ASTM G63-99(2007)
(Guide)Standard Guide for Evaluating Nonmetallic Materials for Oxygen Service
Standard Guide for Evaluating Nonmetallic Materials for Oxygen Service
SIGNIFICANCE AND USE
The purpose of this guide is to furnish qualified technical personnel with pertinent information for use in selecting materials for oxygen service in order to minimize the probability of ignition and the risk of explosion or fire. It is not intended as a specification for approving materials for oxygen service.
SCOPE
1.1 This guide applies to nonmetallic materials, (hereinafter called materials) under consideration for oxygen or oxygen-enriched fluid service, direct or indirect, as defined below. It is intended for use in selecting materials for applications in connection with the production, storage, transportation, distribution, or use of oxygen. It is concerned primarily with the properties of a material associated with its relative susceptibility to ignition and propagation of combustion; it does not involve mechanical properties, potential toxicity, outgassing, reactions between various materials in the system, functional reliability, or performance characteristics such as aging, shredding, or sloughing of particles, except when these might contribute to an ignition.
1.2 When this document was originally published in 1980, it addressed both metals and nonmetals. Its scope has been narrowed to address only nonmetals and a separate standard Guide G 94 has been developed to address metals.
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 and health practices and determine the applicability of regulatory limitations prior to use.
Note 1—The American Society for Testing and Materials takes no position respecting the validity of any evaluation methods asserted in connection with any item mentioned in this guide. Users of this guide are expressly advised that determination of the validity of any such evaluation methods and data and the risk of use of such evaluation methods and data are entirely their own responsibility.
Note 2—In evaluating materials, any mixture with oxygen exceeding atmospheric concentration at pressures higher than atmospheric should be evaluated from the hazard point of view for possible significant increase in material combustibility.
General Information
Relations
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: G63 − 99 (Reapproved2007)
Standard Guide for
Evaluating Nonmetallic Materials for Oxygen Service
ThisstandardisissuedunderthefixeddesignationG63;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginal
adoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscript
epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope 2. Referenced Documents
1.1 This guide applies to nonmetallic materials, (hereinafter 2.1 ASTM Standards:
called materials) under consideration for oxygen or oxygen- D217Test Methods for Cone Penetration of Lubricating
enriched fluid service, direct or indirect, as defined below. It is Grease
intended for use in selecting materials for applications in D566TestMethodforDroppingPointofLubricatingGrease
connection with the production, storage, transportation, D1264Test Method for Determining the Water Washout
distribution, or use of oxygen. It is concerned primarily with Characteristics of Lubricating Greases
the properties of a material associated with its relative suscep- D1743Test Method for Determining Corrosion Preventive
tibility to ignition and propagation of combustion; it does not Properties of Lubricating Greases
involve mechanical properties, potential toxicity, outgassing, D1748Test Method for Rust Protection by Metal Preserva-
reactions between various materials in the system, functional tives in the Humidity Cabinet
reliability, or performance characteristics such as aging, D2512Test Method for Compatibility of Materials with
shredding, or sloughing of particles, except when these might Liquid Oxygen (Impact Sensitivity Threshold and Pass-
contribute to an ignition. Fail Techniques)
D2863Test Method for Measuring the Minimum Oxygen
1.2 Whenthisdocumentwasoriginallypublishedin1980,it
Concentration to Support Candle-Like Combustion of
addressed both metals and nonmetals. Its scope has been
Plastics (Oxygen Index)
narrowed to address only nonmetals and a separate standard
D4809Test Method for Heat of Combustion of Liquid
Guide G94 has been developed to address metals.
Hydrocarbon Fuels by Bomb Calorimeter (Precision
1.3 This standard does not purport to address all of the
Method)
safety concerns, if any, associated with its use. It is the
G72Test Method for Autogenous Ignition Temperature of
responsibility of the user of this standard to establish appro-
Liquids and Solids in a High-Pressure Oxygen-Enriched
priate safety and health practices and determine the applica-
Environment
bility of regulatory limitations prior to use.
G74Test Method for Ignition Sensitivity of Materials to
Gaseous Fluid Impact
NOTE 1—The American Society for Testing and Materials takes no
position respecting the validity of any evaluation methods asserted in
G86Test Method for Determining Ignition Sensitivity of
connection with any item mentioned in this guide. Users of this guide are
Materials to Mechanical Impact in Ambient Liquid Oxy-
expresslyadvisedthatdeterminationofthevalidityofanysuchevaluation
gen and Pressurized Liquid and Gaseous Oxygen Envi-
methods and data and the risk of use of such evaluation methods and data
ronments
are entirely their own responsibility.
NOTE 2—In evaluating materials, any mixture with oxygen exceeding G88Guide for Designing Systems for Oxygen Service
atmosphericconcentrationatpressureshigherthanatmosphericshouldbe
G93Practice for Cleaning Methods and Cleanliness Levels
evaluated from the hazard point of view for possible significant increase
for Material and Equipment Used in Oxygen-Enriched
in material combustibility.
Environments
G94Guide for Evaluating Metals for Oxygen Service
ThisguideisunderthejurisdictionofASTMCommitteeG04onCompatibility
and Sensitivity of Materials in Oxygen Enriched Atmospheres and is the direct
responsibility of Subcommittee G04.02 on Recommended Practices. For referenced ASTM standards, visit the ASTM website, www.astm.org, or
Current edition approved March 15, 2007. Published May 2007. Originally contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
approved in 1980. Last previous edition approved in 1999 as G63–99. DOI: Standards volume information, refer to the standard’s Document Summary page on
10.1520/G0063-99R07. the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
G63 − 99 (2007)
2.2 Federal Standard: experience, know how to apply physical and chemical prin-
Fed.TestMethodStd.91BCorrosionProtectionbyCoating: ciples involved in the reactions between oxygen and other
Salt Spray (Fog) Test materials.
2.3 Other Standard:
3.2.11 reactioneffect—thepersonnelinjury,facilitydamage,
BS 3N:100: 1985Specification for General Design Require-
productloss,downtime,ormissionlossthatcouldoccurasthe
ments for Aircraft Oxygen Systems and Equipment
result of an ignition.
2.4 Other Documents:
CGA Pamphlet G4.4Industrial Practices for Gaseous Oxy- 4. Significance and Use
gen Transmission and Distribution Piping System
4.1 The purpose of this guide is to furnish qualified techni-
NSS 1740.15NASA Safety Standard for Oxygen and Oxy-
cal personnel with pertinent information for use in selecting
gen Systems
materialsforoxygenserviceinordertominimizetheprobabil-
ityofignitionandtheriskofexplosionorfire.Itisnotintended
3. Terminology
as a specification for approving materials for oxygen service.
3.1 Definitions:
3.1.1 autoignition temperature—the temperature at which a
5. Factors Affecting Selection of Material
materialwillspontaneouslyigniteinoxygenunderspecifictest
5.1 General—The selection of a material for use with
conditions (see Guide G88).
oxygen or oxygen-enriched atmospheres is primarily a matter
3.2 Definitions of Terms Specific to This Standard:
of understanding the circumstances that cause oxygen to react
3.2.1 direct oxygen service—in contact with oxygen during
with the material. Most materials in contact with oxygen will
normaloperations.Examples:oxygencompressorpistonrings,
not ignite without a source of ignition energy. When an
control valve seats.
energy-input rate, as converted to heat, is greater than the rate
of heat dissipation, and the temperature increase is continued
3.2.2 impact-ignition resistance—the resistance of a mate-
for sufficient time, ignition and combustion will occur. Thus
rial to ignition when struck by an object in an oxygen
considered: the material’s minimum ignition temperature, and
atmosphere under a specific test procedure.
the energy sources that will produce a sufficient increase in the
3.2.3 indirect oxygen service—not normally in contact with
temperature of the material. These should be viewed in the
oxygen, but which might be as a result of a reasonably
context of the entire system design so that the specific factors
foreseeablemalfunction,operatorerror,orprocessdisturbance.
listed below will assume the proper relative significance. To
Examples: liquid oxygen tank insulation, liquid oxygen pump
summarize: it depends on the application.
motor bearings.
5.2 Properties of the Material:
3.2.4 maximum use pressure—the maximum pressure to
5.2.1 Factors Affecting Ease of Ignition—Generally, in con-
which a material can be subjected due to a reasonably
sideringamaterialforaspecificoxygenapplication,oneofthe
foreseeable malfunction, operator error, or process upset.
most significant factors is its minimum ignition temperature in
3.2.5 maximum use temperature—the maximum tempera-
oxygen. Other factors that will affect its ignition are relative
ture to which a material can be subjected due to a reasonably
resistance to impact, geometry, configuration, specific heat,
foreseeable malfunction, operator error, or process upset.
relative porosity, thermal conductivity, preoxidation or
3.2.6 nonmetallic—any material, other than a metal, or any
passivity, and “heat-sink effect.” The latter is the heat-transfer
composite in which the metal is not the most easily ignited
aspect of the material to the mass in intimate contact with it,
componentandforwhichtheindividualconstituentscannotbe
with respect to both the amount and the physical arrangement
evaluated independently.
of each and to their respective physical properties. For
instance, a gasket material may have a relatively low ignition
3.2.7 operating pressure—the pressure expected under nor-
temperature but be extremely resistant to ignition when con-
mal operating conditions.
fined between two steel flanges. The presence of a small
3.2.8 operating temperature—the temperature expected un-
amount of an easily ignitable material, such as a hydrocarbon
der normal operating conditions.
oil or a grease film, can promote the ignition of the base
3.2.9 oxygen-enriched—appliestoafluid(gasorliquid)that
material.Accordingly, cleanliness is vital to minimize the risk
contains more than 25 mol % oxygen. 7
of ignition (1). See also Practice G93 and Refs. 2–3.
3.2.10 qualified technical personnel—persons such as engi-
5.2.2 Factors Affecting Propagation—After a material is
neers and chemists who, by virtue of education, training, or
ignited, combustion may be sustained or may halt.Among the
factors that affect whether fire will continue are the basic
composition of the material, the pressure, initial temperature,
AvailablefromU.S.GovernmentPrintingOfficeSuperintendentofDocuments,
the geometric state of the matter, and whether the available
732 N. Capitol St., NW, Mail Stop: SDE, Washington, DC 20401, http://
www.access.gpo.gov. oxygen will be consumed or the accumulation of combustion
Available from British Standards Institute (BSI), 389 Chiswick High Rd.,
products reduce the availability of oxygen sufficiently to stop
London W4 4AL, U.K., http://www.bsi-global.com.
Available from Compressed Gas Association (CGA), 4221 Walney Rd., 5th
Floor, Chantilly, VA 20151-2923, http://www.cganet.com.
6 7
National Aeronautics and Space Administration, Office of Safety and Mission Theboldfacenumbersinparenthesesrefertothelistofreferencesattheendof
Assurance, Washington, DC. this standard.
G63 − 99 (2007)
the reaction. Combustion may also be interrupted by the also decrease; therefore, greater latitude may be exercised in
presence of a heat sink. the selection of materials.
5.2.3 Properties and Conditions Affecting Potential Resul-
5.4 Ignition Mechanisms—For an ignition to occur, it is
tant Damage—A material’s heat of combustion, its mass, the
necessary to have three elements present: oxidizer, fuel, and
oxygen concentration, flow conditions before and after
ignition energy. The oxygen environment is obviously the
ignition, and the flame propagation characteristics affect the
oxidizer, and the material under consideration is the fuel.
potential damage if ignition should occur and should be taken
Several potential sources of ignition energy are listed below.
into account in estimating the reaction effect in 7.5.
The list is neither all-inclusive nor in order of importance nor
5.3 Operating Conditions—Conditions that affect the suit- in frequency of occurrence.
ability of a material include the other materials of construction 5.4.1 Friction—Therubbingoftwosolidmaterialsresultsin
and their arrangement in the equipment and pressure, the generation of heat. Example: the rub of a centrifugal
temperature, concentration, flow, and velocity of the oxygen. compressor rotor against its casing.
Pressure and temperature are generally the most significant, 5.4.2 Heat of Compression—Heat is generated from the
conversion of mechanical energy when a gas is compressed
and their effects show up in the estimate of ignition potential
(5.4) and reaction effect (5.5), as explained in Section 7. from a low to a high pressure. This can occur when high-
5.3.1 Pressure—Thepressureisimportant,notonlybecause pressure oxygen is released into a dead-ended tube or pipe,
it generally affects the generation of potential ignition quickly compressing the residual oxygen that was in the tube
mechanisms, but also because it usually significantly affects ahead of it. Example: a downstream valve in a dead-ended
the destructive effects if ignition should occur. While general- high-pressure oxygen manifold.
izations are difficult, rough scales would be as given in Table 5.4.2.1 Equation—An equation that can be used to estimate
1. the theoretical maximum temperature that can be developed
when pressurizing oxygen rapidly from one pressure and
NOTE 3—While the pressure generally affects the reaction as indicated
temperature to an elevated pressure is as follows:
in Table 1, tests indicate that it has varying effects on individual
flammability properties. For example, for many materials, increasing ~n21!/n
T /T 5 @P /P # (1)
f i f i
pressure results in the following:
(1)An increase in propagation rate, with the greatest increase in rate at
where:
lower pressures but with significant increases in rate at high pressures;
T = final temperature, abs,
f
(2) A reduction in ignition temperature, with the greatest decrease at
T = initial temperature, abs,
i
low pressure and a smaller rate at high pressure, however, it should be
P = final pressure, abs,
noted that increasing autoignition temperatures with increasing pressures f
P = initial pressure, abs, and
have been reported for selected polymers, due to competing kinetics (4);
i
C
(3) An increase in sensitivity to mechanical impact; n =
p
51.40 for oxygen,
(4) A reduction in oxygen index, as measured in an exploratory study C
v
(5), with sharper initial declines in materials of high oxygen index but
where:
with only slight relative declines in general above 10 atmospheres and up
C = specific heat at constant pressure, and
to at least 20 atmospheres;
p
(5) A negligible change in heat of combustion; and C = specific heat at constant volume.
v
(6)Anincreaseinthelikelihoodofadiabaticcompressionignition,with
Table 2 gives the theoretical temperatures which could be
the greatest likelihood at the highest pressures.
obtained by compressing oxygen from one atmosphere (abso-
In the case of friction, increased pressure may improve heat
lute) and 20°C to the pressures shown.
dissipation and make ignition at constant frictional energy
inputlesslikelythanatlowerpressure.Increasedpressurealso
reduces the likelihood of spark generation at constant electric
TABLE 2 Theoretical Maximum Temperature Obtained When
field strength through increased breakdown voltage values.
Compressing Oxygen Adiabatically from 20°C and One Standard
5.3.2 Temperature—Increasing temperature obviously in-
A
Atmosphere to the Pressures Shown
creases the risk of ignition but does not generally contribute to
Final Pressure, P Final Temperature, T
f Pressure Ratio f
the reaction effect.
...
Questions, Comments and Discussion
Ask us and Technical Secretary will try to provide an answer. You can facilitate discussion about the standard in here.