ASTM D5949-16(2022)

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.
Designation: D5949 − 16 (Reapproved 2022)
Standard Test Method for
Pour Point of Petroleum Products (Automatic Pressure
Pulsing Method)
This standard is issued under the fixed designation D5949; 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.
INTRODUCTION
This test method covers an alternative procedure for the determination of pour point of petroleum
products using an automatic apparatus.
1. Scope Development of International Standards, Guides and Recom-
mendations issued by the World Trade Organization Technical
1.1 This test method covers the determination of pour point
Barriers to Trade (TBT) Committee.
of petroleum products by an automatic instrument that applies
a controlled burst of nitrogen gas onto the specimen surface
2. Referenced Documents
while the specimen is being cooled and detects movement of
2.1 ASTM Standards:
the surface of the test specimen with an optical device.
D97Test Method for Pour Point of Petroleum Products
1.2 This test method is designed to cover the range of
D4057Practice for Manual Sampling of Petroleum and
temperatures from−57°C to+51°C. However, the range of
Petroleum Products
temperatures included in the 1992 interlaboratory test program
D4177Practice for Automatic Sampling of Petroleum and
only covered the temperature range from −39°C to+6°C and
Petroleum Products
the range of temperatures included in the 1998 interlaboratory
D6708Practice for StatisticalAssessment and Improvement
test program was from −51°C to −11°C. (see 13.4).
of Expected Agreement Between Two Test Methods that
1.3 Test results from this test method can be determined at
Purport to Measure the Same Property of a Material
1°C or 3°C testing intervals.
2.2 Energy Institute Standard:
IP15Test Method for Pour Point of Petroleum Products
1.4 This test method is not intended for use with crude oils.
NOTE 1—The applicability of this test method or residual fuel samples 3. Terminology
has not been verified. For further information on applicability, refer to
3.1 Definitions:
13.4.
3.1.1 pour point, n—in petroleum products, the lowest
1.5 The values stated in SI units are to be regarded as
temperature at which movement of the test specimen is
standard. No other units of measurement are included in this
observed under the prescribed conditions of the test.
standard.
3.2 Definitions of Terms Specific to This Standard:
1.6 This standard does not purport to address all of the
3.2.1 no-flow point, n—in petroleum products, the tempera-
safety concerns, if any, associated with its use. It is the
ture of the test specimen at which a wax crystal structure or
responsibility of the user of this standard to establish appro-
viscosity increase, or both, impedes movement of the surface
priate safety, health, and environmental practices and deter-
of the test specimen under the conditions of the test.
mine the applicability of regulatory limitations prior to use.
3.2.1.1 Discussion—The no-flow point occurs when, upon
1.7 This international standard was developed in accor-
cooling, the formation of wax crystal structures or viscosity
dance with internationally recognized principles on standard-
increase,orboth,hasprogressedtothepointwheretheapplied
ization established in the Decision on Principles for the
observation device no longer detects movement under the
1 2
This test method is under the jurisdiction of ASTM Committee D02 on For referenced ASTM standards, visit the ASTM website, www.astm.org, or
Petroleum Products, Liquid Fuels, and Lubricants and is the direct responsibility of contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
Subcommittee D02.07 on Flow Properties. Standards volume information, refer to the standard’s Document Summary page on
Current edition approved July 1, 2022. Published August 2022. Originally the ASTM website.
approved in 1996. Last previous edition approved in 2016 as D5949–16. DOI: Available from Energy Institute, 61 New Cavendish St., London, WIG 7AR,
10.1520/D5949-16R22. U.K., http://www.energyinst.org.uk.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D5949 − 16 (2022)
conditions of the test. The preceding observation temperature, 6. Apparatus
at which flow of the test specimen is last observed, is the pour 5
6.1 Automatic Apparatus —The automatic pour point appa-
point.
ratusdescribedinthistestmethodconsistsofamicroprocessor
3.2.2 pulse, n—a controlled burst of nitrogen gas of a fixed controlled test chamber that is capable of heating and cooling
the test specimen, providing a controlled pulse of compressed
pressure and flow rate sufficient to cause movement on the
surface of the test specimen without fracturing the wax gasontothespecimensurface,opticallydetectingthespecimen
surface movement, and recording the temperature of the
structure which may be formed in the specimen.
specimen as described in detail in AnnexA1. It is specifically
3.2.3 Peltier device, n—a solid-state thermoelectric device
designed to detect the lowest temperature at which movement
constructed with dissimilar semiconductor materials, config-
of the surface of the specimen is observed upon application of
ured in such a way that it will transport heat to or away from
the pulse.
a test specimen dependent on the direction of electric current
applied to the device. 6.2 Theapparatusshallbeequippedwithaspecimencup,an
array of optical detectors, light source, pressure pulsing unit,
digital display, Peltier device, and a specimen temperature
4. Summary of Test Method
measuring device.
4.1 Afterinsertingthetestspecimenintotheautomaticpour
6.3 The pressure pulsing unit consists of a stainless steel
point apparatus, and initiation of the test program, the test
tubing, 250mm 6 2mm long and 1.1mm 6 0.1mm inside
specimenisheatedandthencooledbyaPeltierdeviceatarate
diameter. This tubing is connected to a constant pressure
of 1.5°C⁄min 6 0.1°C⁄min.At temperature intervals of 1°C
sourceatoneend,whichservesasaninlet.Theotherendofthe
or3°C,dependingontheselectionmadebytheuser,amoving
tubing, which serves as the outlet, is bent and positioned such
force in the form of a pressurized pulse of compressed gas is
that it is pointing to the center of the specimen at an acute
imparted onto the surface of the specimen. Multiple optical
angle. The distance between the outlet and the center of the
detectorsareusedinconjunctionwithalightsourcetomonitor
specimen is 8mm 6 2mm.
movementofthesurfaceofthespecimen.Thelowesttempera-
ture at which movement of the specimen surface is observed
6.4 ThePeltierdeviceshallbecapableofheatingorcooling
upon application of a pulse of compressed gas is recorded as
the test specimen at a rate of 1.5°C⁄min 6 0.1°C⁄min.
the pour point, Test Method D5949.
6.5 The temperature measuring device in the specimen cup
shall be capable of measuring the temperature of the test
5. Significance and Use
specimen from−80°C to+70°C at a resolution of 0.1°C.
5.1 Thepourpointofapetroleumproductisanindexofthe
6.6 The apparatus, if required, shall be equipped with
lowest temperature of its utility for certain applications. Flow
fittingstopermitthecirculationofwaterorotherliquidcooling
characteristics, like pour point, can be critical for the correct
mediatoremoveheatgeneratedbythePeltierdeviceandother
operation of lubricating oil systems, fuel systems, and pipeline
electronic components of the apparatus. Newer models have
operations.
internal sources of liquid cooling media and do not require
such fittings.
5.2 Petroleum blending operations require precise measure-
ment of the pour point.
6.7 The apparatus shall be equipped with fittings to permit
thedeliveryofnitrogengastothepressurepulsingunit.Newer
5.3 In most cases, this test method does not require the use
models have internal sources of compressed gas and do not
of mechanical refrigeration apparatus (see 7.1).
require such fittings.
5.4 This test method yields a pour point in a format similar
6.8 Ultrasonic Bath, Unheated—(optional)—with an oper-
to Test Method D97/IP15 when the 3°C interval results are
atingfrequencybetween25kHzto60kHzandatypicalpower
reported.
output of ≤100 W, of suitable dimensions to hold container(s)
NOTE 2—Since some users may wish to report their results in a format
similartoTestMethodD97(in3°Cintervals)theprecisionswerederived
from the temperatures rounded to the 3° intervals. For statements on bias
The following instrument has been found suitable for use in this test method:
relative to Test Method D97, see 13.3.
Phase Technology Pour Point Analyzer model series 30, 50, 70, 70V and 70X;
5.5 Test results from this test method can be determined at available from Phase Technology, 11168 Hammersmith Gate, Richmond, B.C.
CanadaV7A5H8.Inthe1998researchreport,the70Vwasreferredtoasthecurrent
either 1°C or 3°C intervals.
model; whereas models 30, 50, and 70 were referred to as pre-1998 models. The
various model series mentioned above are differentiated by their cooling capacities
5.6 This test method has better repeatability and reproduc-
and user interfaces; however, all of them are capable of covering the entire
ibility relative to Test Method D97/IP15 as measured in the
temperature range specified in the scope.
1992 and 1998 interlaboratory test programs.
Model series 30, 50, 70, and 70V require external sources of coolant and
compressed gas (dry nitrogen). Model series 70X has built-in internal sources of
coolant and compressed gas.
This pour point analyzer is covered by a patent. Interested parties are invited to
The results of this interlaboratory test program are available from ASTM submitinformationregardingtheidentificationofanalternativetothispatenteditem
International Headquarters in the form of a research report. Request RR:D02-1312 to the ASTM International Headquarters. Your comments will receive careful
for the 1992 program and RR:D02-1499 for the 1998 program. Contact ASTM consideration at a meeting of the responsible technical committee which you may
Customer Service at service@astm.org. attend.
D5949 − 16 (2022)
placed inside of bath, for use in effectively dissipating and 10. Calibration and Standardization
removing air or gas bubbles that can be entrained in viscous
10.1 Ensure that all of the manufacturer’s instructions for
sample types prior to analysis. It is permissible to use ultra-
calibrating, checking, and operating the apparatus are fol-
sonic baths with operating frequencies and power outputs
lowed.
outside this range, however it is the responsibility of the
10.2 A sample with a well-documented pour point can be
laboratory to conduct a data comparison study to confirm that
used to verify performance of the apparatus. Alternatively, a
results determined with and without the use of such ultrasonic
sample which has been extensively tested in a pour point
baths does not materially impact results.
interlaboratory study can be used.
7. Reagents and Materials
11. Procedure
7.1 Coolant—Tap water or other liquid heat exchange me-
11.1 Inspect the specimen cup to ensure that it is clean and
dium sufficient to remove heat generated by the Peltier device
dry. If needed, clean the cup in accordance with 11.3.
and other electronic components from the apparatus. To
11.2 Deliver 0.150mL 6 0.005 mL of specimen into the
achieve specimen cooling to−60°C, supply circulation of
specimen cup. Pipettes, syringes, or precision positive-
liquid cooling medium at+25°C or lower, if required, to the
displacement devices are suitable for use in delivering the
apparatus.Obtaincoolingperformancedatafromtheapparatus
specimen.Sampleswithanexpectedpourpointabove36°Cor
manufacturer if lower specimen temperatures are desired or if
which appear solid at room temperature may be heated above
the tap water temperature is higher than 25°C.
45°C, but shall not be heated above 70°C (see Note 4).
7.2 Dry Nitrogen Gas—Nitrogen gas with a dew point
11.3 Clean the specimen out of the cup. The cup shall be
below the lowest temperature attained by the specimen.
cleaned to the point where no visible droplets of specimen
(Warning—Compressed gas.)(Warning—Inert gas can be an
5 remain in the cup. Non-abrasive absorbent materials, such as
asphyxiant when inhaled.) Newer models have internal
cottonswabs,aresuitableforuseincleaningthespecimencup.
sources of compressed gas and do not require external dry
Cleaning solvents able to clean the specimen and compatible
nitrogen gas.
with the components of the apparatus may also be used.
7.3 Precision Volume-Dispensing Device, capable of dis-
Naphtha,hexane,andheptanearesuitableascleaningsolvents.
pensing 0.150mL 6 0.005 mL of sample.
11.4 Repeat steps 11.2 and 11.3.
7.4 Cotton Swab, plastic shaft cotton swabs to clean the
11.5 Carefully measure 0.150mL 6 0.005 mL of the
sample cup.
specimen into the specimen cup.
8. Sampling
11.6 Close and lock the test chamber lid.
8.1 Obtain a sample in accordance with Practice D4057 or
11.7 Follow the manufacturer’s instructions for preheating
by Practice D4177.
the specimen.
8.2 Samples of very viscous materials may be warmed until 11.8 Select the desired pour point testing interval: 1°C or
they are reasonably fluid before they are transferred; however, 3°C.
no sample shall be heated more than is absolutely necessary.
11.9 Start the test program following the manufacturer’s
The sample shall not be heated and transferred into the test
instructions.Thespecimenisfirstheatedasspecifiedin11.7.It
specimen cup unless its temperature is 70°C or lower.
is then cooled by the Peltier device at a rate of 1.5°C⁄min 6
0.1°C⁄min. The apparatus will apply a pulse of compressed
NOTE 3—In the event the sample has been heated above this
temperature,allowthesampletocooluntilitstemperatureisatleast70°C gas onto the specimen surface every 1°C or 3°C drop in
before transferring.
temperaturedependingonthetestingintervalspecifiedin11.8.
The specimen is illuminated by the light source, and the
8.3 Forsomesampletypes,suchasviscouslubeoilsthatare
prone to having entrained air or gas bubbles present in the movement of the specimen surface upon application of a pulse
is monitored by an array of optical detectors. The test will
sample, the use of an ultrasonic bath (see 6.8) without the
heater turned on (if so equipped), has been found effective in continue until application of
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