ASTM D95

1

Manual of Petroleum Measurement Standards(MPMS),Chapter10.5 Standard Test Method for

Water in Petroleum Products and Bituminous Materials by Distillation1

This standard is issued under thefixed designation D95;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.

ε1NOTE—IP information was removed editorially in September2013.

1.Scope*

1.1This test method covers the determination of water in the range from0to25%volume in petroleum products,tars, and other bituminous materials by the distillation method.

N OTE1—V olatile water-soluble material,if present,may be measured as water.

1.2The specific products considered during the develop-ment of this test method are listed in Table 1.For bituminous emulsions refer to Test Method D244.For crude oils,refer to Test Method D4006(API MPMS Chapter10.2).

N OTE2—With some types of oil,satisfactory results may be obtained from Test Method D1796(API MPMS Chapter10.6).

1.3The values stated in SI units are to be regarded as the standard.The values in parentheses are for information only.

1.4This 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 appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.For specific hazard statements,see Section6.

2.Referenced Documents

2.1ASTM Standards:2

D235Specification for Mineral Spirits(Petroleum Spirits) (Hydrocarbon Dry Cleaning Solvent)D244Test Methods and Practices for Emulsified Asphalts D1796Test Method for Water and Sediment in Fuel Oils by the Centrifuge Method(Laboratory Procedure)(API MPMS Chapter10.6)

D4006Test Method for Water in Crude Oil by Distillation (API MPMS Chapter10.2)

D4057Practice for Manual Sampling of Petroleum and Petroleum Products(API MPMS Chapter8.1)

D4177Practice for Automatic Sampling of Petroleum and Petroleum Products(API MPMS Chapter8.2)

D5854Practice for Mixing and Handling of Liquid Samples of Petroleum and Petroleum Products(API MPMS Chap-ter8.3)

E123Specification for Apparatus for Determination of Water by Distillation

2.2API Standards:3

MPMS Chapter8.1Manual Sampling of Petroleum and Petroleum Products(ASTM Practice D4057)

MPMS Chapter8.2Automatic Sampling of Petroleum and Petroleum Products(ASTM Practice D4177)

MPMS Chapter8.3Mixing and Handling of Liquid Samples of Petroleum and Petroleum Products(ASTM Practice D5854)

MPMS Chapter10.2Determination of Water in Crude Oil by the Distillation Method(ASTM Test Method D4006) MPMS Chapter10.6Test Method for Water and Sediment in Fuel Oils by the Centrifuge Method(Laboratory Proce-dure)(ASTM Test Method D1796)

1This test method is under the jurisdiction of ASTM Committee D02on 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).

Current edition approved May1,2013.Published July2013.Originally approved in1921.Last previous edition approved in2010as D95–05(2010).DOI: 10.1520/D0095-13E01.

2For 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.

3Published as Manual of Petroleum Measurement Standards.Available from American Petroleum Institute(API),1220L.St.,NW,Washington,DC20005-4070, http://www.api.org..

*A Summary of Changes section appears at the end of this standard Copyright©ASTM International,100Barr Harbor Drive,PO Box C700,West Conshohocken,PA19428-2959.United States

3.Terminology

3.1Definitions:

3.1.1bituminous material,n—in petroleum technology ,a black or dark-colored very viscous liquid or semi-solid com-posed principally of high molecular weight condensed aromatic,or naphthenic compounds,or both.

4.Summary of Test Method

4.1The material to be tested is heated under reflux with a water-immiscible solvent,which co-distills with the water in the sample.Condensed solvent and water are continuously separated in a trap,the water settling in the graduated section of the trap and the solvent returning to the still.

5.Significance and Use

5.1A knowledge of the water content of petroleum products is important in the refining,purchase,sale,and transfer of products.

5.2The amount of water as determined by this test method (to the nearest 0.05or 0.1volume %,depending on the trap size used)may be used to correct the volume involved in the custody transfer of petroleum products and bituminous mate-rials.

5.3The allowable amount of water may be specified in contracts.

6.Solvent-Carrier Liquid

6.1A water-immiscible solvent-carrier liquid that is mis-cible in the material being tested (see Table 1)shall be used.6.1.1Aromatic Solvent—The following aromatic solvents are acceptable:

6.1.1.1Industrial Grade Xylene—(Warning—Flammable.Vapor harmful.)

6.1.1.2A blend of 20volume %industrial grade toluene and 80volume %industrial grade xylene.(Warning—Flammable.Vapor harmful.)

6.1.1.3Petroleum Naphtha or Coal Tar Naphtha,free of water,yielding not more than 5%distillates at 125°C (257°F)and not less than 20%at 160°C (320°F)and with a relative density (specific gravity)not lower than 0.8545at 15.56/15.56°C (60/60°F).(Warning—Extremely flammable.Harm-ful if inhaled.Vapors may cause fire.)

6.1.2Petroleum Distillate Solvent—A petroleum distillate solvent containing at least 2%(V/V)aromatics and with an initial boiling point (IBP)greater than 80°C (176°F);and a final boiling point (FBP)below 250°C (482°F)shall be used.

N OTE 3—Examples of suitable solvents include Types I and IV and Classes A and B of Specification D235.

N OTE 4—It is recommended to use a wide boiling range solvent with 10%boiling below 100°C to help to ensure an even distillation rate.

6.1.3Volatile Spirits Solvent—The following volatile spirits solvents are acceptable:

6.1.3.1Petroleum Spirit,with a boiling range from 100to 120°C (212to 248°F).(Warning—Flammable.Vapor harm-ful.)

6.1.3.2Iso-octane,of 95%purity or better.(Warning—Extremely flammable.Harmful if inhaled.Vapors may cause fire.)

6.2Solvent Blank—The water content of the solvent shall be determined by distilling an equivalent amount of the same solvent used for the test sample in the distillation apparatus and testing as outlined in Section 10.The blank shall be determined to the nearest scale division and used to correct the volume of water in the trap in Section 11.

7.Apparatus

7.1General—The apparatus comprises a glass or metal still,a heater,a reflux condenser,and a graduated glass trap.The still,trap,and condenser may be connected by any suitable method that produces a leakproof joint.Preferred connections are ground joints for glass and O-rings for metal to glass.Typical assemblies are illustrated in Fig.1,Fig.2,and Fig.3.The stills and traps should be chosen to cover the range of materials and water contents expected.On assembly,care shall be taken to prevent the joints from freezing or sticking.Always apply a very thin film of stopcock grease to prevent the glassware joints from seizing.

7.2Still—A glass or metal vessel with a short neck and suitable joint for accommodating the reflux tube of the trap shall be used.Vessels of 500,1000,and 2000-mL nominal capacity have proved satisfactory.

7.3Heater—A suitable gas burner or electric heater may be used with the glass still.A gas ring burner with ports on the inside circumference shall be used with the metal still.The gas ring burner shall be of such dimensions that it may be moved

TABLE 1Type of Solvent-Carrier Liquid to Use Versus Material to

Be Tested

Type of Solvent-Carrier Liquid

Material to be Tested

Aromatic asphalt,bitumen,tar,and related products Petroleum distillate fuel oil,lubricating oil,lubricating oil additives

Volatile spirits

greases

FIG.1Typical Assembly with Glass

Still

up and down the vessel when testing materials that are likely to foam or solidify in the still.

7.4Glassware—Dimensions and descriptions of typical glassware for use in this test method are provided in Specifi-cation E123.

N OTE 5—Instead of standardizing on a particular apparatus specifica-tion with respect to dimensions and style,a given apparatus will be deemed satisfactory when accurate results are obtained by the standard addition technique described in Section 9.

8.Sampling

8.1Sampling is defined as all steps required to obtain an aliquot of the contents of any pipe,tank,or other system and to place the sample into the laboratory test container.Only representative samples obtained as specified in Practices D4057(API MPMS Chapter 8.1)and D4177(API MPMS Chapter 8.2)shall be used for this test method.

8.2The size of the test portion should be based on the expected water content of the sample,such that the water yield does not exceed the capacity of the trap (unless a trap with a stopcock is used permitting excess water to be withdrawn into a graduated cylinder).

8.3Practice D5854(API MPMS Chapter 8.3)contains information on sampling and homogenization efficiency of unknown mixers.This test method should not be followed without strict adherence to Practice D5854(API MPMS Chapter 8.3).9.Verification

9.1The accuracy of the graduation marks on the trap shall be certified or verified,using only national or international standards,such as National Institute of Standards and Technol-ogy (NIST)4traceable equipment.Verification shall be with a traceable 5mL Micro Burette or Micro Pipette,readable to the nearest 0.01mL.

9.1.1In styles A,B,C,and D,as specified in Table 2(Table 1in Specification E123),each subdivision (that is,0.1mL through 1.0mL)in the conical portion of the tube shall be verified.Thereafter,each major subdivision (that is,2.0mL,3.0mL,4.0mL,and up to the total volume of the trap)shall be verified.

9.1.2In styles E and F,as specified in Table 2,each major subdivision (0.1mL,1.0mL,2.0mL,4.0mL,and 5.0mL in the case of Style E;0.05mL,0.5mL,1.0mL,1.5mL,and 2.0mL in the case of Style F)shall be verified.

9.2The entire glassware assembly shall be verified prior to first use and at a regular frequency thereafter as follows.9.2.1Put 400mL of dry (0.02%water maximum)xylene or the solvent to be utilized in the analysis of unknown samples into the apparatus and test in accordance with Section 10.When complete,discard the contents of the trap and add the volume of water as specified as first test in Table 3directly to the distillation flask and test in accordance with Section 10.9.2.2Repeat the test in 9.2.1,and add the volume specified as second test in Table 3directly to the flask.The assembly of the apparatus is satisfactory only if the trap readings are within the tolerances specified in Table 3.

9.3A reading outside the permissible limits suggests a malfunction resulting from vapor leaks,too rapid boiling,inaccuracies in calibration of the trap,or ingress of extraneous moisture.Eliminate these factors before repeating the verifica-tion.

10.Procedure

N OTE 6—The precision of this test method will be affected by water droplets adhering to surfaces in the apparatus and therefore not settling into the water trap to be measured.To minimize the problem,all apparatus must be cleaned chemically at least daily to remove surface films and debris,which hinder free drainage of water in the test apparatus.More frequent cleaning is recommended if the nature of samples being run causes persistent contamination.

10.1Measure a suitable amount of sample to an accuracy of 61%and transfer it to the still.

10.2Measure ordinary liquid samples in a graduated cylin-der of an appropriate size.Rinse the material adhering to the cylinder with one 50-mL and two 25-mL portions of the solvent-carrier liquid (see Section 6and Table 1).Drain the cylinder thoroughly after the sample transfer and each rinsing.10.3Weigh solid or viscous materials directly into the still and add 100mL of the selected solvent-carrier liquid.In cases of material with a low-water content when large samples must be used,a solvent-carrier liquid volume in excess of 100mL may be necessary.

10.4Glass beads or other boiling aids may be added,if necessary,to reduce bumping.

10.5Assemble the components of the apparatus,as illus-trated in Fig.1,Fig.2,and Fig.3,choosing the trap in

4

National Institute of Standards and Technology (NIST),100Bureau Dr.,Stop 1070,Gaithersburg,MD 209-1070,

http://www.nist.gov.

FIG.2Two-millilitre Receiver Showing Alternative Connections to

Glass

Still

N OTE1—Trap shall be15to16mm in inside diameter.

FIG.3Typical Assemblies with Metal Still

accordance with the expected water content of the sample and making all connections vapor and liquid tight.If a metal still with a removable cover is used,insert a gasket of heavy paper,moistened with solvent,between the still body and the cover.The condenser tube and trap must be chemically clean to ensure free drainage of water into the bottom of the trap.Insert a loose cotton plug in the top of the condenser to prevent condensation of atmospheric moisture inside it.Circulate cold water through the jacket of the condenser.

10.6Apply heat to the still,adjusting the rate of boiling so that condensed distillate discharges from the condenser at the rate of two to five drops per second.If the metal still is used,start heating with the ring burner about 76mm (3in.)above the bottom of the still and gradually lower the burner as the distillation proceeds.Continue distillation until no water is visible in any part of the apparatus except in the trap and the volume of water in the trap remains constant for 5min.If there is a persistent ring of water in the condenser tube,carefully increase the rate of distillation or cut off the condenser water for a few minutes.

10.7When the evolution of water is complete,allow the trap and contents to cool to room temperature.Dislodge any drops of water adhering to the sides of the trap with a glass or polytetrafluoroethylene (PTFE)rod or other suitable means and transfer them to the water layer.Read the volume of the water in the trap to the nearest scale division.

10.8A solvent blank shall be established,as outlined in 6.2.11.Calculation

11.1Calculate the water in the sample,as weight or volume percent,in accordance with the basis on which the sample was taken,as follows:

11.1.1Water,%(V/V)=

~Volume in water trap,mL !2~Water in solvent blank,mL !

3100

(1)

11.1.2Water,%(V/m)=

~Volume of water in trap,mL !2~Water in solvent blank,mL !

3100

(2)

12.Report

12.1Report the results as the water content to the nearest 0.05%if the 2-mL receiver has been used and to the nearest 0.1%if the 10-mL or 25-mL receiver has been used and to the nearest subdivision if a 5-mL receiver has been used with a 100-mL or 100-g sample.13.Precision and Bias

13.1Precision—The criteria described in 13.1.1and 13.1.2should be used to judge the acceptability of results when using the 10or 25-mL traps.The precision when using the 2-mL trap or a 5–mL trap has not been established.

N OTE 7—Practice D6300was not used in obtaining precision data.

13.1.1Repeatability—The difference between successive test results,obtained by the same operator with the same apparatus under constant operating conditions on identical test material,would,in the long run,in the normal and correct operation of the test method,exceed the values in Table 4in only one case in twenty.

TABLE 2Specifications and Sizes of Traps

Description

Style Top of Graduated Tube Bottom of Graduated Tube Bottom of Vapor Tube Size of Trap

mL

Range mL Smallest Scale Division,mL Scale Error Maximum,

mL A ST Joint Conical ST Joint 100to 1.00.10.05>1.0to 10.00.20.1B ST Joint Conical ST Joint 250to 1.00.10.05C ST Joint Conical Plain 25>1.0to 250.20.1D ST Joint Conical Plain 25 1.0to 250.20.1E

ST

Joint

Round

ST Joint

50to 5.00.10.0550to 5.00.050.025100to 10.00.10.1F ST Joint Round ST Joint

2

0to 2.0

0.05

0.025

TABLE 3Permissible Limits in Millilitres

Capacity of Receiver at 20°C Volume of Water Added to Flask at

20°C

Permissible Limits for Recovered Water at

20°C

Round trap

21st Test 11±0.0522nd Test 1.9 1.9±0.055(0.05mL subdivisions)1st Test 11±0.055(0.05mL subdivisions)2nd Test

4.5

4.5±0.05

5(0.1mL subdivisions)1st Test 11±0.15(0.1mL subdivisions)

2nd Test

4.5

4.5±0.1

101st Test 55±0.1102nd Test 99±0.1

Conical trap

101st Test 11±0.110

2nd Test 99±0.2251st Test 1212±0.225

2nd Test

24

24±

0.2

13.1.2Reproducibility—The difference between two single and independent test results obtained by different operators working in different laboratories on identical test material,

would,in the long run,in the normal and correct operation of the test method,exceed the values in Table 4in only one case in twenty.

13.2Bias—As there is no accepted reference material suit-able for determining bias for the procedure described in this test method for measuring water in petroleum products and bituminous materials by distillation,no statement about bias is made.14.Keywords

14.1bituminous materials;distillation;petroleum products;solvent carrier liquid;water by distillation;water content

SUMMARY OF CHANGES

Subcommittee D02.02has identified the location of selected changes to this standard since the last issue (D95–05(2010))that may impact the use of this standard.

(1)Added Specification D235to subsection 2.1.(2)Updated 6.1,6.1.2,and Table 1.

(3)Added Note 3and Note 4.

ASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentioned in this standard.Users of this standard are expressly advised that determination of the validity of any such patent rights,and the risk of infringement of such rights,are entirely their own responsibility.

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TABLE 4Precision

Type Water Collected,

mL

Difference,mL

Repeatability

0.0–1.00.1

1.1–25

0.1mL or 2%of the mean,whichever is greater

Reproducibility

0.0–1.00.2

1.1–25

0.2mL or 10%of the mean,whichever is

greater