ASTM D4006-11(2012)e1

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
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´1
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 U.S. Department of Defense.
ε NOTE—API information was editorially corrected in July 2013.
1. Scope* D4177Practice for Automatic Sampling of Petroleum and
Petroleum Products (API MPMS Chapter 8.2)
1.1 This test method covers the determination of water in
D4928Test Method forWater in Crude Oils by Coulometric
crude oil by distillation.
Karl Fischer Titration (API MPMS Chapter 10.9)
1.2 The values stated in SI units are to be regarded as
E123SpecificationforApparatusforDeterminationofWater
standard. No other units of measurement are included in this
by Distillation
standard.
2.2 API Standards:
1.3 This standard does not purport to address all of the
MPMS Chapter 8.1Manual Sampling of Petroleum and
safety concerns, if any, associated with its use. It is the
Petroleum Products (ASTM Practice D4057)
responsibility of the user of this standard to establish appro-
MPMS Chapter 8.2Automatic Sampling of Petroleum and
priate safety and health practices and determine the applica-
Petroleum Products (ASTM Practice D4177)
bility of regulatory limitations prior to use. For specific
MPMS Chapter 10.1Test Method for Sediment in Crude
warning statements, see 6.1 and A1.1.
Oils and Fuel Oils by the Extraction Method (ASTMTest
Method D473)
2. Referenced Documents
MPMS Chapter 10.4Determination of Water and/or Sedi-
2.1 ASTM Standards:
ment in Crude Oil by the Centrifuge Method (Field
D95Test Method for Water in Petroleum Products and Procedure)
BituminousMaterialsbyDistillation(API MPMSChapter
MPMS Chapter 10.5Test Method for Water in Petroleum
10.5) Products and Bituminous Materials by Distillation
D473TestMethodforSedimentinCrudeOilsandFuelOils
(ASTM Test Method D95)
by the Extraction Method (API MPMS Chapter 10.1) MPMSChapter10.6TestMethodforWaterandSedimentin
D665Test Method for Rust-Preventing Characteristics of
Fuel Oils by the Centrifuge Method (Laboratory Proce-
Inhibited Mineral Oil in the Presence of Water dure) (ASTM Test Method D1796)
D1796Test Method for Water and Sediment in Fuel Oils by
MPMSChapter10.9TestMethodforWaterinCrudeOilsby
the Centrifuge Method (Laboratory Procedure) (API Coulometric Karl Fischer Titration (ASTM Test Method
MPMS Chapter 10.6)
D4928)
D4057Practice for Manual Sampling of Petroleum and
Petroleum Products (API MPMS Chapter 8.1)
3. Summary of Test Method
3.1 The sample is heated under reflux conditions with a
waterimmisciblesolventwhichco-distillswiththewaterinthe
This test method is under the jurisdiction of ASTM Committee D02 on
sample. Condensed solvent and water are continuously sepa-
Petroleum Products, Liquid Fuels, and Lubricants and the API Committee on
ratedinatrap—thewatersettlesinthegraduatedsectionofthe
Petroleum Measurement and is the direct responsibility of Subcommittee D02.02
/COMQ on Hydrocarbon Measurement for Custody Transfer (Joint ASTM-API). trap, and the solvent returns to the distillation flask.
Current edition approved Nov. 1, 2012. Published December 2012. Originally
approved in 1981. Last previous edition approved in 2011 as D4006–11. DOI:
4. Significance and Use
10.1520/D4006-11R12E01.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
4.1 A knowledge of the water content of crude oil is
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
important in the refining, purchase, sale, or transfer of crude
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website. oils.
*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
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D4006 − 11 (2012)
5.1.3 The apparatus used in this test will be accepted when
satisfactory results are obtained by the calibration technique
described in Section 8.
6. Solvent
6.1 Xylene—reagent grade (Warning—Extremely flam-
mable.Vapor harmful. See AnnexA1.)Asolvent blank will be
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
FIG. 1 Distillation Apparatus
place the sample into the laboratory test container.
7.1.1 Laboratory Sample—Only representative samples ob-
tainedasspecifiedinPracticeD4057(API MPMSChapter8.1)
4.2 This test method may not be suitable for crude oils that
contain alcohols that are soluble in water. In cases where the andPracticeD4177(API MPMSChapter8.2)shallbeusedfor
this test method.
impact on the results may be significant, the user is advised to
consider using another test method, such as Test Method
7.1.2 Preparation of Test Samples—The following sample
D4928 (API MPMS Chapter 10.9). handling procedure shall apply in addition to those covered in
7.1.1.
5. Apparatus
7.1.2.1 Thesamplesizeshallbeselectedasindicatedbelow
5.1 The preferred apparatus, shown in Fig. 1, consists of a based on the expected water content of the sample:
glassdistillationflask,acondenser,agraduatedglasstrap, and
Expected Water Content, Approximate Sample Size,
weight or volume % gormL
a heater. Other types of distillation apparatus are specified in
50.1–100.0 5
Specification E123.Any of these apparatus will be acceptable
25.1– 50.0 10
for this test method provided it can be demonstrated that they
10.1– 25.0 20
5.1– 10.0 50
operate within the precision established with the preferred
1.1– 5.0 100
apparatus.
0.5– 1.0 200
5.1.1 Distillation Flask—A 1000-mL round-bottom, glass,
less than 0.5 200
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
graduation. Carefully pour the contents of the cylinder into the
distillation flask and rinse the cylinder five times with portions
AvailableonspecialorderfromScientificGlassApparatusCo.,Bloomfield,NJ
07003. of xylene equivalent to one-fifth of the capacity of the
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D4006 − 11 (2012)
graduated cylinder and add the rinsings to the flask. Drain the anindicatingdesiccantintotheendofthecondensertoprevent
cylinder thoroughly to ensure complete sample transfer. condensation of atmospheric moisture inside the condenser.
7.1.2.4 To determine water on a mass basis, weigh a test
Circulate water, between 20 and 25°C, through the condenser
portion of sample in accordance with 7.1.2.1, pouring the
jacket.
sample directly into the distillation flask. If a transfer vessel
9.4 Apply heat to the flask. The type of crude oil being
(beaker or cylinder) must be used, rinse it with at least five
evaluated can significantly alter the boiling characteristics of
portions of xylene and add the rinsings to the flask.
the crude-solvent mixture. Heat should be applied slowly
8. Calibration 1
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
8.1.1–8.1.3.Additionally,calibrateboththetrapandtheentire quartersofthedistanceupthecondenserinnertube(Point Ain
assembly periodically, at a frequency not to exceed yearly. Fig. 1).) To facilitate condenser wash-down, the condensate
8.1.1 Verify the accuracy of the graduation marks on the
should be held as close as possible to the condenser outlet.
trap by adding 0.05-mLincrements of distilled water, at 20°C,
After the initial heating, adjust the rate of boiling so that the
from a 5-mLmicroburet or a precision micro-pipet readable to
condensate proceeds no more than three quarters of the
the nearest 0.01 mL. If there is a deviation of more than
distance up the condenser inner tube. Distillate should dis-
0.050mL between the water added and water observed, reject
chargeintothetrapattherateofapproximately2to5dropsper
the trap or recalibrate.
second. Continue distillation until no water is visible in any
8.1.2 Also calibrate the entire apparatus. Put 400 mLof dry
part of the apparatus, except in the trap, and the volume of
(0.02% water maximum) xylene in the apparatus and test in
water in the trap remains constant for at least 5 min. If there is
accordance with Section 9. When complete, discard the con-
a persistent accumulation of water droplets in the condenser
tentsofthetrapandadd1.00 60.01mLofdistilledwaterfrom
inner tube, flush with xylene. (A jet spray washing tube, see
the buret or micro-pipet, at 20°C, directly to the distillation
Fig. 2, or equivalent device is recommended.) The addition of
flask and test in accordance with Section 9. Repeat 8.1.2 and
anoil-solubleemulsionbreakerataconcentrationof1000ppm
add 4.50 6 0.01 mLdirectly to the flask. The assembly of the
to the xylene wash helps dislodge the clinging water drops.
apparatus is satisfactory only if trap readings are within the
Afterflushing,redistillforatleast5min(theheatmustbeshut
tolerances specified here:
off at least 15 min prior to wash-down to prevent bumping).
Limits Capacity Volume of Water Permissible for
After wash-down, apply heat slowly to prevent bumping.
of Trap at 20°C, Added at 20°C, Recovered Water
Repeatthisprocedureuntilnowaterisvisibleinthecondenser
mL mL at 20°C, mL
5.00 1.00 1.00± 0.025
andthevolumeofwaterinthetrapremainsconstantforatleast
5.00 4.50 4.50 ± 0.025
5 min. If this procedure does not dislodge the water, use the
8.1.3 A reading outside the limits suggests malfunctioning
TFE-fluorocarbon scraper, pick shown in Fig. 2, or equivalent
due to vapor leaks, too rapid boiling, inaccuracies in gradua-
device to cause the water to run into the trap.
tions of the trap, or ingress of extraneous moisture. These
9.5 When the carryover of water is complete, allow the trap
malfunctions must be eliminated before repeating 8.1.2.
and contents to cool to 20°C. Dislodge any drops of water
9. Procedure
adhering to the sides of the trap with the TFE-fluorocarbon
9.1 The precision of this test method can be affected by
scraper or pick and transfer them to the water layer. Read the
water droplets adhering to surfaces in the apparatus and
volume of the water in the trap. The trap is graduated in
therefore not settling into the water trap to be measured. To
0.05-mLincrements,butthevolumeisestimatedtothenearest
minimize the problem, all apparatus must be chemically
0.025 mL.
cleanedatleastdailytoremovesurfacefilmsanddebriswhich
hinder free drainage of water in the test apparatus. More
10. Calculation
frequent cleaning is recommended if the nature of the samples
10.1 Calculate the water in the sample as follows:
being run causes persistent contamination.
A 2 B
~ !
9.2 To determine water on a volume basis, proceed as
Volume% 5 3100 (1)
C
indicated in 7.1.2.3.Add sufficient xylene to the flask to make
the total xylene volume 400 mL.
~A 2 B!
Volume% 5 3100 (2)
9.2.1 To determine water on a mass basis, proceed as
M/D
~ !
indicated in 7.1.2.4.Add sufficient xylene to the flask to make
~A 2 B!
the total xylene volume 400 mL. Mass% 5 3100 (3)
M
9.2.2 A magnetic stirrer is the most effective device to
where:
reduce bumping. Glass beads or other boiling aids, although
less effective, have been found to be useful.
A = mL of water in trap,
B = mL of solvent blank,
9.3 AssembletheapparatusasshowninFig.1,makingsure
C = mL of test sample,
all connections are vapor and liquid-tight. It is recommended
M = g of test sample, and
that glass joints not be greased. Insert a drying tube containing
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D4006 − 11 (2012)
FIG. 2 Pick, Scraper, and Jet Spray Tube for Distillation Apparatus
material, would, in the long run, in the normal and correct
D = density of sample, g/mL.
operation of the test method, exceed the following value in
Volatile water-soluble material, if present, may be
only one case in twenty:
measured as water.
From 0.0 % to 0.1 % water, see Fig. 3.
11. Report Greater than 0.1 % water, repeatability is constant at 0.08.
11.1 Report the result as the water content to the nearest
0.025%, reporting water content of less than 0.025% as 0%,
12.1.2 Reproducibility—The difference between the two
and reference this Test Method D4006 (API MPMS Chapter
single and independent test results obtained by different
10.2) as the procedure used.
operators working in different laboratories on identical test
material, would, in the long run, in the normal and correct
12. Precision and Bias
operation of the test method, exceed the following value in
12.1 The precision of this test method, as obtained by
only one case in twenty:
statistical examinatio
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