Standard Test Method for Water and Sediment in Crude Oil by Centrifuge Method

This standard is issued under the fixed designation D 96; 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. This method has been approved by the sponsoring committees and accepted by the Cooperating Societies in accordance with established procedures. This test method has been adopted for use by government agencies to replace Method 3003 of Federal Test Method Standard No. 791b. Annex A1 is under revision and will be included in subsequent revisions to this standard. 1. Scope 1.1 This test method covers the centrifuge method for determining sediment and water in crude oil during field custody transfers. This test method may not always provide the most accurate results, but it is considered the most practical method for field determination of sediment and water. When a higher degree of accuracy is required, the laboratory procedure described in Test Methods D 4006, D 4377 or D 473 should be used. NOTE 1—Water by distillation and sediment by extraction are considered the most accurate methods of determining sediment and water in crude oils. As such, these methods should be employed to resolve differences in results from variations of this procedure or between this procedure and other methods, or in the case of a dispute between parties. 1.2 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. 2. Referenced Documents 2.1 ASTM Standards: D 235 Specification for Mineral Spirits (Petroleum Spirits) (Hydrocarbon Drycleaning Spirits)2 D 362 Specification for Industrial Grade Toluene2 D 473 Test Method for Sediment in Crude Oils and Fuel Oils by the Extraction Method3 D 846 Specification for Ten-Degree Xylene2 D 1209 Test Method for Color of Clear Liquids (Platinum- Cobalt Scale)2 D 3699 Specification for Kerosine4 D 4006 Test Method for Water in Crude Oil by Distillation4 D 4057 Practice for Manual Sampling of Petroleum and Petroleum Products4 D 4177 Practice for Automatic Sampling of Petroleum and Petroleum Products4 D 4377 Test Method for Water in Crude Oils by Potentiometric Karl Fischer Titration4 E 1 Specification for ASTM Thermometers5 E 542 Practice for Calibration of Volumetric Ware6 2.2 API Standards:7 Manual of Petroleum Measurement Standards Chapter 8, Sampling Petroleum and Petroleum Products Chapter 10, Sediment and Water 3. Summary of Test Method 3.1 Known volumes of crude oil and solvent (water saturated if required) are placed in a centrifuge tube and heated to 60°C 6 3°C (140°F 6 5°F). After centrifugation, the volume of the sediment-and-water layer at the bottom of the tube is read. NOTE 2—It has been observed that for some waxy crude oils, temperatures of 71°C (160°F) or higher may be required to melt the wax crystals completely so that they are not measured as sediment. If temperatures higher than 60°C (140°F) are necessary to eliminate this problem, they may be used with the consent of the parties involved. If water saturation of the solvent is required, it must be done at the same temperature. 4. Significance and Use 4.1 A determination of sediment and water content is required to determine accurately the net volumes of crude oil involved in sales, taxation, exchanges, inventories, and custody transfers. An excessive amount of sediment and water in crud.

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1 This test method is under the jurisdiction of Committee D-2 on Petroleum
Products and Lubricants and is the direct responsibility of Subcommittee
D02.02.OB on Sediment and Water (Joint ASTM-JP).
Current edition approved March 25, 1988. Published December 1988. Originally
published as D 96 – 63T. Last previous edition D 96 – 73 (1984).e1
2 Annual Book of ASTM Standards, Vol 06.04.
3 Annual Book of ASTM Standards, Vol 05.01.
4 Annual Book of ASTM Standards, Vol 05.02.
5 Annual Book of ASTM Standards, Vol 14.03.
6 Annual Book of ASTM Standards, Vol 14.02.
7 Available from American Petroleum Institute, 1220 L St., Northwest, Washington,
DC 20005.

An American National Standard
British Standard 4385
American Association State
Highway Transportation Standard
AASHTO No. T55

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Reprinted from the Annual Book of ASTM Standards. Copyright ASTM