formation of sediment may be imminent.
The determination of sediment and soluble sludge in a used insulating oil assists in deciding whether the oil may continue to be used in its existing condition or should be replaced, reclaimed, or reconditioned.
SCOPE
1.1 This test method covers the determination of sediment and soluble sludge in service-aged insulating oils of petroleum origin. Also, provision is made for determining organic and inorganic content of the sediment. The method is intended primarily for oils of comparatively low viscosity; for example 5.7 to 13.0 cSt (mm²/s) at 40°C (104°F). Suitability for high viscosity oils have not been determined.
1.2 This standard may involve hazardous materials, operations, and equipment. 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: Historical
• Publication Date: 09-May-2003
• ICS: 29.040.10 - Insulating oils
• Technical Committee: D27 - Electrical Insulating Liquids and Gases
• Drafting Committee: D27.07 - Physical Test

Relations

• Replaces: ASTM D1698-97 - Standard Test Method for Sediments and Soluble Sludge in Service-Aged Insulating Oils
• Effective Date: 10-May-2003
• Replaced By: ASTM D1698-03(2008) - Standard Test Method for Sediments and Soluble Sludge in Service-Aged Insulating Oils (Withdrawn 2014)
• Effective Date: 01-May-2008

Standards Content (Sample)

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Contact ASTM International (www.astm.org) for the latest information
Designation: D 1698 – 03
Standard Test Method for
Sediments and Soluble Sludge in Service-Aged Insulating
1
Oils
This standard is issued under the fixed designation D 1698; 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 (e) indicates an editorial change since the last revision or reapproval.
1. Scope 4. Summary of Test Method
1.1 This test method covers the determination of sediment 4.1 A sample portion is centrifuged to separate sediment
and soluble sludge in service-aged insulating oils of petroleum from the oil. The upper, sediment-free portion is decanted and
origin. Also, provision is made for determining organic and retained for determination of soluble sludge. The sediment is
inorganic content of the sediment. The method is intended dislodged and filtered through a filtering crucible.After drying
primarily for oils of comparatively low viscosity; for example and weighing to obtain total sediment the crucible is ignited at
2
5.7 to 13.0 cSt (mm /s) at 40°C (104°F). Suitability for high 500°C and reweighed. Loss in weight is organic and the
viscosity oils have not been determined. remainder is inorganic content of sediment. Soluble sludge is
1.2 This standard may involve hazardous materials, opera- determined on the sediment-free portion by dilution with
tions, and equipment. This standard does not purport to n-pentane to precipitate n-pentane insolubles, and filtration
address all of the safety concerns, if any, associated with its through a filtering crucible or 0.45 µm filter membrane.
use. It is the responsibility of the user of this standard to
5. Significance and Use
establish appropriate safety and health practices and deter-
mine the applicability of regulatory limitations prior to use. 5.1 Sediment in insulating oil may deposit on transformer
parts and interfere with heat transfer and may choke oil ducts;
2. Referenced Documents
thus hindering oil circulation and heat dissipation. Inorganic
2.1 ASTM Standards: sediment usually indicates contamination of some type and
2
D 923 Practices for Sampling Electrical Insulating Liquids organic sediment indicates either deterioration of the oil or
D 2440 Test Method for Oxidation Stability of Mineral contamination.
2
Insulating Oil 5.2 Soluble sludge indicates deterioration of the oil, pres-
ence of contaminants, or both. It serves as a warning that
3. Terminology
formation of sediment may be imminent.
3.1 Definitions of Terms Specific to This Standard:
5.3 The determination of sediment and soluble sludge in a
3.1.1 inorganic sediment—that portion of the total sediment used insulating oil assists in deciding whether the oil may
which remains after ignition at 500°C.
continue to be used in its existing condition or should be
3.1.2 organic sediment—that portion of the total sediment replaced, reclaimed, or reconditioned.
which is lost during ignition at 500°C.
6. Apparatus
3.1.3 sediment—any solid substance or substances that are
insoluble in the oil under test at ordinary room temperatures, 6.1 Centrifuge Tube, 30-mLcapacity, preferably with round
and that can be separated by centrifuging under certain or elliptical bottom to facilitate removal of sediment. Pear-
prescribed conditions. shaped tubes are not recommended.
3.1.4 soluble sludge—oil deterioration products or contami- 6.2 Centrifuge, capable of whirling two or more filled
nants, or both, which become insoluble upon dilution with centrifuge tubes at a speed which can be controlled to give a
n-pentane under prescribed conditions. relative centrifugal force (rcf) between 600 and 700 at the tips
of the tubes. The revolving head, trunnion rings, and trunnion
cups, including the rubber cushion, shall be soundly con-
1
This test method is under the jurisdiction of ASTM Committee D27 on
structedtowithstandthemaximumcentrifugalforcecapableof
Electrical Insulating Liquids and Gases and is the direct responsibility of Subcom-
mittee D27.07 on Physical Tests.
being delivered by the power source. The trunnion cups and
Current edition approved May 10, 2003. Published July 2003. Originally
cushions shall firmly support the tubes when the centrifuge is
approved in 1959. Last previous edition approved in 1997 as D 1698 – 97.
inmotion.Thecentrifugeshallbeenclosedbyametalshieldor
2
Annual Book of ASTM Standards, Vol 10.03.
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D 1698 – 03
case strong enough to eliminate danger if any breakage occurs. washes of 25-mL portions each are sufficient. A drop of the
Calculate the speed of the rotating head by means of the
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