ASTM D3429-93(2012)
(Test Method)Standard Test Method for Solubility of Fixed Gases in Low-Boiling Liquids (Withdrawn 2017)
Standard Test Method for Solubility of Fixed Gases in Low-Boiling Liquids (Withdrawn 2017)
SIGNIFICANCE AND USE
The solubility of fixed gases in liquids is an important engineering parameter in the design of hydraulic systems. It is a measure of the amount of gas that can be released from solution when a system undergoes changes in pressure and temperature. Theoretical considerations permit approximate values of gas solubility to be computed with reasonable accuracy. Dissolved gases are separated and quantified chromatographically. The test method is restricted to use with low-boiling liquid samples.
SCOPE
1.1 This test method covers the determination of the solubilities of nonreactive gases such as nitrogen and helium in liquids that boil below 273 K. This test method is applicable at temperatures from 77 to 300 K from subambient pressure to 6.5 MPa (65 atm). This test method does not provide for analysis of the vapor phase in equilibrium with the liquid (see Section 3 for a description of terms).
1.2 This test method as written describes the procedures to be followed for determination of the solubilities of helium and nitrogen. If suitable modifications are made to the analytical measurements by gas chromatography, solubilities of other gases such as argon, hydrogen, oxygen, etc., can be determined.
1.3 The values stated in SI units are to be regarded as the standard. In cases where materials, products, or equipment are available in inch-pound units only, SI units are omitted.
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. For specific hazard statements, see 6.1.2 and 7.1 and Annex A1.
WITHDRAWN RATIONALE
This test method covered the determination of the solubilities of nonreactive gases such as nitrogen and helium in liquids that boil below 273 K. This test method was applicable at temperatures from 77 K to 300 K from subambient pressure to 6.5 MPa (65 atm). This test method did not provide for analysis of the vapor phase in equilibrium with the liquid.
Formerly under the jurisdiction of Committee D02 on Petroleum Products, Liquid Fuels, and Lubricants, this test method was withdrawn in December 2017. This standard is being withdrawn without replacement due to its limited use by industry.
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Standards Content (Sample)
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: D3429 − 93 (Reapproved 2012)
Standard Test Method for
Solubility of Fixed Gases in Low-Boiling Liquids
This standard is issued under the fixed designation D3429; 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.
1. Scope 3.1.1 carrier gas, n—gasusedtosweepsamplesthroughthe
gas chromatograph.
1.1 This test method covers the determination of the solu-
3.1.2 elution, n—the process of removing a material ab-
bilities of nonreactive gases such as nitrogen and helium in
sorbed on the stationary phase of the gas chromatograph
liquidsthatboilbelow273K.Thistestmethodisapplicableat
column by displacing it with the flowing carrier gas.
temperatures from 77 to 300 K from subambient pressure to
6.5 MPa (65 atm). This test method does not provide for
3.1.3 fractionation, n—change of composition caused by
analysis of the vapor phase in equilibrium with the liquid (see
change of pressure.
Section 3 for a description of terms).
3.1.4 liquid or test liquid, n—solvent for test gas.
1.2 This test method as written describes the procedures to
3.1.5 nonreactive gas, n—gasthatdoesnotreactchemically
be followed for determination of the solubilities of helium and
with the test liquid.
nitrogen. If suitable modifications are made to the analytical
3.1.6 test gas, n—gas whose solubility is being determined.
measurements by gas chromatography, solubilities of other
3.1.7 vapor, n—vapor phase of test liquid.
gases such as argon, hydrogen, oxygen, etc., can be deter-
mined.
4. Summary of Test Method
1.3 The values stated in SI units are to be regarded as the
4.1 Asample of test liquid A is saturated with test gas B at
standard. In cases where materials, products, or equipment are
specified temperature and pressure.Aportion of the solution is
available in inch-pound units only, SI units are omitted.
withdrawn and vaporized in an evacuated sample container at
1.4 This standard does not purport to address all of the
room temperature.The concentration of gas B in the vaporized
safety concerns, if any, associated with its use. It is the
sample is determined by gas chromatography. It is necessary
responsibility of the user of this standard to establish appro-
that the molar concentration of the gas in the sample container
priate safety and health practices and determine the applica-
be the same as in the liquid phase. This will be true if
bility of regulatory limitations prior to use. For specific hazard
fractionation of the sample is avoided while withdrawing it
statements, see 6.1.2 and 7.1 and Annex A1.
from the liquid phase, if no decomposition or polymerization
ofthetestliquidoccursonvaporization,andifthevaporofthe
2. Referenced Documents
testliquiddoesnotreactwiththewallsofthesamplecontainer
2.1 ASTM Standards:
or connecting lines. It is also necessary that both the test gas
E260Practice for Packed Column Gas Chromatography
andthevaporofthetestliquidbehavenearlyideallyat101kPa
(1atm).Iftheaboverequirementsaremet,thistestmethodwill
3. Terminology
give estimates of solubility with an accuracy of 62%.
3.1 Definitions of Terms Specific to This Standard:
5. Significance and Use
5.1 The solubility of fixed gases in liquids is an important
This test method is under the jurisdiction of ASTM Committee D02 on
Petroleum Products, Liquid Fuels, and Lubricants and is the direct responsibility of engineering parameter in the design of hydraulic systems. It is
SubcommitteeD02.L0.07onEngineeringSciencesofHighPerformanceFluidsand
a measure of the amount of gas that can be released from
Solids (Formally D02.1100).
solution when a system undergoes changes in pressure and
Current edition approved April 15, 2012. Published April 2012. Originally
temperature. Theoretical considerations permit approximate
approved in 1975. Last previous edition approved in 2007 as D3429–93(2007).
DOI: 10.1520/D3429-93R12.
values of gas solubility to be computed with reasonable
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
accuracy. Dissolved gases are separated and quantified chro-
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
matographically. The test method is restricted to use with
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website. low-boiling liquid samples.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D3429 − 93 (2012)
6. Apparatus 6.1.2 Nitrogen Vapor Cryostat, with suitable temperature
measurement and control devices, to provide the low-
6.1 Saturator and Sampler System, suitable for the tests of
temperature environment for the high-pressure test chamber.
low-boiling liquids and gases at various pressures and
The cryostat consists of a cylindrical stainless steel Dewar or
temperatures, shown schematically in Fig. 1. The system
other suitable insulated container not less than 0.3 m in inside
comprises four parts:
diameter and approximately 0.5 m in inside depth.Asolenoid
6.1.1 High-Pressure Test Chamber,withinternalcapacityof
valveisusedtoadmitliquidnitrogentothecryostat.Theliquid
approximately(1L)suchasshowninFig.2.Thelidofthetest
nitrogencoolsthecryostatanditscontents.Theliquidnitrogen
chamber is equipped with three ports. The first is to contain a
(Warning—See 7.1.) should be introduced through a diffuser,
thermocouple well, the second is for the addition of the test
or in a fine stream behind a sheet metal baffle, so that liquid
liquid and pressurization of the system with the test gas, and
does not impinge directly on the test chamber or the controller
the third port is for withdrawal of the sample of solution from
thermocouple.Thelattermaybeattachedlooselytothesideof
the liquid phase by means of an eductor tube which extends to
thetestchamberforconvenience,butgoodthermalcouplingto
the bottom of the chamber. The high-pressure assembly is
the chamber must not be made. Although the nitrogen vapor
mountedsothatanoscillatingmotioninahorizontalplanecan
cryostat can undergo temperature excursions of several
be applied to it mechanically with a frequency of 1 Hz (one
degrees, the test chamber will stabilize at a temperature that
cyclepersecond)andanamplitudeof0.02m.Loops(pigtails)
varies by only a few tenths of a degree because of its thermal
are formed in the connecting metal lines to the test chamber to
avoid undue stress. inertia.Tominimizeheattransferfromoutsideoftheapparatus
and frost condensation, the top of the cryostat should be
6.1.1.1 An electric motor geared down to provide a shaft
speed of about 60 rpm is convenient for providing the loosely covered with a lid of foamed glass or plastic, or other
necessary agitation. An eccentric or connecting rod from the similar insulating material. (Warning—Extremely cold. Lib-
motor shaft to the support rod imparts an oscillating motion. erates gas that can cause suffocation. Contact with skin causes
Withoutagitationanexcessivetimeisrequiredforequilibrium burns or freezing, or both. Vapors can react violently with hot
to be established. magnesium or aluminum alloys. See A1.1.)
NOTE 1—All lines and fittings 300 series stainless steel.
1. VI through V8—Stainless steel valves, metal-to-metal seat, bellows in the middle half of the scale, balance ± 3 % or better), com-
sealed 14 MPa (2000 psi) rating (V8 modified, see Fig. 3) pound range from 0 to 30 in. Hg and a gage pressure from 0 to
2. T/C-1—Copper-constantan thermocouple, test liquid temperature. 103 kPa (0 to 15 psi).
3. T/C-2—Copper-constantan thermocouple, vapor cryostat temperature con- 6. Burst Disk—Select to release at 50 % higher than maximum desired system
troller. pressure
4. G-1—Bourdon gage, 4 ⁄2 or 6-in. size, Grade 3A (accuracy ±0.25 % of 7. Temperature Controller —Range 77 to 300 K, accuracy ±0.5 % full range
maximum reading), range 1.5 times highest desired system pressure. 8. L—Loops in stainless steel lines for flexibility.
5. G-2—Bourdon gage, 3 ⁄2 to 6-in. size, Grade A or B (accuracy 2 % or better 9. R1 and R2—Gas pressure regulators with pressure gage.
FIG. 1 Saturator Apparatus—Schematic
D3429 − 93 (2012)
NOTE 1—All material 300 series stainless except flange gasket. Design of perforated baffles not critical but leave 6-mm diameter holes spaced on
20-mm centers are recommended. Baffles should be spot-welded to the inside of the chamber to prevent movement. The purpose of the baffles is to
increase turbulence in the liquid and thereby increase the rate of solubility of gas in the test liquid.
NOTE 2—The conflat flange manufactured by the Varian Corp. of Palo Alto, CA, is suitable.
FIG. 2 Test Chamber Detail
6.1.3 Vacuum and Pressurization Manifold, required for amount of liquid lost through purging, the sample valve (V8 in
initial evacuation of the test chamber, filling the chamber with Fig. 1) should be modified to reduce liquid holdup to a
the test liquid, and pressurizing the chamber with the test gas minimum.The details of this modification are shown in Fig. 3.
to the desired total pressure.The manifold is shown on the left
6.2 Gas Chromatograph, required for determination of the
side of Fig. 1.
gasconcentrationinthesample.Itmustbeequippedwithagas
6.1.3.1 The burst disk shown in Fig. 1 shall be of the type
sampling valve. It is desirable that two different size loops be
capable of withstanding an external pressure of 101 kPa (1
provided so that the sample size can be adjusted depending on
atm) when the system is evacuated.
theconcentrationoftestgastobedetermined.Sampleloopsof
6.1.3.2 The pump used to evacuate the apparatus shall be a
0.5 and 2.0 mL are recommended. The gas chromatograph
good quality oil-filled mechanical pump capable of producing
system must permit easy and rapid change of carrier gas and
−6
an ultimate vacuum of 0.1 Pa (10 atm) or better. If condens-
columns to suit a wide variety of analytical requirements. A
able vapors or reactive vapors are to be pumped, the pump
thermal conductivity detector of the glass-coated bead type is
shallbeprotectedbyasuitableabsorberorcoldtrap.Thepump
recommended. The instrumentation should provide a variable
shall run continuously for the duration of the test.
attenuator for the detector signal so that a wide range of fixed
6.1.4 Solution-Sampling System—This system utilizes a
gas concentrations may be accommodated. A suitable chart
3-mm ( ⁄8-in.) outside diameter heavy-wall stainless steel
recorder, preferably equipped with integrator, should be pro-
eductor tube extending nearly to the bottom of the test
vided. Alternatively, a digital readout may be used. A typical
chamber. The eductor tube end extending outside the chamber
gas chromatograph is shown schematically in Fig. 4, and its
is connected to a valve just above the top of the cryostat, and
power supply is shown in Fig. 5.
the outlet of this valve leads to a sample cylinder or container
NOTE 1—Practice E260 provides further description.
of about 100-mL volume. Each time a sample is withdrawn
from the liquid phase, the eductor tube and sampling valve 6.3 Leak Testing—All parts of the system should be tested
must be purged, otherwise the liquid and vapor in the line will with helium for leakage at a pressure 1.5 times test operating
not necessarily be of equilibrium composition. To reduce the pressure and vacuum leak tested. The test should include
D3429 − 93 (2012)
NOTE 1—Stainless steel wire extends from the position shown in the valve to the lower end of the eductor tube. The purpose of this modification is
to reduce the volume of the valve upstream of the poppet to minimum. A valve with a blunt poppet, rather than a needle, is preferred for this service.
FIG. 3 Sampling Valve (V8) Modification
FIG. 4 Gas Chromatograph Schematic
externalleaksandport-to-portleaksinvalves.Thetotalsystem absolutemolefractionoftheheliumconcentration.Nitrogenis
maximum acceptable leak rate is 0.1 std cm atm/s. A mass used as the carrier gas when helium is the gas whose solubility
spectrometer leak detector is suitable for the leak rate mea-
is to be determined. Helium is used as the carrier gas when
surements.
nitrogen solubility is being determined. (Warning—
Compressed gas under high pressure. Gas reduces oxygen
7. Reagents and Materials
available for breathing. See A1.2.)
7.1 Calibration Mixtures—Gas Chromatography—For the
7.2 Column Materials—Because only two-component sys-
determination of nitrogen solubility, one or more mixtures of
tems are analyzed and the boiling points of the test gas and
nitrogen in helium are required for calibration of the gas
liquid are relatively far apart, a relatively short column is
chromatograph. Concentrations of 2% and 10% are recom-
sufficient to provide resolution. For most test liquids, a 0.2-m
mended. The exact concentration of each mixture must be
column of silica gel or molecular sieve will separate the test
accuratelyknownto 61%oftheabsoluteconcentrationofthe
gasandtestliquid.Thecolumnshouldbeconstructedof6-mm
minor constituent. Certified calibration mixtures are available
(0.25-in.) thin-walled stainless steel tubing. Certain reactive
from suppliers of commercial cylinder gases. For the determi-
test liquids, particularly the powerful oxidizers that contain
nation of helium solubilities, mixtures of helium in nitrogen
fluorine, may react with the stationary phase materials to
containing about 0.2% and 1.0% helium are recommended.
The exact concentration should be known to 61% of the produce interferences. If this is the case, more elaborate
D3429 − 93 (2012)
FIG. 5 Power Supply Schematic
columns must be used to afford resolution. Each combination 8. Safety Precautions
of gas and liquid poses its own particular analytical problem
8.1 This procedure is applicable to determination of solu-
and a certain amount of experimentation with stationary phase
bilities of gases in highly reactive or flammable test liquids at
materials may be required. Table 1 contains a list of materials
high pressure under cryogenic conditions. It is mandatory that
found appropriate for some typical test gas/liquid combina-
adequate safety precautions be employed.All parts of systems
tions.
at high pressure must be provided with suitable barricades to
7.3 Gases, Compressed—High-purity helium and nitrogen, prevent injury to operating personnel in the event of rupture of
or other test gases, are required for saturating the test liquids. the
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