ASTM G86-17

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: G86 − 17
Standard Test Method for
Determining Ignition Sensitivity of Materials to Mechanical
Impact in Ambient Liquid Oxygen and Pressurized Liquid
and Gaseous Oxygen Environments
ThisstandardisissuedunderthefixeddesignationG86;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginal
adoption or, in the case of revision, the year of last revision.Anumber in parentheses indicates the year of last reapproval.Asuperscript
epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope Development of International Standards, Guides and Recom-
mendations issued by the World Trade Organization Technical
1.1 This test method describes test equipment and tech-
Barriers to Trade (TBT) Committee.
niques to determine the impact sensitivity of materials in
oxygen under two different conditions: (1) in ambient pressure
2. Referenced Documents
liquid oxygen (LOX) or (2) under pressure-controlled condi-
tions in LOX or gaseous oxygen (GOX). It is applicable to
2.1 ASTM Standards:
materials for use in LOX or GOX systems at pressures from
D1193 Specification for Reagent Water
ambient to 68.9 MPa (0 to 10 000 psig). The test method
D4080 Specification for Trichloroethylene, Technical and
described herein addresses testing with pure oxygen environ-
Vapor-Degreasing Grade
ments; however, other oxygen-enriched fluids may be substi-
G63 Guide for Evaluating Nonmetallic Materials for Oxy-
tuted throughout this document.
gen Service
1.2 This test method provides a means for ranking nonme-
G88 Guide for Designing Systems for Oxygen Service
tallic materials as defined in Guide G63 for use in liquid and
G93 Guide for Cleanliness Levels and Cleaning Methods for
gaseous oxygen systems and may not be directly applicable to
Materials and Equipment Used in Oxygen-Enriched En-
the determination of the sensitivity of the materials in an
vironments
end-useconfiguration.Thistestmethodmaybeusedtoprovide
G94 Guide for Evaluating Metals for Oxygen Service
batch-to batch acceptance data. This test method may provide
2.2 Military Document:
a means for evaluating metallic materials in oxygen-enriched
MIL-D-16791 Detergent, General Purpose (Liquid, Non-
atmospheresalso;however,GuideG94shouldbeconsultedfor
ionic), Type One
preferred testing methods.
2.3 American Chemical Society:
1.3 Values stated in SI units are to be regarded as the
Trichloroethylene, Reagent Grade
standard. The values given in parentheses are for information
only.
2.4 Compressed Gas Association:
G-4 Oxygen
1.4 This standard does not purport to address all of the
G-4.1 Cleaning Equipment for Oxygen Service
safety concerns, if any, associated with its use. It is the
G-4.3 Oxygen, Gaseous, Type I B
responsibility of the user of this standard to establish appro-
priate safety, health, and environmental practices and deter- G-4.3 Oxygen, Liquid, Type II B
mine the applicability of regulatory limitations prior to use. G-10.1 Nitrogen, Gaseous, Type I B
See also Section 9. G-10.1 Nitrogen, Liquid, Type II B
1.5 This international standard was developed in accor-
dance with internationally recognized principles on standard-
ization established in the Decision on Principles for the
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
This test method is under the jurisdiction of ASTM Committee G04 on the ASTM website.
Compatibility and Sensitivity of Materials in Oxygen EnrichedAtmospheres and is Available from Standardization Documents Order Desk, DODSSP, Bldg. 4,
the direct responsibility of G04.01 on Test Methods. Section D, 700 Robbins Ave., Philadelphia, PA 19111-5098, http://
Current edition approved Dec. 1, 2017. Published February 2018. Originally dodssp.daps.dla.mil.
approvedin1984.Lastpreviouseditionapprovedin2011asG86 – 98a(2011).DOI: Available fromAmerican Chemical Society (ACS), 1155 Sixteenth Street, NW
10.1520/G0086-17. Washington, DC 20036, http://www.acs.org.
2 6
NASA Handbook 8060.1B, Pressurized Liquid and Gaseous Oxygen Mechani- Available from Compressed Gas Association (CGA), 4221 Walney Rd., 5th
cal Impact Test, Sept. 1981, pp. 4-72. Floor, Chantilly, VA 20151-2923, http://www.cganet.com.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
G86−17
2.5 NASA Standard:
NSS 1740.15 Safety Standard for Oxygen and Oxygen
Systems
2.6 ASTM Adjuncts:
ABMA-Type Impact Tester and Anvil
3. Terminology
3.1 Definitions of Terms Specific to This Standard:
3.1.1 energy threshold, n—the highest impact energy level
at a given pressure for which the passing criteria have been
met.
3.1.2 GOX, n—gaseous oxygen.
3.1.3 LOX, n—liquid oxygen.
3.1.4 mechanical impact, n—ablowdeliveredbyaplummet
that has been dropped from a pre-established height onto a
striker pin in contact with a sample.
3.1.5 reaction, n—a chemical change or transformation in
the sample initiated by a mechanical impact.
3.1.5.1 Discussion—A reaction from ambient pressure,
LOX mechanical impact may be determined by an audible
report, an electronically or visually detected flash, obvious
charring of the sample, sample cup assembly, or striker pin.
3.1.5.2 Discussion—Reactions in pressurized LOX or GOX
are typically indicated by an abrupt increase in test sample
temperature, chamber pressure, and light levels and may be
supplemented by obvious changes in odor, color, or material
appearance as a result of thermal decompositions observed
during examination after the test.
3.1.6 pressure threshold, n—the highest pressure at a given
FIG. 1 Oxygen Impact Test Frame
impact energy level for which the passing criteria have been
met.
11, and Fig. 14), precooled in a sample freezing box (Fig. 6),
4. Summary of Test Method
covered with LOX, and placed in the sample cup assembly
4.1 The mechanical impact test system is designed to
holder seater in the anvil assembly of the impact tester. The
expose material samples to mechanical impact in the presence
plummet is dropped from a selected height onto the striker pin,
of liquid or gaseous oxygen at pressures from ambient to 68.9
which transmits the energy to the test sample. Observation for
MPa (0 to 10 000 psig). The basic test system configuration
any reaction is made and noted. Drop tests are continued using
consists of: an electromagnet, a plummet, plummet guide
a fresh sample, sample cup assembly, and striker pin for each
tracks, plummet hold/release mechanism, base plate, anvil
drop until the threshold level is determined or the test series is
plate, a sample cup assembly holder, sample cup assembly, and
completed.
striker pin (see Fig. 1). For tests conducted under pressure-
NOTE 1—When testing samples that are sometimes capable of initiating
controlled conditions, the anvil plate and sample cup assembly
false reactions with the aluminum cups, use stainless steel disks as false
holder are replaced with a test chamber equipped with a striker
bottoms in the cups. To minimize interaction, insert disks should be used
pin or striker pin counterloader (see Fig. 2), test chamber
between abrasive samples and one-piece cups, or sample cup assemblies/
purge, pressurization and vent systems (see Fig. 3), and a holders with a steel base (Fig. 11 and Fig. 14) should be used in place of
aluminum one-piece cups.
plummet catcher (see Fig. 4). The general procedure is to
prepare the test sample and record significant pretest data.
4.3 For materials tested in pressurized LOX or GOX, each
sample is placed in the test chamber. The test chamber is filled
4.2 Ambient LOX Impact Test—The test conditions (pres-
with liquid or gaseous oxygen, pressurized to the required test
sure and temperature) are the ambient pressure of the test
pressure, and the striker pin or striker pin counterloader is
facility and the boiling point of LOX at that pressure. Each
pressed down against the top of the test sample. The plummet
sample is placed into a sample cup assembly (see Fig. 5, Fig.
is dropped from a selected height onto the striker pin or striker
pincounterloader.Instrumentationdevicesthatmonitorthetest
AvailablefromNationalAeronauticsandSpaceAdminstration(NASA),NASA
chamber interior for pressure, temperature, and light emission
Headquarters, Suite 1M32, Washington, DC 20546.
provide evidence of test sample reaction. The sample is
Detailed drawings from the ABMA-Type Impact Tester and Anvil Region
removed from the chamber, and the sample is inspected for
Assembly are available at a nominal fee fromASTM International, 100 Barr Harbor
Dr., Philadelphia, PA 19428. Request Adjunct ADJD2512. other evidence of reaction such as odor or charring. Drop tests
G86−17
1 Pneumatic Amplifier Chamber 9 High-Pressure Chamber
2 Equalizer Pin Anvil 10 Sample Cup Assembly
3 Equalizer Pin 11 Anvil Nut
4 Pneumatic Amplifier Diaphragm 12 High-Pressure Seal
5 Pneumatic Amplifier Chamber GN 13 Pressurization Port
Cavity 14 Vent Port
6 and 8 Striker Pin 15 Sightglass for Photocell
7 High-Pressure Seal
FIG. 2 Two Types of High-Pressure Test Chambers
are continued using a fresh sample, sample holder, and striker 4.4 This test method may be used to determine the impact
pin or striker pin counterloader for each drop, until the sensitivity of a material, batch-to-batch acceptance, or to
threshold level is determined or the test series is completed.
satisfy other prescribed pass-fail criteria.
Additional modifications to the above procedure are required
when testing is performed at temperatures above ambient.
G86−17
FIG. 3 Typical Pressurization Piping system for a LOX/GOX Pressurized Test System
NOTE 1—Break sharp edges
NOTE 2—All surfaces to be 0.40 µm (16 µin.) or smoother.
NOTE 3—The thickness and parallelity of the cup bottom shall be
FIG. 4 Typical Plummet Rebound Limiter Assembly controlled to 2.0 mm by coining.
NOTE 4—Material: Aluminum 5052 temper H32.
FIG. 5 LOX Impact Tester One-Piece Sample Cup Assembly
5. Significance and Use
5.1 This test method evaluates the relative sensitivity of
materials to mechanical impact in ambient pressure liquid
oxygen, pressurized liquid oxygen, and pressurized gaseous
5.3 Suggested criteria for discontinuing the tests are: (1)
oxygen.
occurrence of two reactions in a maximum of 60 samples or
less tested at the maximum energy level of 98 J (72 ft•lbf) or
5.2 Any change or variation in test sample configuration,
one reaction in a maximum of 20 samples tested at any other
thickness, preparation, or cleanliness may cause a significant
change in impact sensitivity/reaction threshold. energy level for a material that fails; (2) no reactions for 20
G86−17
FIG. 6 Typical Sample Freezing Box
samples tested at the 98-J (72-ft•lbf) energy level; or (3) a 6.4 The material shall show none of the following reactions
maximumofonereactionin60samplestestedatthemaximum during any of the tests.
energy level.
6.4.1 Audible explosion.
6.4.2 Flash (electronically or visually detected).
6. Criteria for Acceptance for Ambient LOX and
6.4.3 Evidence of burning (obvious charring, see Note 2).
Pressurized LOX and GOX Mechanical Impact Test
6.4.4 Major discoloration (as a result of ignition only rather
6.1 To meet the requirements for acceptability, the material
than other phenomena).
shall show no reaction when being subjected to 20 successive
6.4.5 A temperature or pressure spike in elevated tempera-
impact tests tested at 98 J (72 ft•lbf) using the equipment
ture tests.
described in Section 10.
6.2 The test may be discontinued and the materials consid-
NOTE 2—A burnt odor alone is not considered sufficient proof that a
ered to have failed if there is one reaction in 20 drops at any reaction has occurred. If a reaction occurs (including those during bounce
of plummet), it shall be reported as evidence of sensitivity. Inclusion of
energy level less than 98 J (72 ft•lbf).
bounce reactions applies to ambient LOX mechanical impact tests only.
6.3 Amaterial is acceptable after 60 successive impact tests
6.5 All materials that fail and remain candidates for use
withnotmorethanonereactionat98J(72ft•lbf).Thetestmay
shall be subjected to LOX or GOX mechanical impact energy
be terminated and the material considered to have failed if
there are two reactions in 60 tests or less at 98 J (72 ft•lbf). threshold determinations in the thickness of use.
G86−17
6.6 The material to be tested must be traceable back to the 7.2.2 Preparing Samples to the Proper Dimensions:
original manufacturer and to a specific batch or lot numbers, or 7.2.2.1 Materials normally used in thicknesses greater than
both. 6.35 mm ( ⁄4 in.) shall be sized and tested as 17.5-mm diameter
disks of 6.35 6 0.13-mm (0.250 6 0.005-in.) thickness.
6.7 The thickness of the sample shall be the worst-case
Failure of samples to meet the requirements of this test method
thickness. While the worst-case thickness has been found to
shall be cause for the rejection of the material. Greases, fluids,
vary from material to material, the general trend has been that
and other materials, whose thicknesses are directed by condi-
thinner samples of materials are more reactive.
tions of use, shall be tested as 1.27 6 0.13-mm (0.050 6
6.8 For the ambient LOX impact test, test conditions (pres-
0.005-in.) layers in insert cups. Materials not readily available
sure and temperature) are the ambient pressure of the test
in sheet form shall be tested in the available configuration.
facility and the boiling point of LOX at that pressure. For the
Specimens shall be free of ragged edges, fins, or other
pressurized test, test conditions (pressure and temperature)
irregularities.
shall be determined for each test according to the requirements
NOTE 3—Unless otherwise requested by procuring authority, the test
specified by the requester.
facility should filter all test liquids using ≤5 micron filters to prevent
6.9 Preparation of the samples for testing involve the
particulate contamination.
following tasks.
7.2.2.2 Preparation of Liquid Samples as Supplied—
6.9.1 Receiving the visually inspecting the material,
Prepare a homogenous sample. A microburet may be used to
6.9.2 Preparing the sample to the specified dimensions,
transfer the specimen into the sample cup assemblies. For
6.9.3 Cleaning the samples, and
viscous materials, a microsyringe may be used. Determine the
6.9.4 Inspecting the samples.
volume of the sample required to obtain a sample thickness of
1.27 6 0.13 mm (0.050 6 0.005 in.) and transfer directly into
7. Sample Preparation
the sample cup assembly or insert cup before freezing. (This
7.1 Test material requirements and documentation:
determinationisrequiredduetovariationsfromliquidtoliquid
7.1.1 Traceability—The material to be tested may be trace-
in physical properties such as density, surface tension, and
able back to the original manufacturer and to specific batch or
volatility.) A micrometer depth gage with leveling blocks is
lotnumbers,ortoboth.Whenreceived,thetestmaterialshould
suggested for measurement. The work table must be level. If
be accompanied by proper identification (for example, product
testing in liquid oxygen is to be performed in LOX, check the
data sheets, batch or lot numbers) identifying the sample,
thickness of four liquid samples after they are frozen and
material manufacturer, and appropriate material safety data
record. Limit exposure to atmosphere during preparation of
sheets. It is the responsibility of the procuring authority to
liquid samples and prepare all samples to be tested for the day
identify material traceability.
simultaneously.
7.1.2 Usage Conditions—The worst-case usage thickness,
7.2.2.3 Preparation of Liquid Samples, Concentrated—
conditions and any cleanliness requirements shall be identified
Concentrate the liquid specimens of cleaning agents before
by the procuring authority.
their addition to the one-piece sample cup assembly if accep-
7.1.3 Minimum Recommended Material Quantities—
tance is based on a nonvolatile residue insensitivity require-
Sufficient material shall be available to permit preparation and
ment. Concentrate the liquid sample to 2 % of its original
testing of 140 separate samples as defined in Table 1.
volume by evaporating the sample in a large round-bottom
7.2 Test Material Receiving and Sample Processing
7.2.1 Receiving and Inspection—Upon receipt the testing
facility shall inspect the supplied test material and documen-
tation to verify that all requirements of subsection 7.1 have
been met. The material shall be inspected and any flaws shall
benotedanddiscussedwiththeprocuringauthority.Additional
cleaning procedures shall be implemented if required by the
procuring authority.
TABLE 1 Recommended Minimum Quantities of Material
Required for Testing
A
Material Form Minimum Quantities
2 2
Sheets 2000-cm (319-in. ) total area by 3.5-mm ( ⁄8-in.)
maximum thickness
Coatings, inks, and 120 cm (4 fluid oz.)
adhesives
2 2
Foams 2000-cm (310-in. ) total area by 3.5-mm ( ⁄8-in.)
maximum thickness
Insulated wires 267 cm (105 in.) in length
A
Actual test configurations and material quantities for material forms other than
NOTE 1—Material: stainless steel 300 series.
thoselisted(forexample,O-ringsandseals)mustbeestablishedandapprovedby
NOTE 2—Break all sharp edges 0.19 mm.
the responsible procurement or user materials organization.
FIG. 7 LOX Impact Tester Insert Cup
G86−17
flask heated in a constant-temperature water bath, at a tem- performed using virgin substrate discs, cleaned by the same
perature no higher than 5 °C below the boiling point of the process as those used for the test samples.
sample. Pass air over the surface of the sample at a rapid rate. 7.2.2.5.1 Reactions involving materials prepared on alumi-
Apotential apparatus and procedure for the sample preparation num disks have the potential to be extremely severe as a result
is given in Annex A1, Method A. Add the 2 % concentrated
of ignition of the aluminum disk, which may be initiated by a
sample to the one-piece sample cup assembly, two-piece reaction of the test material. For this reason, insert discs (Fig.
sample cup assembly base, or insert cup until a thickness of
8) are typically used for preparing this type of material.
1.27 6 0.13 mm (0.050 6 0.005 in.) is obtained. If testing is
7.2.2.6 Preparation of Greases and Semisolids—Press a
to be performed in LOX, check the thickness of four liquid
sufficient amount of sample material (a slight excess) into an
samples after they are frozen and record. Limit exposure to
insert cup or the sample recess of a two-piece sample cup
atmosphere during preparation of liquid samples and prepare
assembly 1.27 6 0.13 mm (0.050 6 0.005 in.) deep (see Fig.
all samples to be tested for the day simultaneously.
7) with a cleaned, stainless steel spatula to form a uniform
7.2.2.4 PreparationofLiquidSampleResidues—Place5mL
sample free of bubbles and void areas. Scrape the excess
of the concentrated sample (obtained as is described in 7.2.2.3)
sample level to the rim of the insert/recessed sample cup until
in the one-piece sample cup assemblies or insert cups and heat
a smooth surface is obtained. It is necessary to fill the cup
in an oven at 5°C below the boiling point. Blow filtered air
uniformly. Store the prepared cups in a clean container until
over the samples and remove the vapors by vacuum.Adetailed
required for testing.
description of the apparatus and the procedure is presented in
7.2.2.7 Preparation of Solids—Cut and prepare samples of
Annex A2, Method B. If testing is to be performed in LOX,
solid material to a diameter of 17.5 to 19.1 mm (0.69 to
check the thickness of four liquid samples after they are frozen
0.75 in.). Sheet material not available in 1.52 6 0.13-mm
and record. Limit exposure to atmosphere during preparation
(0.060 6 0.005-in.) thickness is tested in the thickness in-
of liquid samples and prepare all samples to be tested for the
tended for use when that thickness is not more than 6.35 mm
day simultaneously.
(0.250 in.). Materials normally used in a thickness greater than
7.2.2.5 Leak Check Compounds, Dye, Dye Penetrant, and
6.35mm(0.250in.)arecuttoprovidedisksof6.35 60.13mm
Emulsifier—Clean, unsealed, undyed sulfuric acid-anodized
(0.250 6 0.005-in.) thickness.
6061-T6 aluminum alloy disks (or other substrate specified by
7.2.2.8 Sample Preparation of Material Configurations In-
the manufacturer or requester as a means to simulate end-use
suffıcient for Standard Sample Fabrication—Cut or otherwise
configuration), of similar dimensions to the insert disk (Fig. 8)
section the test material into small pieces 1.27 to 6.35 mm
are used as a substrate. When appropriate, insert disks maybe
(0.05-0.25 in.) along each dimension and combine multiple
used as the substrate disc. Clean the disks before use (see
pieces to form a collection of uniform thickness constituting an
11.2.2.1). After cleaning, dip new anodized disks in the test
individual test sample with a total mass of 400 to 600 mg
materials for 15 min and drain for 15 min with the disks
(0.0141 to 0.0212 oz).
oriented vertically. Cure the sample as specified, then store the
prepared disks in a clean container until required for testing. If
NOTE 4—This method is only intended for use when a material’s usage
the substrate disc is not a standard Insert Disc, blank insert disc
configuration renders all other preparation methods impractical.
test checks (see 11.4) preformed during testing shall be
7.2.2.9 Preparation of Solder (Solid or Flux-Core Type)—
Prepare solder samples as follows: melt the solder (solid or
flux-core type) at a temperature no higher than 25°C above the
melting point of the solder in a mold to form an ingot. Roll the
ingottoformaflatsheet0.51 60.13(0.020 60.005in.)thick.
Punch disks of 17.5-mm ( ⁄16-in.) diameter from the sheet.
Clean the disks by detergent washing, water rinsing, drying,
and vapor degreasing in an appropriate solvent. Store the
prepared samples in a clean container until required for testing.
7.2.2.10 Preparation of Coatings, Paints, Adhesives, and
Potting Compounds—Materials of this type are prepared as
follows.
(1) Coating materials (such as paints, dry film lubricants,
and conformal coatings) shall be applied to 17.5-mm ( ⁄16-in.)
diameter by 1.6-mm (0.063-in.) thick 300 series stainless steel
disks in the same manner and to the same thickness intended
for use. After the samples have dried, they shall be placed in
the regular sample cup assemblies for ambient pressure testing
and used as prepared in the pressurized impact tester.
(2) Elastomeric coatings and adhesives shall be applied as
acoatingto300stainlesssteeldisksusingMethod1orMethod
NOTE 1—Material: Type 347 stainless steel.
2 described below and cured according to applicable instruc-
NOTE 2—Break all sharp edges 0.19 mm.
FIG. 8 Insert Disk tions.
G86−17
(a) Method 1 (Single-Dip Coat)—Dip coat insert disks to (25-µm absolute or smaller filter rating) distilled water, and
specified thickness and place on clean aluminum foil or on using filtered (25-µm absolute or smaller filter rating), dry, low
polytetrafluoroethylene (PTFE) to air dry. The coated inserts hydrocarbon air or inert gas. If necessary, the samples may be
shall be removed from the foil and turned over after 30 min to cleaned by rinsing with an oxygen-compatible solvent that is
allow both sides to dry. The specimens shall be cured as compatible with the test material, prior to the fore mentioned
specifiedbeforetesting.Thecoatingthicknessshallbechecked cleaning procedure.
on at least four samples and recorded. 7.2.3.3 If the sample material cannot be wetted with any
(b) Method 2 (Brush Coat)—Material shall be applied cleaning solution without altering the test sample, the samples
onto insert disks using a single brush stroke with a soft shall be blown clean using filtered (25-µm absolute or smaller
nonshedding brush, in single brush coats of finished coating as filter rating), dry, low hydrocarbon air or inert gas.
specified. Each specimen shall be visually examined for
7.3 Nonmetallic, Solid, Metallic, and Solvent-Resistant
contamination (especially bristles from the brush) following
Samples—If received in a certified clean condition, test in the
application of each coat. The coated specimens shall be air
as-received condition. Otherwise, clean the sample before
dried for a minimum of 24 h following application of the final
testing by rinsing with tap water, then washing in nonionic
coat before testing.
detergent solution, then finally rinsing in DI water. Drain for a
7.2.2.11 O-Rings—Each size from each batch of O-rings or
minimum of 10 min and dry using a gaseous nitrogen purge.
O-ring materials or both shall be sampled and tested as follows
unless it can be demonstrated that test results on different sizes
8. Reagents and Materials
and batches are comparable. To clean O-rings before testing,
8.1 Alkaline Cleaner, for test chambers, striker pins, sample
rinse with tap water, rinse in nonionic detergent solution, rinse
cup assemblies, and sample holder units, consisting of a
in DI water, drain for a minimum of 10 min, and dry using a
solution of 15 g of sodium hydroxide (NaOH), 15 g of
gaseous nitrogen purge.
trisodium phosphate (Na PO ), and 1 L of distilled or deion-
11 3 4
(1) Extruded O-Rings140 sample disks 17.5-mm ( ⁄16-in.)
ized water.
diameter by the thickness of the O-rings shall be cut from a
strip after the chopping operation. The disks shall be similarly 8.2 Deionized Water, conforming to Specification D1193,
processed and deflashed with the same equipment used for the Type IV.
O-rings.Thedisksshallbecleanedasspecifiedforthematerial
8.3 Detergent, a noncorrosive cleaner that is compatible
and its use.
with liquid oxygen in the concentration used, conforming to
(2) Molded O-Rings140 sample disks 17.5-mm ( ⁄16-in.)
MIL-D-16791.
diameter by the thickness of the O-rings, and which have been
8.4 Gaseous Oxygen, conforming to CGA G–4.3 Type I B.
similarly processed and deflashed, shall be furnished.
Oxygen of higher purity may be used if desired (see Note 5).
(3) O-Rings From Standard Stock or Where Above Proce-
duresAreImpracticalO-rings1.27-cm( ⁄2-in.)outsidediameter 8.5 Liquid Oxygen, conforming to CGA G–4.3, Type II B.
or less shall be sampled and tested as a complete O-ring.
NOTE 5—Gaseous mixtures of the appropriate oxygen concentration
O-rings larger than 1.27-cm ( ⁄2-in.) outside diameter shall be
and certified analysis may be purchased commercially.
tested as one segment (approximately 1.91 cm ( ⁄4-in.) long).
8.6 Gaseous Nitrogen, CGA G–10.1, Type IB.
To clean O-rings before testing, rinse with tap water, wash in
8.7 Liquid Nitrogen, CGA G–10.1, Type IIB.
nonionic detergent solution, rinse in DI water, drain for a
minimum of 10 min, and dry using a gaseous nitrogen purge.
8.8 Trichloroethylene, ACS reagent grade or Specification
If a sample is not impacted during testing, it shall be placed in
D4080.
a new sample cup assembly and precooled before retesting.As
an alternative, sufficient samples may be prepared to account
9. Safety Precautions
for the normal impact misses.
9.1 LOX
7.2.2.12 Heat Shrink Tubing—Heat shrunk tubing shall be
9.1.1 When testing is to be performed in liquid oxygen,
preshrunkbeforetestinginaccordancewiththemanufacturer’s
normal safety precautions applicable to the handling and use of
instructions.
liquid oxygen must be used.
7.2.2.13 Insulated Wires—Tests samples shall be cut to 17.5
9.1.2 The hazards associated with handling oxygen are very
to 19.1 mm (0.69 to 0.75-in.) lengths. Ends shall remain
serious. Contact with the skin can cause frostbite. Contact of
unstripped. Test samples shall be straightened as much as
liquid oxygen with hydrocarbons or other fuels constitutes a
possible and tested in this configuration.
fire or explosion hazard because such mixtures can be sensitive
7.2.3 Cleaning—The samples should be cleaned by the
to shock, impact, or vibration.
same method that will be used in the material application.
9.1.3 Personnel working with liquid oxygen must be famil-
7.2.3.1 Test in the as-received condition when the test
iar with its characteristics. Approved goggles or face shields,
material is received in a certified clean condition or customer
fire-retardant protective clothing, gloves, and boots must be
specified final use condition.
worn during handling or transfer. Such operations should be
7.2.3.2 If the cleaning procedure is not specified, clean the performedbynolessthantwopersons,asaminimum.Extreme
sample before testing by rinsing with tap water, then washing caution should be exercised in preventing contact with oils or
in a nonionic detergent solution, then rinsing with filtered other combustible materials. All tools must be degreased
G86−17
before use. Precautions should be taken to prevent accumula- 9.2.4 Equipment used in a 69-MPa (10 000-psig) oxygen
tion of moisture in lines, valves, traps, and so forth to avert system must be properly designed and rated for oxygen
freezing and plugging which would cause subsequent pressure service. Proper design of high-pressure oxygen systems in-
ruptures. Care should also be taken to prevent undesired cludes designing for minimum internal volumes, thereby lim-
entrapment of liquid oxygen in unvented sections of any iting the magnitude of catastrophic reactions that may occur
system. while testing materials. Components such as valves, pressure
regulators, gages, filters, and the like, must be fabricated from
9.1.4 Direct physical contact with LOX, cold vapor, or cold
materials that have a proven record of suitability for high-
equipmentcancauseserioustissuedamage.Medicalassistance
pressure oxygen service. Examples of such materials are
should be obtained as soon as possible for any cold injury.
Monel 400, Inconel 600, nickel, and selected stainless steels
Proper immediate bystander response be as follows:
(see Note 6).
9.1.4.1 If it is safe to do so, remove the patient from the
source of the cold.
NOTE 6—Where not otherwise indicated, stainless steel shall be of the
AISI 300 series.
9.1.4.2 In the event of limb-size cryogenic exposure, appro-
priate response may include an attempt to warm the affected
9.2.5 High-pressure oxygen systems require the utmost
area rapidly with moist heat from a shower, eyewash, or warm
cleanliness. Therefore, components should be designed to
water bath, not exceeding 39°C (102°F).
facilitatedisassembly,thoroughcleaning,andreassemblywith-
9.1.4.3 Massive full-body cryogenic exposures present sig-
outcompromiseofcleanlinesslevel.Screeningtestsperformed
nificantadditionalconcerns,butremovalofthevictimfromthe
onnonmetallicmaterialshaveshownthattheimpactsensitivity
exposure atmosphere and keeping the victim’s airway open are
of these materials can vary from batch to batch. Since
important. Loosely wrapping the victim in a blanket until the
nonmetallic materials are usually the most easily ignited
arrival of the ambulance team is also advised.
components in a high-pressure oxygen system, nonmetallic
9.1.4.4 Some important don’ts: don’t remove frozen gloves, items to be used in this test apparatus, such as seats, seals, and
shoes, or clothing; salvageable skin may be pulled off inadver-
gaskets, should be chosen from the best (that is, least sensitive)
tently.Don’tmassagetheaffectedpart;don’texposethepartto available batch of material.
temperatures higher than 45°C (112°F), such as heat or fire;
9.2.6 The test chamber shall be isolated from the oxygen
this superimposes a burn and further tissue damage; don’t
source by a double-block-and-bleed valve arrangement con-
apply, ice, snow, or ointments.
sisting of two block valves in series with a vent valve between
9.1.5 Safety shower and other protective equipment should them. Each block valve shall be locked closed and the vent
be inspected periodically to ensure that they are operational valve locked open whenever personnel are working in test cell.
when needed. Personnel handling liquid oxygen must ensure By ensuring two-valve isolation and continuous venting, the
that oxygen vapors do not remain absorbed in their clothing chance of exposing personnel to high-pressure oxygen as a
before smoking or approaching any source of ignition. Des- result of inadvertent valve actuation or leakage during sample
orption of oxygen may be accomplished by remaining in a changeout is minimized (see Fig. 9).
well-ventilated area for 30 min after exiting the test area.
9.2.7 When testing is to be performed at elevated
temperature, normal safety precautions applicable to the op-
9.2 GOX
eration and maintenance of electrical systems must be fol-
9.2.1 This is a hazardous test. Normal safety precautions
lowed.
applicable to the operation and maintenance of high-pressure
9.2.8 The sample heater, heater wiring, and control system
gas systems must be followed when working with the test
must be designed for continuous usage. Adequate precautions
system.
must be taken to eliminate the potential for electrical shock.
9.2.2 Complete isolation of personnel from the test appara-
The heater circuit shall be equipped with a safety switch and
tus is required whenever the test chamber contains a test
warning lights in the immediate vicinity of the tester to permit
sample and is pressurized above atmospheric pressure with
personnel working on the test chamber to assess the condition
oxygen. Violent reactions between test materials and high-
oftheheatercircuit.Alocalmethodofopeningthecircuitmust
pressure oxygen must be expected at all times. Test chamber
be provided in the test chamber area which is in series with the
component failure caused by violent test sample reaction has
control area heater control switch. A typical instrumentation
produced shrapnel, flying objects, dense smoke, and high-
control system is shown in Fig. 3.
pressure gas jets and flames inside the test cell.Test cell design
9.2.9 When performing tests at elevated temperatures, per-
and layout, test procedures, personnel access controls, and
sonnel must wear heat-resistant gloves for handling hot com-
emergency shutdown procedures must be designed with this
ponents or allow the heated components to cool completely
type of failure expected any time the test system contains
before handling them.
oxygen.
9.3 Trichloroethylene
9.2.3 Complete isolation is assured by locating the test
apparatus in an enclosure and behind an barricade. The 9.3.1 Warning—Harmful if inhaled. High concentrations
operator is stationed in a control room on the other side of the may cause unconsciousness or death. Contact may cause skin
barricade. Visual observation of the test shall be accomplished irritationanddermatitis.Avoidprolongedorrepeatedbreathing
by means such as a reinforced window, periscope, mirrors, or ofvapororspraymist.Useonlywithadequateventilation.Eye
closed-circuit television. irritation and dizziness are indications of overexposure. Do not
G86−17
FIG. 9 Typical Instrumentation/Control Diagram for Pressurized LOX/GOX System
take internally. Swallowing may cause injury, illness, or death. vice” for details of safe practice in the use of oxygen. Practice
Avoid prolonged or repeated contact with skin. Do not get in G93 may be consulted for cleaning practices also.
the eyes. Do not allow to contact hot surfaces, since toxic
10. Test Apparatus
products can be formed.
10.1 Ambient Mechanical Impact Test System—The impact
9.4 Oxygen
tester for the ambient LOX impact test shall have a rugged
9.4.1 Warning—Oxygen vigorously accelerates combus-
structural frame capable of maintaining accurate vertical align-
tion. Keep oil and grease away. Do not use oil or grease on
ment under repeated shock conditions (see Fig. 1), a mecha-
pressure regulators, gages, or control equipment, except as
nism for dropping a plummet which weighs 9.072 6 0.023 kg
suggestedbyGuideG63.GuidesG63,G88,andG94shouldbe
(20 6 0.05 lb) (see Note 7) through a distance of 1.10 6 0.005
usedintheselectionofmaterialsusedintestsystems.Useonly
m (43.3 6 0.2 in.), which will transmit to the test sample an
with equipment conditioned for oxygen service by carefully
approximate impact energy of 98 J (72 ft•lbf), a striker pin (see
cleaning to remove oil, grease, and other combustibles. Keep
Fig. 10) nominally 1.27 cm ( ⁄2 in.) in diameter and 5.08 cm (2
combustibles away from oxygen and eliminate ignition
in.) long, and a one- or two-piece sample cup assembly (see
sources. Keep surfaces clean to prevent ignition or explosion,
Fig. 5 and Fig. 11) approximately 2.22-cm ( ⁄8-in.) inside
or both, on contact with oxygen. Always use a pressure
diameter by approximately 2.22-cm ( ⁄8-in.) inside depth made
regulator. Release pressure regulator tension before opening
from 0.16-cm ( ⁄16-in.) thick aluminum alloy. The initial
the cylinder valve.All equipment and containers used must be
alignment and subsequent operation of the impact tester shall
suitable and recommended for oxygen service. Never attempt
be such that the plummet falls uniformly under essentially
to transfer oxygen from the cylinder in which it is received to
friction-free conditions. This shall be verified by suitable
any other cylinder. Do not mix gases in cylinders. Do not drop
meansoneachdroptoensurethat 63 %ofthetheoreticaldrop
the cylinders. Make sure cylinders are maintained upright and
time is attained. Measurement shall be made as close to the
secured at all times. Keep cylinder valves closed and capped
striker pin as possible. See Section 12 for the calibration of the
when not in use. Stand away from outlet when opening a
impact tester.
cylindervalve.Fortechnicaluseonly;donotuseforinhalation
purposes. Keep cylinders out of sun and away from heat. Keep
NOTE 7—The weight times the drop height specified is not duplicated
for the purposes of this test by combinations other than 9.072 6 0.023 kg
cylinders away from corrosive environments. Do not use a
(206 0.05 lb) through a distance of 1.10 6 0.005 m (43.3 + 0.2 in.). For
cylinder without a label. Do not use dented or damaged
example, doubling the mass of the plummet and halving the drop height
cylinders.
would not duplicate the specified requirement. Drop height shall be
9.4.2 See Compressed Gas Association Pamphlets G-4,
measured from the nose of the plummet to the top of the striker pin with
“Oxygen” and G-4.1, “Cleaning Equipment for Oxygen Ser-
the cup and stainless steel disk in position.
G86−17
10.1.1.2 Safety Catch—The solenoid-operated safety catch
shall be designed to hold the plummet near the base of the
magnet in the event of a power failure.
10.1.1.3 Base Plate—The base shall be constructed from
2.54-cm (1-in.) minimum thick stainless steel plate and shall
rest solidly and level on a base of reinforced concrete. It is
recommendedthatgroutbeappliedtopreventanyspilledLOX
from being trapped under the steel plate. A minimum of four
stainlesssteelfoundationboltsshallbeusedtoanchortheplate
to the concrete.
10.1.1.4 Anvil Plate and Sample Cup Assembly Holder (see
Fig. 12)—A stainless steel, Type 440B, or equivalent, heat-
treated (56 to 58 Rockwell Hardness C (HRC)) anvil plate 12.7
by 12.7 by 5.1 cm (5 by 5 by 2 in.) thick, shall be bolted to the
NOTE 1—Break sharp edges.
base plate in the center of the machine. This plate shall center
NOTE 2—Machine all surfaces to 0.40 mm (16 µin.) or smoother.
thesamplecupassemblyholderandprovidethebaseplatewith
NOTE 3—Material: stainless steel AMS 5643D (17-4 PH).
protection from denting upon impact. A 12.7- by 12.7-cm (5-
NOTE 4—Heat treatment: obtain H900.
by5-in.)stainlesssteelsamplecupassemblyholder,2.54cm(1
NOTE 5—Finish: electropolish after heat treatment (measured immedi-
in.) thick, shall be bolted on top of the anvil plate. The sample
ately after manufacturing).
cup assembly holder shall have a slightly tapered hole into
NOTE 6—Surfaces A and B should be parallel and perpendicular to the
center line.
which the test sample cup assembly can be placed.
FIG. 10 LOX Impact Striker Pin
10.1.1.5 Sample CupAssembly—Several samplecupassem-
bly designs are available for use depending on material type
and test configuration.
(1) One-Piece Sample Cup Assembly—One-piece sample
cup assemblies (see Fig. 5) shall be made of aluminum 5052,
temper H-32.
(2) Multi-Piece Sample Cup Assembly—Multi-piece
samplecupassembliesconsistofabase,sleeveandanoptional
centering ring (centering ring shown in Fig. 14). Multi-piece
sample cup assembly designs may include a base with a recess
for testing liquid and semisolid materials without the use of
insert cups. Two designs are currently in use:
(a) Inconel base, stainless steel sleeve, and stainless steel
centering ring (Fig. 14).
(b) 17-4PH base, PTFE sleeve, and brass centering ring
as required (Fig. 11).
(3) Inserts:
(a) Insert Cup—An insert cup may be used when testing
liquid or semisolid materials, and are placed inside the one- or
multi-piecesamplecupassemblies.Insertcupsaremadeofany
stainless 300 series stainless steel (see Fig. 7 and Fig. 14) with
aninsidedepthof1.27mm 60.13mm(0.050 60.005in.).No
insertcupisrequiredforsolidmaterials;solidmaterialsamples
are placed directly on top of the sample holder plate and
NOTE 1—Break sharp edges 0.19 mm.
retained under the striker pin by a centering ring. Insert disks
NOTE 2—Material: Typically 17-4PH H900 stainless steel alloy (base);
and insert cups should not be used together.
PTFE (sleeve).
(b) Insert Disk—Insert disks (see Fig. 8) are used as the
NOTE 3—PTFE sleeve is intended to have an interference fit with the
substratefortheapplicationoftestmaterialsandduringsystem
base.
FIG. 11 LOX Impact Tester Two-Piece Cup Assembly cleanliness verification (see 11.4).
One-piece sample cups (see ) shall be made of any dead soft
3000 or 5000 series aluminum alloy.Aspecial insert cup made
10.1.1 The tester also consists of the following parts:
of any 3000 or 5000 series aluminum alloy (see Fig. 7) with an
10.1.1.1 Electromagnet—The electromagnet (if used) shall
inside depth of 0.127 6 0.013 cm (0.050 + 0.005 in.) shall also
be designed with a sufficient safety factor to hold over 9.08 kg
be used when testing semisolid materials. These special insert
(20 lb) of weight with a minimum energizing wattage. Me-
cups shall be placed inside the one-piece specimen cups.
chanical suspension/release devices shall be designed with a
sufficient safety factor to hold a 9.08-kg (20-lb) plummet 10.1.1.6 Striker Pins—The striker pins shall be made from
positively. 17-4 PH (AMS 5643D) stainless steel, or equivalent, with
G86−17
FIG. 12 LOX Impact Tester Sample Cup, Sample Cup Holder, Striker Pin, and Anvil Configuration
catch and electromagnet, and timing instrumentation to mea-
sure the drop time of the plummet or its velocity just before
impact.
10.1.1.8 Timer—Auniversal counter and timer shall be used
to measure drop time. The overall drop time shall be measured
and recorded for each drop to ensure that the rated accuracy of
the equipment is maintained.Atypical timing circuit is shown
in Fig. 13.
10.1.1.9 Plummet Catcher—The plummet catcher limits the
plummet to one impact on the striker pin per test (see Fig. 4).
This component is optional, but has been found to improve test
repeatability.
10.1.1.10 Test Cell—The impact tester shall be housed in a
test cell with a concrete floor. Walls shall be constructed of
reinforced concrete or metal to provide protection from explo-
sion or fire hazards. The cell shall contain a shatterproof glass
observation window. It shall be darkened sufficiently for
observation of flashes. Continuous ventilation shall provide
fresh air to the test cell. Construction of the test cell shall be
directed at providing a facility that can be economically
maintained at a high level of good housekeeping.
10.2 Pressurized Mechanical Impact Test System—The me-
chanicalimpacttestsystemusedfordeterminingthesensitivity
FIG. 13 Typical Free-Fall Timing Circuit
of materials to mechanical impact in pressurized LOX or GOX
is similar to theAB
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