ASTM D1796-22

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: D1796 − 11 (Reapproved 2016) D1796 − 22
Manual of Petroleum Measurement Standards (MPMS), Chapter 10.6
Standard Test Method for
Water and Sediment in Fuel Oils by the Centrifuge Method
(Laboratory Procedure)
This standard is issued under the fixed designation D1796; 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.
This standard has been approved for use by agencies of the U.S. Department of Defense.
1. Scope Scope*
1.1 This test method describes the laboratory determination of water and sediment in fuel oils in the range from 0 % to 30 %
volume by means of the centrifuge procedure.
NOTE 1—With some types of fuel oils such as residual fuel oils or distillate fuel oils containing residual components, it is difficult to obtain water or
sediment contents with this test method. When this situation is encountered, Test Method D95 (API MPMS Chapter 10.5) or Test Method D473 (API
MPMS Chapter 10.1) may be used.
NOTE 2—API MPMS Chapter 10.6 (Test Method D1796) along with API MPMS Chapter 10.3 (Test Method D4007) formerly superseded API Standard
2548.
1.2 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only.
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 safety, health, and healthenvironmental practices and determine the
applicability of regulatory limitations prior to use. For a specific precautionary statement, see 6.17.1.
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:
D95 Test Method for Water in Petroleum Products and Bituminous Materials by Distillation (API MPMS Chapter 10.5)
D473 Test Method for Sediment in Crude Oils and Fuel Oils by the Extraction Method (API MPMS Chapter 10.1)
D4007 Test Method for Water and Sediment in Crude Oil by the Centrifuge Method (Laboratory Procedure) (API MPMS
Chapter 10.3)
D4057 Practice for Manual Sampling of Petroleum and Petroleum Products (API MPMS Chapter 8.1)
D4175 Terminology Relating to Petroleum Products, Liquid Fuels, and Lubricants
This test method is under the jurisdiction of ASTM Committee D02 on Petroleum Products, Liquid Fuels, and Lubricants and the API Committee on Petroleum
Measurement and is the direct responsibility of Subcommittee D02.02 /COMQ the joint ASTM-API Committee on Hydrocarbon Measurement for Custody Transfer (Joint
ASTM-API). This test method has been approved by the sponsoring committees and accepted by the Cooperating Societies in accordance with established procedures.
Current edition approved June 1, 2016Oct. 1, 2022. Published July 2016December 2022. Originally approved in 1960. Last previous edition approved in 20112016 as
ɛ1
D1796 – 11 (2016). . DOI: 10.1520/D1796-11R16.10.1520/D1796-22.
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
© Jointly copyrighted by ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, USA and the American Petroleum Institute (API), 1220 L Street NW, Washington DC 20005, USA
D1796 − 22
D4177 Practice for Automatic Sampling of Petroleum and Petroleum Products (API MPMS Chapter 8.2)
D5854 Practice for Mixing and Handling of Liquid Samples of Petroleum and Petroleum Products (API MPMS Chapter 8.3)
D6304 Test Method for Determination of Water in Petroleum Products, Lubricating Oils, and Additives by Coulometric Karl
Fischer Titration
E542 Practice for Gravimetric Calibration of Laboratory Volumetric Instruments
2.2 API Standards:
MPMS Chapter 1 Terms and Definitions Database
MPMS Chapter 8.1 Practice for Manual Sampling of Petroleum and Petroleum Products (ASTM Practice D4057)
MPMS Chapter 8.2 Practice for Automatic Sampling of Petroleum and Petroleum Products (ASTM Practice D4177)
MPMS Chapter 8.3 Practice for Mixing and Handling of Liquid Samples of Petroleum and Petroleum Products (ASTM Practice
D5854)
MPMS Chapter 10.1 Test Method for Sediment in Crude Oils by the Extraction Method (ASTM Test Method D473)
MPMS Chapter 10.3 Test Method for Water and Sediment in Crude Oil by the Centrifuge Method (Laboratory Procedure)
(ASTM Test Method D4007)
MPMS Chapter 10.5 Test Method for Water in Petroleum Products and Bituminous Materials by Distillation (ASTM Test
Method D95)
2.3 IP Standard:
Methods Book, Appendix B Specification for Methylbenzenes (Toluenes)
2.4 ISO Standard:
ISO 5272:1979 Toluene for Industrial Use—Specifications
3. Terminology
3.1 Definitions:
3.1.1 For definitions of terms used in this test method, refer to Terminology D4175 and the API MPMS Chapter 1 Terms and
Definitions Database.
4. Summary of Test Method
4.1 Equal volumes of fuel oil and water-saturated toluene are placed in each of two cone-shaped centrifuge tubes. After
centrifugation, the volume of the higher density water and sediment layer at the bottom of the tube is read.
5. Significance and Use
5.1 The water and sediment content of fuel oil is significant because it can cause corrosion of equipment and problems in
processing. A determination of water and sediment content is required to measure accurately net volumes of actual fuel oil in sales,
taxation, exchanges, and custody transfers.
5.2 This test method may not be suitable for products that contain alcohols that are soluble in water. In cases where the impact
on the results may be significant, the user is advised to consider using another test method, such as Test Method D6304.
6. Apparatus
6.1 Centrifuge:
6.1.1 Use a centrifuge capable of spinning two or more filled cone-shaped 203 mm (8 in.) centrifuge tubes at a speed that can be
controlled to give a relative centrifugal force (rcf) of between 500 and 800 at the tip of the tubes (see 5.1.66.1.6).
6.1.2 The revolving head, trunnion rings, and trunnion cups, including the cushions, shall be soundly constructed to withstand the
maximum centrifugal force capable of being delivered by the power source. The trunnion cups and cushions shall firmly support
the tubes when the centrifuge is in motion. The centrifuge shall be enclosed by a metal shield or case strong enough to eliminate
danger if any breakage occurs.
Published as Manual of Petroleum Measurement Standards. Available from the American Petroleum Institute, 1220 L St., N.W., Washington, DC 20005.
Available from Energy Institute, 61 New Cavendish St., London, WIG 7AR, U.K.
Available from American National Standards Institute (ANSI), 25 W. 43rd St., 4th Floor, New York, NY 10036, http://www.ansi.org.
D1796 − 22
6.1.3 The centrifuge shall be heated and controlled thermostatically to avoid unsafe conditions. It shall be capable of maintaining
the sample temperature during the entire process at 60 °C 6 1 °C (140 °F 6 1.8 °F). The thermostatic control shall be capable of
maintaining the temperature within these limits and operate safely if there is a flammable atmosphere.
6.1.4 Electric powered and heated centrifuges must meet all safety requirements for use in hazardous areas.
NOTE 3—Some heated centrifuges maintain the bowl at a pressure slightly below atmospheric pressure and reduce the hazards associated with vapors and
gasses, produced by samples and solvents used in the tests, by discharging any vapors to a non-hazardous area.
6.1.5 Calculate the speed of the rotating head in revolutions per minute (r/min) as follows:
r/min 5 1335 =rcf/d (1)
where:
rcf = relative centrifugal force, and
d = diameter of swing measured between tips of opposite tubes when in rotating position, mm,
or
r/min 5 265 =rcf/d (2)
where:
rcf = relative centrifugal force, and
d = diameter of swing measured between tips of opposite tubes when in rotating position, in.
6.1.6 Calculate the relative centrifugal force from a measured speed (r/min) as follows:
r/min
rcf 5 d (3)
S D
where:
d = diameter of swing measured between tips of opposite tubes when in rotating position, mm, or
r/min
rcf 5 d (4)
S D
where:
d = diameter of swing measured between tips of opposite tubes when in rotating position, in.
6.2 Centrifuge Tubes:
6.2.1 Each centrifuge tube shall be a cone-shaped tube, conforming to the dimensions given in Fig. 1, and made of thoroughly
annealed glass. The graduations, numbered as shown in Fig. 1, shall be clear and distinct, and the mouth shall be constricted in
shape for closure with a cork or solvent-resistant rubber stopper. Scale error tolerances and the smallest graduations between
various calibration marks are given in Table 1 and apply to calibrations made with air-free water at 20 °C (68 °F), when reading
the bottom of the shaded meniscus.
6.2.2 Volumetrically verify or gravimetrically certify the accuracy of the graduation marks, in accordance with Practice E542
using equipment traceable through the National Institute for Standards and Technology (NIST) or other national standards.
Include the verification or certification for each mark through the 0.5 mL mark; of the 1 mL, 1.5 mL, and 2 mL marks; and of the
50 mL and 100 mL marks. Do not use the tube if the scale error exceeds the applicable tolerance in Table 1.
Available from National Institute of Standards and Technology (NIST), 100 Bureau Dr., Stop 3460, Gaithersburg, MD 20899-3460.
D1796 − 22
FIG. 1 Eight-Inch (203 mm) Centrifuge Tube
TABLE 1 Centrifuge Tube Calibration Tolerances for
203-mm (8-in.) Tube
Range, mL Subdivision, mL Volume Tolerance, mL
0 to 0.1 0.05 ±0.02
Above 0.1 to 0.3 0.05 ±0.03
Above 0.3 to 0.5 0.05 ±0.05
Above 0.5 to 1.0 0.10 ±0.05
Above 1.0 to 2.0 0.10 ±0.10
Above 2.0 to 3.0 0.20 ±0.10
Above 3.0 to 5.0 0.50 ±0.20
Above 5.0 to 10 1.00 ±0.50
Above 10 to 25 5.00 ±1.00
Above 25 to 100 25.00 ±1.00
6.3 Bath—The bath shall be either a solid metal block bath or a liquid bath of sufficient depth for immersing the centrifuge tube
in the vertical position to the 100 mL mark. Provide the means for maintaining the temperature at 60 °C 6 1 °C (140 °F 6 1.8 °F).
See Note 4.
NOTE 4—It has been observed for some fuel oils that temperatures higher than 60 °C (140 °F) may be required to obtain correct sediment and water
content. If temperatures higher than 60 °C are necessary, they may be used only with the consent of the parties involved. Water saturation of toluene may
also be carried out at this higher testing temperature. (See Annex A1.)
7. Reagents
7.1 Toluene, conforming to the IP Specification for Methylbenzenes (Toluenes) or to ISO 5272. (Warning—Flammable. Keep
away from heat, sparks, and open flame. Vapor harmful. Toluene is toxic. Particular care must be taken to avoid breathing the vapor
and to protect the eyes. Keep container closed. Use with adequate ventilation. Avoid prolonged or repeated contact with the skin.)
7.1.1 Typical characteristics for this reagent are:
D1796 − 22
Molecular weight C H CH 92.14
6 5 3
Color (APHA) 10
A
Boiling range (initial to dry point) 2.0 °C (3.6 °F)
Residue after evaporation 0.001 %
Substances darkened by H SO passes ACS test
2 4
Sulfur compounds (as S) 0.003 %
A
Recorded boiling point 110.6 °C.
NOTE 5—Some oils may require other solvents or solvent-demulsifier combinations. Those agreed upon between the purchaser and the seller may be used.
7.1.2 The solvent shall be water-saturated at 60 °C 6 1 °C (140 °F 6 1.8 °F) but shall be free of suspended water. See Annex A1
for the solvent-water saturation procedure.
7.2 Demulsifiers:
7.2.1 Where necessary, use a demulsifier to promote the separation of water from the sample, to prevent water from clinging to
the walls of the centrifuge tube, and to enhance the distinctness of the water-oil interface.
7.2.2 When using a demulsifier, it should be mixed according to the manufacturer’s recommendations and should never be added
to the volume of sediment and water determined. Always use the demulsifier in the form of a demulsifier-solvent stock solution
or be premixed with the solvent to be used in the test.
8. Sampling
8.1 Sampling is defined as all steps required to obtain an aliquot of the contents of any pipe, tank, or other system and to
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