ASTM D6278-20a

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Designation: D6278 − 20 D6278 − 20a
Standard Test Method for
Shear Stability of Polymer Containing Fluids Using a
European Diesel Injector Apparatus
This standard is issued under the fixed designation D6278; 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.
1. Scope*
1.1 This test method covers the evaluation of the shear stability of polymer-containing fluids. The test method measures the
percent viscosity loss at 100 °C of polymer-containing fluids when evaluated by a diesel injector apparatus procedure that uses
European diesel injector test equipment. The viscosity loss reflects polymer degradation due to shear at the nozzle.
NOTE 1—Test Method D2603 has been used for similar evaluation of shear stability; limitations are as indicated in the significance statement. No
detailed attempt has been undertaken to correlate the results of this test method with those of the sonic shear test method.
NOTE 2—This test method uses test apparatus as defined in CEC L-14-A-93. This test method differs from CEC-L-14-A-93 in the period of time
required for calibration.
NOTE 3—Test Method D5275 also shears oils in a diesel injector apparatus but may give different results.
NOTE 4—This test method has different calibration and operational requirements than withdrawn Test Method D3945.
NOTE 5—Test Method D7109 is a similar procedure that measures shear stability at both 30 and 90 injection cycles. This test method uses 30 injection
cycles only.
1.2 The values stated in SI units are to be regarded as the standard.
1.2.1 Exception—Non-SI units are provided in parentheses.
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, health, and environmental practices and determine the applicability of
regulatory limitations prior to use. Specific precautionary statements are given in Section 8.
1.4 This international standard was developed in accordance with internationally recognized principles on standardization
established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued
by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
2. Referenced Documents
2.1 ASTM Standards:
D445 Test Method for Kinematic Viscosity of Transparent and Opaque Liquids (and Calculation of Dynamic Viscosity)
D2603 Test Method for Sonic Shear Stability of Polymer-Containing Oils
D5275 Test Method for Fuel Injector Shear Stability Test (FISST) for Polymer Containing Fluids
D6299 Practice for Applying Statistical Quality Assurance and Control Charting Techniques to Evaluate Analytical Measure-
ment System Performance
D7042 Test Method for Dynamic Viscosity and Density of Liquids by Stabinger Viscometer (and the Calculation of Kinematic
Viscosity)
D7109 Test Method for Shear Stability of Polymer-Containing Fluids Using a European Diesel Injector Apparatus at 30 Cycles
and 90 Cycles
2.2 Coordination European Council (CEC) Standard:
CEC L-14-A-93 Evaluation of the Mechanical Shear Stability of Lubricating Oils Containing Polymers
3. Terminology
3.1 Definitions:
This test method is under the jurisdiction of ASTM Committee D02 on Petroleum Products, Liquid Fuels, and Lubricants and is the direct responsibility of Subcommittee
D02.07 on Flow Properties.
Current edition approved May 1, 2020June 1, 2020. Published May 2020June 2020. Originally approved in 1998. Last previous edition approved in 20172020 as
ɛ1
D6278 – 17D6278 – 20. . DOI: 10.1520/D6278-20.10.1520/D6278-20A.
For 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.
Available from CEC Secretariat, Interlynk Administrative Services, Ltd., Lynk House, 17 Peckleton Lane, Desford, Leicestershire, LE9 9JU, United Kingdom.
*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
D6278 − 20a
3.1.1 kinematic viscosity, n—a measurethe ratio of the resistance to flow of a fluid under gravity.dynamic viscosity (η) to the
density (ρ) of a liquid at a given temperature.
3.2 Definitions of Terms Specific to This Standard:
3.2.1 calibration pressure, n—the recorded gauge pressure when calibration fluid RL233 undergoes a viscosity loss of
2 2
2.70 mm /s to 2.90 mm /s when the recorded gauge pressure is within the range of 13.0 MPa to 18.0 MPa.
3.2.2 percent viscosity loss, n—viscosity loss, as defined in 3.2.3, divided by the pre-sheared viscosity, and reported as a percent.
3.2.3 viscosity loss, n—the loss in viscosity determined from the difference in kinematic viscosity at 100 °C of pre-sheared and
post-sheared fluid.
4. Summary of Test Method
4.1 A polymer-containing fluid is passed through a diesel injector nozzle at a shear rate that causes polymer molecules to
degrade. The resultant degradation reduces the kinematic viscosity of the fluid under test. The percent viscosity loss is a measure
of the mechanical shear stability of the polymer-containing fluid.
5. Significance and Use
5.1 This test method evaluates the percent viscosity loss for polymer-containing fluids resulting from polymer degradation in
the high shear nozzle device. Thermal or oxidative effects are minimized.
5.2 This test method is used for quality control purposes by manufacturers of polymeric lubricant additives and their customers.
5.3 This test method is not intended to predict viscosity loss in field service in different field equipment under widely varying
operating conditions, which may cause lubricant viscosity to change due to thermal and oxidative changes as well as by the
mechanical shearing of polymer. However, when the field service conditions, primarily or exclusively, result in the degradation of
polymer by mechanical shearing, there may be a correlation between the results from this test method and results from the field.
6. Apparatus
6.1 The apparatus consists of a fluid reservoir, a double-plunger pump with an electric motor drive, an atomization chamber with
a diesel injector spray nozzle, and a fluid cooling vessel, installed in an area with an ambient temperature of 20 °C to 25 °C (68 °F
to 77 °F). Fig. A1.1 shows the schematic representation of equipment.
6.1.1 Fluid Reservoir, In Fig. A1.1, the fluid reservoir (7) is open on the top, has approximately a 250 mL capacity with
gradation of a maximum of 5 mL, has a 45 mm (1.772 in.) inner diameter, and is calibrated in units of volume. It is fitted with an
internal fluid distributor as detailed in Fig. A1.2. A 40 mm (1.575 in.) diameter watch glass with serrated edges is an acceptable
distributor plate. The distributor reduces the tendency of fluid channeling. Temperature is measured by a thermometer suspended
in the center of the fluid reservoir. The bottom of the thermometer bulb shall be 10 mm to 15 mm above the entrance to the drain
tube opening. Other temperature-measuring equipment positioned at the same location may also be used. The outlet is equipped
with a three-way stopcock (8). The three-way stopcock is of a cone type with a nonexchangeable solid plug with an 8 mm
(0.315 in.) nominal bore size. Transparent, plastic tubing (10) in Fig. A1.1, is used to connect the three-way stopcock to the pump
inlet.
6.1.2 Double-Plunger Injection Pump, In Fig. A1.1 (11) is defined as Bosch PE 2 A 90D 300/3 S2266. This pump is equipped
with a stroke counter (15), venting screw (14), and flow rate adjusting screw (12).
6.1.3 Injection Pump, driven by a three-phase electric motor (13) in Fig. A1.1, rated at a speed of 925 r ⁄min 6 25 r ⁄min.
6.1.3.1 This motor runs at 925 r ⁄min on the 50 Hz current prevalent in Europe; it will run at approximately 1100 r ⁄min on 60 Hz
current. The 1100 r ⁄min speed is not acceptable in this procedure. A suitable means shall be taken to ensure the prescribed
925 r ⁄min 6 25 r ⁄min speed to the injection pump. One acceptable method is to use a 6 to 5 speed reducer.
6.1.4 Outlet of Injection Pump, connected to the atomization chamber using high pressure steel tubing. The atomization
chamber (2) in Fig. A1.1 is defined in more detail in Fig. A1.3. To minimize foam generation, the spray chamber is designed so
that the fluid under test exits from the nozzle into a chamber filled with the test fluid. A drain tube (17) fitted with a two-way
stopcock is included to minimize contamination from the previous test during the system cleaning steps. The diesel injector nozzle
is a Bosch DN 8 S 2-type pintle nozzle injector, number 0434 200 012, installed in a Bosch KD 43 SA 53/15 nozzle holder. The
nozzle holder includes a filter cartridge.
NOTE 6—Take great care to avoid damage to the precision parts of the fuel injection equipment (the plunger and barrel in the pump and the nozzle
valve assembly). Service work on the equipment should be performed by a diesel fuel injector pump specialist or with reference to the manufacturer’s
service manual.
NOTE 7—An unusual rapid rise in gauge pressure during testing may signify filter blockage. When this occurs, the filter cartridge shall be replaced.
6.1.5 A pressure sensing device (18), such as a glycerol-filled pressure gauge or electronic, digital display pressure indicator,
shall be installed and separated from the line by a pressure snubber or needle valve to suitably dampen pressure surges. The
The number in parentheses refers to the legend in Fig. A1.1.
Repair Instructions for Diesel Injection Pumps Size A, B, K and Z, Bulletin WJP 101/1 B EP, Robert Bosch GmbH, 2800 South 25th Ave., Broadview, IL 60153.
D6278 − 20a
pressure sensing device shall be able to take readings with a display resolution of at least 0.1 MPa when a glycerol-filled pressure
gauge is being used, or to 0.01 MPa when an electronic pressure device is employed. The pressure device shall be occasionally
pressure tested to ensure accuracy.
6.1.6 Fluid Cooling Vessel, ((5) in Fig. A1.1), used to maintain the specified temperature of the test fluid, as indicated at the
outlet of the fluid reservoir. This vessel is a glass container with exterior cooling jacket constructed so that the heat transfer surface
of the jacket is spherical. The exterior jacket diameter, d , is approximately 50 mm (1.969 in.). The interior heat transfer surface,
d , is approximately 25 mm (0.984 in.) in diameter. The overall length, L, is approximately 180 mm (7.087 in.). A distributor plate,
similar in design to the distributor plate in the fluid reservoir, is positioned in the upper portion of the fluid cooling vessel to ensure
contact between the fluid and the cooling surface. The discharge from the fluid cooling vessel is through a three-way stopcock of
the same design used on the discharge of the fluid reservoir. If using a rate-dependent chiller, the exterior cooling jacket shall be
supplied with an adjustable volume of cold water.
6.2 Viscometer—Any viscometer and bath meeting the requirements of Test Method D445 or D7042. Whichever method is
chosen, that same method must be used for the before and after samples as well as the calibration samples.
7. Materials
7.1 Diesel Fuel (No. 2), initially required to adjust the diesel injector nozzle valve opening pressure.
7.2 Calibration Fluid RL233, used to ensure that when the apparatus is adjusted to within a prescribed pressure range, the
correct viscosity loss is obtained.
NOTE 8—RL233 meets the requirements of this test method and is acceptable during a transition period between suppliers. See research report for
details.
8. Hazards
8.1 Warning—Use a safety shield between the high-pressure components and the operator during use of equipment.
8.2 Precaution—During operation, the line between the pump and nozzle, ((16) in Fig. A1.1), is under a pressure of at least
13.0 MPa (130 bar, or 1885 psi). Pressures above the upper limit of 18.0 MPa (180 bar or 2611 psi) are possible if filter plugging
occurs. Shut off the pump prior to tightening any fitting that is not properly sealed.
9. Sampling
9.1 Approximately 600 mL of fluid is needed per test.
9.2 The test fluid shall be at room temperature, uniform in appearance, and free of any visible insoluble material prior to placing
in the test equipment.
9.3 Water and insolubles shall be removed before testing, or filter blocking and nozzle wear may occur. Filter blocking can be
detected by a sudden change in gauge pressure. The transport of insolubles to the shear zone will shorten nozzle life.
10. Calibration and Standardization
10.1 Nozzle Adjustments—If the nozzle to be used is new or has not been pre-calibrated, adjust the diesel injector nozzle holder
with the nozzle in place. Adjust the nozzle using diesel fuel and a nozzle tester so that the valve opening pressure is 13.0 MPa
(1885 psi) under static conditions. If the nozzle has been pre-calibrated with RL233 calibration oil, adjust the valve opening
pressure to the calibration pressure prescribed, which must be between 13.0 MPa and 18.0 MPa (2611 psi).
10.1.1 Install the nozzle and the nozzle holder in the test apparatus. The pintle/spray nozzle shall be tightly fitted in the chamber
to avoid leakage of oil around the external surface of the spray nozzle.
10.2 Measurement of Residual Undrained Volume, V :
res
10.2.1 The residual undrained oil volume of the system is the volume of the system between the three-way stopcock below the
fluid reservoir (8) in Fig. A1.1, and the injector nozzle orifice (1). V does not include the atomization chamber volume. When
res
the residual undrained volume is known, go to 10.4.
10.2.2 To determine residual undrained volume, first remove as much fluid as possible by briefly running the pump.
10.2.3 Remove the high-pressure lines (16) in Fig. A1.1, and drain. Remove the plug at the end of the pump gallery to drain
the remaining oil in the pump. Drain atomization chamber (2).
10.2.4 Reassemble the system and close all drains. The upper three-way stopcock (6) shall be open to the lower reservoir (7)
and the lower three-way cock (8) shall be open to the pump suction (10).
10.2.5 Add 170 mL of RL233 calibration oil to the lower reservoir (7) and observe the level. Start the pump and run for several
minutes until the oil is transparent and free of suspended air.
Supporting data have been filed at ASTM International Headquarters and may be obtained by requesting Research Report RR:D02-1629. Contact ASTM Customer
Service at service@astm.org.
D6278 − 20a
10.2.6 Stop the pump. Drain the fluid in the atomization chamber into a beaker and then pour the fluid back into the lower
reservoir; draining to waste will result in an error in the measurement of V . Allow the system to drain for 20 min and free air
res
trapped in the transparent connecting tube between the lower reservoir and pump.
10.2.7 Observe the difference in oil level in the lower reservoir compared to that noted in 10.2.5. Record this difference as the
residual volume, V .
res
NOTE 9—Undrained residual volumes of 15 mL to 30 mL have been reported by various users of this test. V measurements in excess of this may
res
occur when fluid in the atomization chamber is not poured back into the lower reservoir as in 10.2.6, or if the length of line (10) is excessive.
10.2.8 Calculate the run volume, V , which is the subtractive difference between 170 mL and V .
run res
10.3 Warm-up—A half-hour warm up period is required before proceeding to calibrate with RL233. Set the stroke counter
shut-off to 30 times n strokes, and start the pump.
NOTE 10—This warm-up period is only required for the first within-day calibration.
10.4 Cleaning the Apparatus, Setting the Stroke Counter, and Adjusting the Pump Stroke:
10.4.1 Drain residual oil by way of drain line (19) from the atomization chamber into a waste container. Drain fluid in the
cooling jacket by means of stopcock (6) (Fig. A1.1) and the fluid reservoir by means of stopcock (8), into suitable waste containers.
10.4.2 After fluid has drained, leave the stopcock on the drain line to the atomization chamber open and the three-way stopcock
(6) positioned so that fluid in the cooling jacket drains to a waste container. Position stopcock (8) so that the drain is closed but
the fluid reservoir is open to pump suction through line (10). Add a minimum of 50 mL of RL233 to the fluid reservoir.
NOTE 11—Steps 10.4.2 – 10.4.7 are representative of the first and second purges with 50 mL fluid that are needed to remove used oil from the apparatus
prior to calibration and testing. For these steps, the stopcock below the atomization chamber and cooling jackets are set so that oil will flow into waste
containers.
10.4.3 Free the apparatus of air in the line by use of the venting screw (14) and by manual compression of the transparent
flexible tube that connects the pump to the fluid reservoir.
10.4.4 Set the stroke counter so that the pump will run a sufficient length of time to evacuate the fluid out of the fluid reservoir.
10.4.5 Start the pump. Observe the fluid level in the reservoir and stop the pump when all the fluid is out of the base of the
reservoir but is still fully-retained in line (10).
10.4.6 Add a minimum of 50 mL of RL233 fluid to the fluid reservoir a second time and operate the pump until the fluid
reservoir is empty but line (10) is still filled with fluid.
10.4.7 After all oil has drained, close the stopcock on the atomization chamber drain line (19), position stopcock (6) so that fluid
will flow from the cooling jacket into the fluid reservoir.
10.4.8 Remove the thermometer or temperature probe from the fluid reservoir.
NOTE 12—The thermometer and assembly can interfere with the obtainment of accurate volume measurements in the fluid reservoir, hence its removal
is called for when the accurate determination of fluid volume is needed. A thermocouple or thermistor probe is a suitable alternative to a thermometer.
10.4.9 Add a minimum amount of fluid equal to the sum of 30 mL plus V , determined in 10.2.8, to the fluid reservoir.
run
10.4.10 Close the stopcock below the atomization chamber drain line (19) and position stopcock (6) so that the fluid will drain
from the cooling jacket into the fluid reservoir.
NOTE 13—The atomization chamber drain line is always closed for the third cleaning run and all test runs.
10.4.11 Free the apparatus of air in the line by manual compression of the flexible tube (10) that conn
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