ASTM D3829-93(1998)
(Test Method)Standard Test Method for Predicting the Borderline Pumping Temperature of Engine Oil
Standard Test Method for Predicting the Borderline Pumping Temperature of Engine Oil
SCOPE
1.1 This test method covers the prediction of the borderline pumping temperature (BPT) of engine oils through the use of a 16-h cooling cycle over the temperature range from 0 to -40°C.
1.2 Applicability to petroleum products other than engine oils has not been determined.
1.3 This test method uses the millipascal (mPa[dot]s), as the unit of viscosity. For information, the equivalent centipoise unit is shown in parentheses.
1.4 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.
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NOTICE: This standard has either been superseded and replaced by a new version or
withdrawn.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: D 3829 – 93 (Reapproved 1998) An American National Standard
AMERICAN SOCIETY FOR TESTING AND MATERIALS
100 Barr Harbor Dr., West Conshohocken, PA 19428
Reprinted from the Annual Book of ASTM Standards. Copyright ASTM
Standard Test Method for
Predicting the Borderline Pumping Temperature of
1
Engine Oil
This standard is issued under the fixed designation D 3829; 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.
2
1. Scope
2VR
s
G 5 (1)
r 2
~R – R !
1.1 This test method covers the prediction of the borderline
s2 r
pumping temperature (BPT) of engine oils through the use of 2
4pR
s
G 5 (2)
a 16-h cooling cycle over the temperature range from 0 r
2 2
t R – R !
~
s r
to −40°C.
1.2 Applicability to petroleum products other than engine where:
oils has not been determined. G 5 shear rate at the surface of the rotor in reciprocal
r
−1
1.3 This test method uses the millipascal (mPa·s), as the unit
seconds, s ,
V5 angular velocity, rad/s,
of viscosity. For information, the equivalent centipoise unit is
R 5 stator radius, mm,
shown in parentheses.
s
R 5 rotor radius, mm, and
1.4 This standard does not purport to address all of the r
t 5 time in seconds for one revolution of the rotor.
safety concerns, if any, associated with its use. It is the
For the specific apparatus being described in 5.1.1,
responsibility of the user of this standard to establish appro-
priate safety and health practices and determine the applica-
63
G 5 (3)
r
t
bility of regulatory limitations prior to use.
2.1.6 shear stress—the motivating force per unit area for
2. Terminology
fluid flow. Area is the area under shear. For the rotary
2.1 Definitions:
viscometer being described, the rotor surface is the area under
2.1.1 viscosity—the ratio between the applied shear stress
shear.
and rate of shear. It is sometimes called the coefficient of
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T 5 9.81M~R 1 R ! 3 10 (4)
r o t
dynamic viscosity. This value is thus a measure of the
T
resistance to flow of the liquid. The SI unit of viscosity is the
r
9
S 5 3 10 (5)
r 2
pascal second (Pa·s). The centipoise (cP) is one millipascal
2p R h
r
second (mPa·s) and is often used.
where:
2.1.2 Newtonian oil or fluid—an oil or fluid that at a given
T 5 torque applied to rotor, N·m,
r
temperature exhibits a constant viscosity at all shear rates or
M 5 applied mass, g,
shear stresses.
R 5 radius of the shaft, mm,
o
2.1.3 non-Newtonian oil or fluid—an oil or fluid that at a
R 5 radius of the thread, mm,
t
given temperature exhibits a viscosity that varies with chang-
S 5 shear stress at the rotor surface, Pa, and
r
ing shear stress or shear rate.
h 5 height of the rotor, mm.
2.1.4 apparent viscosity—the determined viscosity obtained
For the dimensions given in 5.1.1,
by use of this test method.
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T 5 31.7M 3 10 (6)
r
2.1.5 shear rate—the velocity gradient in fluid flow. For a
Newtonian fluid in a concentric cylinder rotary viscometer in S 5 3.5M (7)
r
which the shear stress is measured at the inner cylinder surface
2.2 Definitions of Terms Specific to This Standard:
(such as the apparatus being described), and ignoring any end
2.2.1 calibration oils—those oils for establishing the instru-
effects, the shear rate is given as follows:
ment’s reference framework of apparent viscosity versus speed
from which the apparent viscosities of test oils are determined.
Calibration oils, which are essentially Newtonian fluids, are
1
This test method is under the jurisdiction of ASTM Committee D-2 on
available commercially, and have an approximate viscosity of
Petroleum Products and Lubricants and is the direct responsibility of Subcommittee
2
30 000 mPa·s (30 000 cP) at −20°C.
D02.07 on Flow Properties.
2.2.2 test oil—any oil for which the apparent viscosity and
Current edition approved Sept. 15, 1993. Published November 1993. Originally
published as D 3829 – 79. Last previous edition D 3829 – 87.
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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.¬
D 3829
yield stress are to be determined by use of the test method 5.3 A means of lowering the temperature to the predeter-
under description. mined test temperature at a controlled, nonlinear rate.
2
2.2.3 yield stress—the shear stress required to initiate flow. 5.4 Circulating System, for supplying suitable liquid cool-
For all Newtonian fluids and some non-Newtonian fluids, yield ant to the block as needed. Methanol is a suitable coolant. One
stress is zero. Some engine oils have a yield stress that is
...
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