ASTM D5846-99

NOTICE: This standard has either been superseded and replaced by a new version or discontinued.
Contact ASTM International (www.astm.org) for the latest information.
Designation: D 5846 – 99 An American National Standard
Standard Test Method for
Universal Oxidation Test for Hydraulic and Turbine Oils
Using the Universal Oxidation Test Apparatus
This standard is issued under the fixed designation D 5846; 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 (e) indicates an editorial change since the last revision or reapproval.
1. Scope D 943 Test Method for Oxidation Characteristics of Inhib-
ited Mineral Oils
1.1 This test method covers a procedure for evaluating the
D 974 Test Method for Acid and Base Number by Color-
oxidation stability of petroleum base hydraulic oils and oils for
Indicator Titration
steam and gas turbines.
D 3339 Test Method for Acid Number of Petroleum Prod-
1.2 This test method was developed to evaluate the oxida-
ucts by Semi-Micro Color Indicator Titration
tion stability of petroleum base hydraulic oils and oils for
D 4057 Practice for Manual Sampling of Petroleum and
steam and gas turbines.
Petroleum Products
1.2.1 Rust and oxidation inhibited hydraulic, anti-wear hy-
D 4740 Test Method for Stability and Compatibility of
draulic and turbine oils of ISO 32–68 viscosity were used to
Residual Fuels by Spot Test
develop the precision statement. This test method has been
D 4871 Guide for Universal Oxidation/Thermal Stability
used to evaluate the oxidation stability of fluids made with
Test Apparatus
synthetic basestock and in-service oils; however, these fluids
D 5770 Test Method for Semi-Quantitative Micro Determi-
have not been used in cooperative testing to develop precision
nation of Acid Number of Used Lubricating Oils
data.
2.2 Institute of Petroleum Standard:
1.3 The values stated in SI units are to be regarded as the
IP 2546 Practice for Sampling of Petroleum Products;
standard. The values given in parentheses are for information
alternate to Practice D 4057
only.
2.3 British Standard:
1.4 This standard does not purport to address all of the
BS 1829 Specification for Carbon Steel Wire; alternate to
safety concerns, if any, associated with its use. It is the
Specification A 510
responsibility of the user of this standard to establish appro-
2.4 ASTM Adjuncts:
priate safety and health practices and determine the applica-
Reference Spot Sheet (Test Method D 4740), for visual
bility of regulatory limitations prior to use. Identified hazard-
rating of blotter spots
ous chemicals are listed in 7.2, 7.5, and 7.7. Before using this
test method, refer to suppliers’ safety labels, Material Safety
3. Terminology
Data Sheets, and other technical literature.
3.1 Definitions of Terms Specific to This Standard:
2. Referenced Documents 3.1.1 oxidation life, n—of an oil, the time in hours required
for degradation of the oil under test.
2.1 ASTM Standards:
3.1.2 inhibited mineral oil, n—a petroleum oil containing
A 510 Specification for General Requirements for Wire
2 additives to retard oxidation.
Rods and Coarse Round Wire, Carbon Steel
3.1.3 universal oxidation test, n—the apparatus and proce-
B 1 Specification for Hard-Drawn Copper Wire
4 dures described in Guide D 4871.
D 329 Specification for Acetone
D 664 Test Method for Acid Number of Petroleum Products
4. Summary of Test Method
by Potentiometric Titration
4 4.1 An oil sample is contacted with air at 135°C in the
D 770 Specification for Isopropyl Alcohol
presence of copper and iron metals. The acid number and spot
forming tendency of the oil are measured daily. The test is
This test method is under the jurisdiction of ASTM Committee D-2 on
Petroleum Products and Lubricantsand is the direct responsibility of Subcommittee
D02.09.ODon Lubricants. Annual Book of ASTM Standards, Vol 05.02.
Current edition approved Dec. 10, 1999. Published January 2000. Annual Book of ASTM Standards, Vol 05.03.
Originally published as D 5846–95. Last previous edition D 5846–98. Available from the Institute of Petroleum, 61 New Cavendish St., London,
Annual Book of ASTM Standards, Vol 01.03. W1M 8AR, England.
3 9
Annual Book of ASTM Standards, Vol 02.03. Available from British Standards Institute, 2 Park St., London, England
Annual Book of ASTM Standards, Vol 06.04. W1A2B5.
5 10
Annual Book of ASTM Standards, Vol 05.01. Available from ASTM Headquarters. Order PCN 12-427810.00.
Copyright © ASTM, 100 Barr Harbor Drive, West Conshohocken, PA 19428-2959, United States.
D 5846
terminated when the oxidation life of the oil has been reached. 6.1.1 Test cells are maintained at a constant elevated tem-
4.2 The oil is considered to be degraded when either its acid perature by means of a heated aluminum block which sur-
number (measured by Test Methods D 974 or D 664) has rounds each test cell.
increased by 0.5 mg KOH/g over that of new oil; or when the
6.1.2 The test cells shall fit into the block to a depth of 225
oil begins to form insoluble solids so that when a drop of oil is
6 5 mm. When centered, the side clearance of the 38 mm
placed onto a filter paper it shows a clearly defined dark spot
outside diameter glass tube to the holes in the aluminum block
surrounded by a ring of clear oil.
shall not exceed 1 mm in any direction.
6.2 Temperature Control System, as shown at lower left in
5. Significance and Use
Fig. 1, and as further described in Guide D 4871, to maintain
5.1 Degradation of hydraulic fluids and turbine oils, because
the test oils in the heating block at 135 6 0.5°C for the duration
of oxidation or thermal breakdown, can result in the formation
of the test.
of acids or insoluble solids and render the oil unfit for further
6.3 Gas Flow Control System, as shown in the upper left in
use.
Fig. 1, and as further described in Guide D 4871, to provide dry
5.2 This test method can be used to estimate the relative
air at a flow rate of 3.0 6 0.5 L/h to each test cell.
oxidation stability of petroleum-base oils. It should be recog-
6.3.1 A gas flow controller is required for each test cell.
nized that correlation between results of this test and the
6.3.2 Flowmeters shall have a scale length sufficiently long
oxidation stability in use can vary markedly with service
to permit accurate reading and control to within 5 % of full
conditions and with various oils.
scale.
6. Apparatus
6.3.3 The total system accuracy shall meet or exceed the
6.1 Heating Block, as shown on the right in Fig. 1, and as following tolerances: Inlet pressure regulator within 0.34 kPa
further described in Guide D 4871, to provide a controlled (0.05 psig) of setpoint; total flow control system reproducibil-
constant temperature for conducting the test. ity within 7 % of full scale; repeatability of measurement
FIG. 1 Apparatus, Showing Gas Flow Control System, Temperature Control System, and Heating Block
D 5846
within 0.5 % of full scale. D 4871. Alternate apparatus designs for sample heating and
for temperature and flow control shall be acceptable provided
6.4 Oxidation Cell, borosilicate glass, as shown in Fig. 2,
they are shown to maintain temperature and gas flow within the
and as further described in Guide D 4871. This consists of a
specified limits.
test cell of borosilicate glass, standard wall; 38 mm outside
diameter, 300 6 5-mm length, with open end fitted with a
7. Reagents and Materials
34/45 standard-taper, ground-glass outer joint.
7.1 Abrasive Cloth, silicon carbide, 100-grit with cloth
6.5 Gas Inlet Tube, as shown in Fig. 2, and as further
backing.
described in Guide D 4871. This consists of an 8-mm outside
7.2 Acetone, conforming to Specification D 329.
diameter glass tube, at least 455 long, lower end with fused
(Warning—Acetone is flammable and a health hazard.)
capillary 1.5 to 3.5 mm inside diameter. The capillary bore
7.3 Air, dry with dew point −60°.
shall be 15 6 1 mm long. The lower tip is cut at a 45° angle.
7.4 Electrolytic Copper Wire, 1.63 mm in diameter (No. 14
6.6 Basic Head, as shown in Fig. 2, and as further described
American Wire Gage or No. 16 Imperial Standard Wire Gage),
in Guide D 4871. This is an air condenser, with 34/45 standard- 99.9 % purity, conforming to Specification B 1, is preferred.
taper, ground-glass inner joint, opening for gas inlet tube, 7.5 Heptane, knock-test grade, conforming to the following
requirements: (Warning—n—Heptane is flammable and a
septum port for sample withdrawal, and exit tube to conduct
health hazard.)
off-gases and entrained vapors. Overall length shall be 125 6
Density at 20°C 0.6826 to 0.6839
5 mm.
Refractive index at 20°C 1.3876 to 1.3879
6.7 Test precision was developed using the universal
Solidification temperature, min −90.72°
Distillation 50 % shall distill between 98.38° and
oxidation/thermal stability test apparatus described in Guide
98.48°. Temperature rise between 20
and 80 % recovered shall be 0.20° max
NOTE 1—Warning: n-Heptane is flammable and a health hazard.
7.6 Low-Metalloid Steel Wire, 1.59 mm in diameter (No. 16
Washburn and Moen Gage). Carbon steel wire, soft bright
annealed and free from rust, of Grade 1008 as described in
Specification A 510, is preferred. Similar wire conforming to
British Standard 1829 is also satisfactory.
7.7 Propanol-2 (iso-Propyl Alcohol), conforming to Speci-
fication D 770 (Warning—iso-Propyl alcohol is flammable
and a health hazard.
7.8 Test Paper, chromatographic or filter paper, cellulose,
medium porosity, qualitative or quantitative grade. Cut the
paper into 50 mm squares or use as larger sheets, ruled with
hard pencil into 50 mm squares without cutting.
8. Sampling
8.1 Samples for this test can come from tanks, drums, small
containers, or operating equipment. Therefore, use the appli-
cable apparatus and techniques described in Practice D 4057 or
IP 2546 to obtain suitable samples.
8.2 Special precautions to preserve the integrity of a sample
will not normally be required. Follow good laboratory practice.
Avoid undue exposure of samples to sunlight or strong direct
light. Use only samples that are homogeneous on visual
inspection.
9. Preparation of Apparatus
9.1 Cleaning Glassware:
A standard commercial apparatus has been found satisfactory for the purpose
of this test method. This apparatus, including heating block, temperature control
system, flow control system and glassware, is available from Falex Corp., 1020
Airpark Dr., Sugar Grove, IL 60554. Glassware for the universal oxidation test
apparatus is also available from W. A. Sales, Ltd., 419 Harvester Court, Wheeling,
IL 60090.
Whatman 1 grade, available in 57 by 46 cm sheets, have been found
FIG. 2 Test Cell, Including Oxidation Cell, Gas Inlet Tube, Basic satisfactory for this test method. Paper sheets should be stored without folding,
Head, and Finished Catalyst Coil rolling or bending, in a tightly closed container.
D 5846
9.1.1 Clean new glassware by washing with a hot detergent 10.3 Place a cleaned catalyst coil in the oil and fit the basic
solution, using a bristle brush; rinse thoroughly with tap water. head and gas delivery tube into the test cell so that the tip of the
When any visible deposits remain, soak with hot detergent gas delivery tube rests on the bottom of the test cell inside the
solution and repeat rinses. After final cleaning by soaking with catalyst coil, as shown in Fig. 3.
a suitable cleaning solution rinse thoroughly with tap water 10.4 Insert the test cell into the preheated constant tempera-
then distilled water and dry at room temperature or in an oven. ture block. Wait 0.5 to 1.0 h for the oil to warm to 135 6 0.5°C.
A final rinse with iso-propyl alcohol or acetone will hasten 10.5 Connect an air delivery tube from the flow control
drying at room temperature. system to the gas inlet tube and adjust the flowmeter control to
9.1.2 Clean used glassware immediately following the end deliver dry air at 3 6 0.5 L/h. Record this time as the start of
of a test. Drain the used oil completely. Rinse all glassware the test.
with heptane to remove traces of oil. Then clean the glassware 10.6 Recheck the air flow after the test is underway and at
by the procedure described in 9.1.1 before re-use. least once daily during the test. Adjust to maintain the air flow
9.2 Cleaning Catalyst: as needed.
9.2.1 Clean equal lengths of iron and copper wire with wads 10.7 Withdraw a 2.0 6 0.2 g oil sample for determination of
of absorbent cotton wet with heptane or other saturated acid number at one-day intervals after the start of the test.
paraffinic solvent of comparable boiling point. Follow by 10.7.1 Additional samples are taken for acid number deter-
abrasion with 100-grit silicon carbide abrasive cloth until fresh mination if desired. More frequent sampling at a time when the
metal surfaces are exposed. Wipe with dry absorbent cotton to acid number is increasing rapidly is helpful to more precisely
remove loose particles of metal and abrasives. Repeat with determine the time to a 0.5 acid number increase.
fresh cotton until no particles are visible. In the following 10.8 Determine the acid number by Test Method D 3339 or
operations, handle the catalyst with clean gloves (cotton, D 5770; alternate test methods such as Test Methods D 664 or
rubber, or plastic) to prevent contamination from oils on the
skin.
Exhaust gases need not be collected. Vent exhaust gases properly.
9.2.2 One procedure for preparing clean catalyst wire is to
cut 0.50 6 0.01 m lengths of wire. Hold one end of the wire
tightly with a pair of clean pliers or in a vise while cleaning
with the abrasive cloth. Reverse ends of the wire and repeat.
9.2.3 Alternately, clean a longer length of wire (3 to 5 m)
and then cut 0.50 6 0.01 m lengths from the clean wire.
9.3 Preparation of Catalyst Coil:
9.3.1 Twist the iron and copper wires tightly together at one
end for three twists. With the two wires parallel, wind the wires
around a cylindrical mandrel to produce a single coil 15.9 to
16.5 mm in inside diameter. The mandrel described in Test
Method D 943 is satisfactory, but other cylindrical metal or
wood stock can be used. Remove the coil from the mandrel and
secure the free ends with three twists. Bend the twisted ends to
conform to the shape of the spiral coil. Stretch the coil to
produce a finished coil with an overall length of 80 6 8mmas
shown in Fig. 2.
9.3.2 Store the catalyst coil in a dry, inert atmosphere until
use. For storage up to 24 h, the coil can be stored in heptane.
Before use, inspect stored coils to ensure that no corrosion
products or contaminating materials are present.
9.4 Use a fresh catalyst coil for each test. Do not reuse coils.
10. Procedure
10.1 A
...