ASTM D1796-11(2016)

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.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: D1796 − 11 (Reapproved 2016)
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 2. Referenced Documents
1.1 This test method describes the laboratory determination 2.1 ASTM Standards:
of water and sediment in fuel oils in the range from 0 % to D95 Test Method for Water in Petroleum Products and
30 % volume by means of the centrifuge procedure. Bituminous Materials by Distillation (API MPMS Chapter
NOTE 1—With some types of fuel oils such as residual fuel oils or
10.5)
distillate fuel oils containing residual components, it is difficult to obtain
D473 Test Method for Sediment in Crude Oils and Fuel Oils
water or sediment contents with this test method. When this situation is
by the Extraction Method (API MPMS Chapter 10.1)
encountered,Test Method D95 (API MPMS Chapter 10.5) orTest Method
D4007 Test Method forWater and Sediment in Crude Oil by
D473 (API MPMS Chapter 10.1) may be used.
NOTE 2—API MPMS Chapter 10.6 (Test Method D1796) along with the Centrifuge Method (Laboratory Procedure) (API
API MPMS Chapter 10.3 (Test Method D4007) formerly superseded API
MPMS Chapter 10.3)
Standard 2548.
D4057 Practice for Manual Sampling of Petroleum and
1.2 The values stated in SI units are to be regarded as the Petroleum Products (API MPMS Chapter 8.1)
standard. The values given in parentheses are for information
D4177 Practice for Automatic Sampling of Petroleum and
only. Petroleum Products (API MPMS Chapter 8.2)
D5854 Practice for Mixing and Handling of Liquid Samples
1.3 This standard does not purport to address all of the
of Petroleum and Petroleum Products (API MPMS Chap-
safety concerns, if any, associated with its use. It is the
ter 8.3)
responsibility of the user of this standard to establish appro-
D6304 Test Method for Determination of Water in Petro-
priate safety and health practices and determine the applica-
leum Products, Lubricating Oils, and Additives by Cou-
bility of regulatory limitations prior to use. For a specific
lometric Karl Fischer Titration
precautionary statement, see 6.1.
E542 Practice for Calibration of Laboratory Volumetric
1.4 This international standard was developed in accor-
Apparatus
dance with internationally recognized principles on standard-
2.2 API Standards:
ization established in the Decision on Principles for the
MPMS Chapter 8.1 Practice for Manual Sampling of Petro-
Development of International Standards, Guides and Recom-
leum and Petroleum Products (ASTM Practice D4057)
mendations issued by the World Trade Organization Technical
MPMS Chapter 8.2 Practice for Automatic Sampling of
Barriers to Trade (TBT) Committee.
Petroleum and Petroleum Products (ASTM Practice
D4177)
This test method is under the jurisdiction of ASTM Committee D02 on
MPMS Chapter 8.3 Practice for Mixing and Handling of
Petroleum Products, Liquid Fuels, and Lubricants and the API Committee on
Liquid Samples of Petroleum and Petroleum Products
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 For referenced ASTM standards, visit the ASTM website, www.astm.org, or
sponsoring committees and accepted by the Cooperating Societies in accordance contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
with established procedures. Standards volume information, refer to the standard’s Document Summary page on
CurrenteditionapprovedJune1,2016.PublishedJuly2016.Originallyapproved the ASTM website.
ɛ1 3
in 1960. Last previous edition approved in 2011 as D1796 – 11 . DOI: 10.1520/ Published as Manual of Petroleum Measurement Standards.Available from the
D1796-11R16. American Petroleum Institute, 1220 L St., N.W., Washington, DC 20005.
© 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 − 11 (2016)
(ASTM Practice D5854) 5.1.4 Electric powered and heated centrifuges must meet all
MPMS Chapter 10.1 Test Method for Sediment in Crude safety requirements for use in hazardous areas.
Oils by the Extraction Method (ASTM Test Method
NOTE 3—Some heated centrifuges maintain the bowl at a pressure
D473)
slightly below atmospheric pressure and reduce the hazards associated
MPMS Chapter 10.3 Test Method forWater and Sediment in
with vapors and gasses, produced by samples and solvents used in the
Crude Oil by the Centrifuge Method (Laboratory Proce- tests, by discharging any vapors to a non-hazardous area.
dure) (ASTM Test Method D4007)
5.1.5 Calculate the speed of the rotating head in revolutions
MPMS Chapter 10.5 Test Method for Water in Petroleum
per minute (r/min) as follows:
Products and Bituminous Materials by Distillation
(ASTM Test Method D95) r/min 5 1335 =rcf/d (1)
2.3 IP Standard:
where:
Methods Book, Appendix B Specification for Methylben-
rcf = relative centrifugal force, and
zenes (Toluenes)
d = diameter of swing measured between tips of opposite
2.4 ISO Standard:
tubes when in rotating position, mm,
ISO 5272:1979 Toluene for Industrial Use—Specifications
or
3. Summary of Test Method
r/min 5 265 =rcf/d (2)
3.1 Equal volumes of fuel oil and water-saturated toluene
where:
are placed in each of two cone-shaped centrifuge tubes. After
centrifugation, the volume of the higher density water and rcf = relative centrifugal force, and
sediment layer at the bottom of the tube is read. d = diameter of swing measured between tips of opposite
tubes when in rotating position, in.
4. Significance and Use
5.1.6 Calculate the relative centrifugal force from a mea-
4.1 The water and sediment content of fuel oil is significant
sured speed (r/min) as follows:
because it can cause corrosion of equipment and problems in
r/min
processing. A determination of water and sediment content is
rcf 5 d (3)
S D
required to measure accurately net volumes of actual fuel oil in
sales, taxation, exchanges, and custody transfers.
where:
4.2 This test method may not be suitable for products that d = diameter of swing measured between tips of opposite
tubes when in rotating position, mm, or
contain alcohols that are soluble in water. In cases where the
impact on the results may be significant, the user is advised to
r/min
consider using another test method, such as Test Method
rcf 5 d (4)
S D
D6304.
where:
5. Apparatus
d = diameter of swing measured between tips of opposite
5.1 Centrifuge: tubes when in rotating position, in.
5.1.1 Use a centrifuge capable of spinning two or more
5.2 Centrifuge Tubes:
filled cone-shaped 203 mm (8 in.) centrifuge tubes at a speed
5.2.1 Each centrifuge tube shall be a cone-shaped tube,
that can be controlled to give a relative centrifugal force (rcf)
conforming to the dimensions given in Fig. 1, and made of
of between 500 and 800 at the tip of the tubes (see 5.1.6).
thoroughly annealed glass. The graduations, numbered as
5.1.2 Therevolvinghead,trunnionrings,andtrunnioncups,
shown in Fig. 1, shall be clear and distinct, and the mouth shall
including the cushions, shall be soundly constructed to with-
be constricted in shape for closure with a cork or solvent-
stand the maximum centrifugal force capable of being deliv-
resistant rubber stopper. Scale error tolerances and the smallest
eredbythepowersource.Thetrunnioncupsandcushionsshall
graduations between various calibration marks are given in
firmly support the tubes when the centrifuge is in motion. The
Table 1 and apply to calibrations made with air-free water at
centrifuge shall be enclosed by a metal shield or case strong
20 °C (68 °F), when reading the bottom of the shaded menis-
enough to eliminate danger if any breakage occurs.
cus.
5.1.3 The centrifuge shall be heated and controlled thermo-
5.2.2 Volumetrically verify or gravimetrically certify the
statically to avoid unsafe conditions. It shall be capable of
accuracy of the graduation marks, in accordance with Practice
maintainingthesampletemperatureduringtheentireprocessat
E542 using equipment traceable through the National Institute
60 °C 61 °C(140 °F 61.8 °F).Thethermostaticcontrolshall
for Standards and Technology (NIST) or other national
be capable of maintaining the temperature within these limits
standards. Include the verification or certification for each
and operate safely if there is a flammable atmosphere.
mark through the 0.5 mLmark; of the 1 mL, 1.5 mL, and 2 mL
Available from Energy Institute, 61 New Cavendish St., London, WIG 7AR,
U.K.
5 6
Available fromAmerican National Standards Institute (ANSI), 25 W. 43rd St., Available from National Institute of Standards and Technology (NIST), 100
4th Floor, New York, NY 10036, http://www.ansi.org. Bureau Dr., Stop 3460, Gaithersburg, MD 20899-3460.
D1796 − 11 (2016)
closed. Use with adequate ventilation. Avoid prolonged or
repeated contact with the skin.)
6.1.1 Typical characteristics for this reagent are:
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.
6.1.2 The solvent shall be water-saturated at 60 °C 61°C
(140 °F 6 1.8 °F) but shall be free of suspended water. See
Annex A1 for the solvent-water saturation procedure.
6.2 Demulsifiers:
6.2.1 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.
6.2.2 When using a demulsifier, it should be mixed accord-
ing to the manufacturer’s recommendations and should never
be added to the volume of sediment and water determined.
FIG. 1 Eight-Inch (203 mm) Centrifuge Tube
Alwaysusethedemulsifierintheformofademulsifier-solvent
stocksolutionorbepremixedwiththesolventtobeusedinthe
TABLE 1 Centrifuge Tube Calibration Tolerances for
test.
203-mm (8-in.) Tube
Range, mL Subdivision, mL Volume Tolerance, mL
7. Sampling
0 to 0.1 0.05 ±0.02
Above 0.1 to 0.3 0.05 ±0.03
7.1 Sampling is defined as all steps required to obtain an
Above 0.3 to 0.5 0.05 ±0.05
aliquot of the contents of any pipe, tank, or other system and to
Above 0.5 to 1.0 0.10 ±0.05
Above 1.0 to 2.0 0.10 ±0.10 place them into the laboratory test container.
Above 2.0 to 3.0 0.20 ±0.10
7.2 Only representative samples obtained as specified in
Above 3.0 to 5.0 0.50 ±0.20
Above 5.0 to 10 1.00 ±0.50
Practice D4057 (API MPMS Chapter 8.1) and Practice D4177
Above 10 to 25 5.00 ±1.00
(API MPMS Chapter 8.2) shall be used for this test method.
Above 25 to 100 25.00 ±1.00
7.3 Practice D5854 (API MPMS Chapter 8.3) contains
additional information on sampling and homogenization effi-
ciency of an untested mixer. Do not use this test method
marks; and of the 50 mL and 100 mL marks. Do not use the
without strict adherence to Practice D5854 (API MPMS
tube if the scale error exceeds the applicable tolerance in Table
Chapter 8.3).
1.
5.3 Bath—The bath shall be either a solid metal block bath
8. Procedure
or a liquid bath of sufficient depth for immersing the centrifuge
8.1 Filleachoftwocentrifugetubes(5.2)tothe50 mLmark
tube in the vertical position to the 100 mL mark. Provide the
withthewell-mixedsampledirectlyfromthesamplecontainer.
meansformaintainingthetemperatureat60 °C 61 °C(140 °F
Usingapipette,add50 mLofthewater-saturatedsolvent(6.1).
6 1.8 °F). See Note 4.
Read the top of the meniscus at both the 50 mL and 100 mL
NOTE 4—It has been observed for some fuel oils that temperatures
marks. Stopper the tubes tightly and shake vigorously until the
higherthan60 °C(140 °F)mayberequiredtoobtaincorrectsedimentand
water content. If temperatures higher than 60 °C are necessary, they may
contents are thoroughly mixed. Loosen the stoppers on the
be used only with the consent of the parties involved. Water saturation of
tubes and immerse the tubes to the 100 mLmark for 10 min in
toluene may also be carried out at this higher testing temperature. (See
the bath maintained at 60 °C 6 1 °C (140 °F 6 1.8 °F).
Annex A1.)
8.2 Tighten the stoppers and again invert the tubes to ensure
6. Reagents
that the oil and solvent are uniformly mixed and shake
6.1 Toluene, conforming to the IP Specification for Methyl- cautiously. (Warning—In general, the vapor pressures of
benzenes (Toluenes) or to ISO 5272. (Warning—Flammable. hydrocarbons at 60 °C (140 °F) are approximately double
Keep away from heat, sparks, and open flame. Vapor harmful. those at 40 °C (104 °F). Consequently, invert the tubes at a
Toluene is toxic. Particular care must be taken to avoid position below eye level so that contact will be avoided if the
breathing the vapor and to protect the eyes. Keep container stopper is blown out.)
D1796 − 11 (2016)
8.3 Place the tubes in the trunnion cups on opposite sides of 9. Calculation
the centrifuge to establish a balanced condition and ensure that
9.1 Record the final volume of water and sediment in each
the tubes and stoppers do not touch adjacent or opposite tubes
tube. If the difference between the two readings is greater than
when in the extended position. Spin for 10 min at a rate,
one subdivision on the centrifuge tube (see Table 1)or
calculated from the equation given in 5.1.6, sufficient to
0.025 mL for readings of 0.10 mL and below, the readings are
produce a relative centrifugal force (rcf) of between 500 and
inadmissible and the determination shall be repeated.
800 at the tip of the whirling tubes (see Table 2 for the
9.2 Calculate the water and sediment of the sample as
relationship between diameter of swing, relative centrifugal
follows:
force,andrevolutionsperminute).Maintainthetemperatureof
V 5 V 1V (5)
the sample during the entire centrifuging procedure at 60 °C 6
1 2
1 °C (140 °F 6 1.8 °F). (See Note 4.)
where:
8.4 Immediat
...