ASTM D4006-11(2012)
(Test Method)Standard Test Method for Water in Crude Oil by Distillation
Standard Test Method for Water in Crude Oil by Distillation
SIGNIFICANCE AND USE
4.1 A knowledge of the water content of crude oil is important in the refining, purchase, sale, or transfer of crude oils.
4.2 This test method may not be suitable for crude oils 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 D4928 (API MPMS Chapter 10.9).
SCOPE
1.1 This test method covers the determination of water in crude oil by distillation.
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. For specific warning statements, see 6.1 and A1.1.
General Information
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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NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.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: D4006 − 11(Reapproved 2012)
Manual of Petroleum Measurement Standards (MPMS), Chapter 10.2
Standard Test Method for
Water in Crude Oil by Distillation
This standard is issued under the fixed designation D4006; 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.
This standard has been approved for use by agencies of the Department of Defense.
1. Scope* D4928Test Method forWater in Crude Oils by Coulometric
Karl Fischer Titration (API MPMS Chapter 10.9)
1.1 This test method covers the determination of water in
E123SpecificationforApparatusforDeterminationofWater
crude oil by distillation.
by Distillation
1.2 The values stated in SI units are to be regarded as
2.2 API Standards:
standard. No other units of measurement are included in this
MPMS Chapter 8.1Manual Sampling of Petroleum and
standard.
Petroleum Products (ASTM Practice D4057)
1.3 This standard does not purport to address all of the MPMS Chapter 8.2Automatic Sampling of Petroleum and
safety concerns, if any, associated with its use. It is the
Petroleum Products (ASTM Practice D4177)
responsibility of the user of this standard to establish appro- MPMS Chapter 10.1Test Method for Sediment in Crude
priate safety and health practices and determine the applica-
Oils and Fuel Oils by the Extraction Method (ASTMTest
bility of regulatory limitations prior to use. For specific Method D473)
warning statements, see 6.1 and A1.1.
MPMS Chapter 10.4Determination of Water and/or Sedi-
ment in Crude Oil by the Centrifuge Method (Field
2. Referenced Documents
Procedure)
2.1 ASTM Standards: MPMS Chapter 10.5Test Method for Water in Petroleum
D95Test Method for Water in Petroleum Products and Products and Bituminous Materials by Distillation
BituminousMaterialsbyDistillation(API MPMSChapter (ASTM Test Method D95)
10.5) MPMSChapter10.6TestMethodforWaterandSedimentin
D473TestMethodforSedimentinCrudeOilsandFuelOils Fuel Oils by the Centrifuge Method (Laboratory Proce-
dure) (ASTM Test Method D1796)
by the Extraction Method (API MPMS Chapter 10.1)
D665Test Method for Rust-Preventing Characteristics of MPMSChapter10.9TestMethodforWaterinCrudeOilsby
Coulometric Karl Fischer Titration (ASTM Test Method
Inhibited Mineral Oil in the Presence of Water
D1796Test Method for Water and Sediment in Fuel Oils by D4928)
the Centrifuge Method (Laboratory Procedure) (API
3. Summary of Test Method
MPMS Chapter 10.6)
3.1 The sample is heated under reflux conditions with a
D4057Practice for Manual Sampling of Petroleum and
waterimmisciblesolventwhichco-distillswiththewaterinthe
Petroleum Products (API MPMS Chapter 8.1)
sample. Condensed solvent and water are continuously sepa-
D4177Practice for Automatic Sampling of Petroleum and
ratedinatrap—thewatersettlesinthegraduatedsectionofthe
Petroleum Products (API MPMS Chapter 8.2)
trap, and the solvent returns to the distillation flask.
4. Significance and Use
This test method is under the jurisdiction of ASTM Committee D02 on
Petroleum Products and Lubricants and theAPI Committee on Petroleum Measure-
4.1 A knowledge of the water content of crude oil is
ment and is the direct responsibility of Subcommittee D02.02 /COMQ on Hydro-
important in the refining, purchase, sale, or transfer of crude
carbon Measurement for Custody Transfer (Joint ASTM-API).
This test method was issued as a joint ASTM-API-IP standard in 1981.
oils.
Current edition approved Nov. 1, 2012. Published December 2012. Originally
4.2 This test method may not be suitable for crude oils that
approved in 1981. Last previous edition approved in 2011 as D4006–11. DOI:
10.1520/D4006-11R12.
contain alcohols that are soluble in water. In cases where the
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
impact on the results may be significant, the user is advised to
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
consider using another test method, such as Test Method
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website. D4928 (API MPMS Chapter 10.9).
*A Summary of Changes section appears at the end of this standard
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D4006 − 11 (2012)
established by placing 400 mL of solvent in the distillation
apparatus and testing as outlined in Section 9. The blank will
be determined to the nearest 0.025 mLand used to correct the
volume of water in the trap as in Section 10.
6.2 Thexyleneusedinthisprocedureisgenerallyamixture
of ortho, meta, and para isomers and may contain some ethyl
benzene. The typical characteristics for this reagent are:
Color (APHA) not more than 10
Boiling range 137–144°C
Residue after evaporation 0.002 %
Sulfur compounds (as S) 0.003 %
Substances darkened by H SO Color pass test
2 4
Water (H O) 0.02 %
Heavy metals (as Pb) 0.1 ppm
Copper (Cu) 0.1 ppm
Iron (Fe) 0.1 ppm
Nickel (Ni) 0.1 ppm
Silver (Ag) 0.1 ppm
7. Sampling, Test Samples, and Test Units
7.1 Sampling is defined as all steps required to obtain an
aliquotofthecontentsofanypipe,tank,orothersystemandto
place the sample into the laboratory test container.
7.1.1 Laboratory Sample—Only representative samples ob-
tainedasspecifiedinPracticeD4057(API MPMSChapter8.1)
andPracticeD4177(API MPMSChapter8.2)shallbeusedfor
this test method.
7.1.2 Preparation of Test Samples—The following sample
FIG. 1 Distillation Apparatus
handling procedure shall apply in addition to those covered in
7.1.1.
7.1.2.1 Thesamplesizeshallbeselectedasindicatedbelow
5. Apparatus
based on the expected water content of the sample:
5.1 The preferred apparatus, shown in Fig. 1, consists of a
Expected Water Content, Approximate Sample Size,
glassdistillationflask,acondenser,agraduatedglasstrap, and
weight or volume % gormL
a heater. Other types of distillation apparatus are specified in
50.1–100.0 5
25.1– 50.0 10
Specification E123.Any of these apparatus will be acceptable
10.1– 25.0 20
for this test method provided it can be demonstrated that they
5.1– 10.0 50
operate within the precision established with the preferred
1.1– 5.0 100
0.5– 1.0 200
apparatus.
less than 0.5 200
5.1.1 Distillation Flask—A 1000-mL round-bottom, glass,
distillation flask fitted with a 24/40 female taper joint shall be 7.1.2.2 If there is any doubt about the uniformity of the
used. This flask receives a 5-mL calibrated, graduated water
mixedsample,determinationsshouldbemadeonatleastthree
trap with 0.05-mL graduations. The trap will be fitted with a test portions and the average result reported as the water
400-mm Liebig condenser.Adrying tube filled with desiccant
content.
(to prevent entrance of atmospheric moisture) is placed on top
7.1.2.3 To determine water on a volume basis, measure
of the condenser.
mobile liquids in a 5, 10, 20, 50, 100, or 200-mL calibrated,
5.1.2 Heater—Any suitable gas or electric heater that can
graduated cylinder (NBS Class A) depending on the sample
uniformly distribute heat to the entire lower half of the flask
size indicated in 7.1.2.1. Take care to pour the sample slowly
may be used.An electric heating mantle is preferred for safety
into the graduated cylinder to avoid entrapment of air and to
reasons.
adjust the level as closely as possible to the appropriate
5.1.3 The apparatus used in this test will be accepted when
graduation. Carefully pour the contents of the cylinder into the
satisfactory results are obtained by the calibration technique
distillation flask and rinse the cylinder five times with portions
described in Section 8.
of xylene equivalent to one-fifth of the capacity of the
graduated cylinder and add the rinsings to the flask. Drain the
6. Solvent
cylinder thoroughly to ensure complete sample transfer.
6.1 Xylene—reagent grade (Warning—Extremely flam-
7.1.2.4 To determine water on a mass basis, weigh a test
mable.Vapor harmful. See AnnexA1.)Asolvent blank will be
portion of sample in accordance with 7.1.2.1, pouring the
sample directly into the distillation flask. If a transfer vessel
(beaker or cylinder) must be used, rinse it with at least five
AvailableonspecialorderfromScientificGlassApparatusCo.,Bloomfield,NJ
07003. portions of xylene and add the rinsings to the flask.
D4006 − 11 (2012)
8. Calibration during the initial stages of the distillation (approximately ⁄2 to
1 h) to prevent bumping and possible loss of water from the
8.1 Calibrate both the trap and the entire assembly prior to
system. (Condensate shall not proceed higher than three
initial use and after any equipment changes as indicated in
quartersofthedistanceupthecondenserinnertube(Point Ain
8.1.1-8.1.3.Additionally, calibrate both the trap and the entire
Fig. 1).) To facilitate condenser wash-down, the condensate
assembly periodically, at a frequency not to exceed yearly.
should be held as close as possible to the condenser outlet.
8.1.1 Verify the accuracy of the graduation marks on the
After the initial heating, adjust the rate of boiling so that the
trap by adding 0.05-mLincrements of distilled water, at 20°C,
condensate proceeds no more than three quarters of the
from a 5-mLmicroburet or a precision micro-pipet readable to
distance up the condenser inner tube. Distillate should dis-
the nearest 0.01 mL. If there is a deviation of more than
chargeintothetrapattherateofapproximately2to5dropsper
0.050mL between the water added and water observed, reject
second. Continue distillation until no water is visible in any
the trap or recalibrate.
part of the apparatus, except in the trap, and the volume of
8.1.2 Also calibrate the entire apparatus. Put 400 mLof dry
water in the trap remains constant for at least 5 min. If there is
(0.02% water maximum) xylene in the apparatus and test in
a persistent accumulation of water droplets in the condenser
accordance with Section 9. When complete, discard the con-
inner tube, flush with xylene. (A jet spray washing tube, see
tentsofthetrapandadd1.00 60.01mLofdistilledwaterfrom
Fig. 2, or equivalent device is recommended.) The addition of
the buret or micro-pipet, at 20°C, directly to the distillation
anoil-solubleemulsionbreakerataconcentrationof1000ppm
flask and test in accordance with Section 9. Repeat 8.1.2 and
to the xylene wash helps dislodge the clinging water drops.
add 4.50 6 0.01 mLdirectly to the flask. The assembly of the
Afterflushing,redistillforatleast5min(theheatmustbeshut
apparatus is satisfactory only if trap readings are within the
off at least 15 min prior to wash-down to prevent bumping).
tolerances specified here:
After wash-down, apply heat slowly to prevent bumping.
Limits Capacity Volume of Water Permissible for
Repeatthisprocedureuntilnowaterisvisibleinthecondenser
of Trap at 20°C, Added at 20°C, Recovered Water
mL mL at 20°C, mL andthevolumeofwaterinthetrapremainsconstantforatleast
5.00 1.00 1.00± 0.025
5 min. If this procedure does not dislodge the water, use the
5.00 4.50 4.50 ± 0.025
TFE-fluorocarbon scraper, pick shown in Fig. 2, or equivalent
8.1.3 A reading outside the limits suggests malfunctioning
device to cause the water to run into the trap.
due to vapor leaks, too rapid boiling, inaccuracies in gradua-
9.5 When the carryover of water is complete, allow the trap
tions of the trap, or ingress of extraneous moisture. These
and contents to cool to 20°C. Dislodge any drops of water
malfunctions must be eliminated before repeating 8.1.2.
adhering to the sides of the trap with the TFE-fluorocarbon
9. Procedure scraper or pick and transfer them to the water layer. Read the
volume of the water in the trap. The trap is graduated in
9.1 The precision of this test method can be affected by
0.05-mLincrements,butthevolumeisestimatedtothenearest
water droplets adhering to surfaces in the apparatus and
0.025 mL.
therefore not settling into the water trap to be measured. To
minimize the problem, all apparatus must be chemically
10. Calculation
cleanedatleastdailytoremovesurfacefilmsanddebriswhich
hinder free drainage of water in the test apparatus. More
10.1 Calculate the water in the sample as follows:
frequent cleaning is recommended if the nature of the samples
A 2 B
~ !
being run causes persistent contamination.
Volume% 5 3100 (1)
C
9.2 To determine water on a volume basis, proceed as
~A 2 B!
indicated in 7.1.2.3.Add sufficient xylene to the flask to make Volume% 5 3100 (2)
M/D
~ !
the total xylene volume 400 mL.
A 2 B
~ !
9.2.1 To determine water on a mass basis, proceed as
Mass% 5 3100 (3)
M
indicated in 7.1.2.4.Add sufficient xylene to the flask to make
the total xylene volume 400 mL.
where:
9.2.2 A magnetic stirrer is the most effective device to
A = mL of water in trap,
reduce bumping. Glass beads or other boiling aids, although
B = mL of solvent blank,
less effective, have been found to be useful.
C = mL of test sample,
M = g of test sample, and
9.3 AssembletheapparatusasshowninFig.1,makingsure
D = density of sample, g/mL.
all connections are vapor and liquid-tight. It is recommended
Volatile water-soluble material, if present, may be
that glass joints not be greased. Insert a drying tube containing
measured as water.
anindicatingdesiccantintotheendofthecondensertoprevent
condensation of atmospheric moisture inside the condenser.
11. Report
Circulate water, between 20 and 25°C, through the condenser
jacket.
11.1 Report the result as the water content to the nearest
9.4 Apply heat to the flask. The type of crude oil being 0.025%, reporting water content of less than 0.025% as 0%,
evaluated can significantly alter the boiling characteristics of and reference this Test Method D4006 (API MPMS Chapter
the crude-solvent mixture. Heat should be applied slowly 10.2) as the procedure used.
D4006 − 11 (2012)
FIG. 2 Pick, Scraper, and Jet Spray Tube for Distillation Apparatus
12. Precision and Bias
12.1.2 Reproducibility—The difference between the two
12.1 The precision of this test method, as obtained by
single and independent test results obtained by different
statistical examination of interlaboratory test results in the
operators working in different laboratories on identical test
range from 0.01 to 1.0%, is described in 12.1.1 and 12.1.2.
12.1.1 Repeatability—The difference between successive material, would, in the long run, in the normal and correct
test results, obtained by the same operator with the same operation of the test method, exceed the following value in
apparatus under constant operating conditions on identical test only one ca
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