ASTM G86-98a

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Designation: G 86 – 98a
Standard Test Method for
Determining Ignition Sensitivity of Materials to Mechanical
Impact in Ambient Liquid Oxygen and Pressurized Liquid
and Gaseous Oxygen Environments
ThisstandardisissuedunderthefixeddesignationG 86;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginal
adoption or, in the case of revision, the year of last revision.Anumber in parentheses indicates the year of last reapproval.Asuperscript
epsilon (e) indicates an editorial change since the last revision or reapproval.
1. Scope Liquid Oxygen (Impact Sensitivity Threshold and Pass-
2 Fail Techniques)
1.1 This test method describes test equipment and tech-
D 1193 Specification for Reagent Water
niques to determine the impact sensitivity of materials in
D 4080 Specification for Trichloroethylene, Technical and
oxygen under two different conditions: (1) in ambient pressure
Vapor Degreasing
liquid oxygen (LOX) or (2) under pressure-controlled condi-
G 63 Guide for Evaluating Nonmetallic Materials for Oxy-
tions in LOX or gaseous oxygen (GOX). It is applicable to
gen Service
materials for use in LOX or GOX systems at pressures from
G 88 Guide for Designing Systems for Oxygen Service
ambient to 68.9 MPa (0 to 10 000 psig). The test method
G 93 Practice for Cleaning Methods for Materials and
described herein addresses testing with pure oxygen environ-
Equipment Used in Oxygen-Enriched Environments
ments; however, other oxygen-enriched fluids may be substi-
G 94 Guide for Evaluating Metals for Oxygen Service
tuted throughout this document.
2.2 Military Document:
1.2 This test method provides a means for ranking nonme-
MIL-D-16791 Detergent, General Purpose (Liquid, Non-
tallic materials as defined in Guide G 63 for use in liquid and
ionic), Type One
gaseous oxygen systems and may not be directly applicable to
2.3 American Chemical Society:
the determination of the sensitivity of the materials in an
Trichloroethylene, Reagent Grade
end-useconfiguration.Thistestmethodmaybeusedtoprovide
2.4 Compressed Gas Association:
batch-to batch acceptance data. This test method may provide
G-4 Oxygen
a means for evaluating metallic materials in oxygen-enriched
G-4.1 Cleaning Equipment for Oxygen Service
atmospheres also; however, Guide 94 should be consulted for
G-4.3 Oxygen, Gaseous, Type I B
preferred testing methods.
G-4.3 Oxygen, Liquid, Type II B
1.3 Values stated in SI units are to be regarded as the
G-10.1 Nitrogen, Gaseous, Type I B
standard. The values given in parentheses are for information
G-10.1 Nitrogen, Liquid, Type II B
only.
2.5 NASA Standard:
1.4 This standard does not purport to address all of the
NSS 1740.15 Safety Standard for Oxygen and Oxygen
safety concerns, if any, associated with its use. It is the
Systems
responsibility of the user of this standard to establish appro-
priate safety and health practices and determine the applica-
3. Terminology
bility of regulatory limitations prior to use. See also Section 9.
3.1 Definitions of Terms Specific to This Standard:
2. Referenced Documents 3.1.1 GOX, n—gaseous oxygen.
2.1 ASTM Standards:
D 2512 Test Method for Compatibility of Materials with
Annual Book of ASTM Standards, Vol. 15.03.
Annual Book of ASTM Standards, Vol. 11.01.
Annual Book of ASTM Standards, Vol. 15.05.
1 6
This test method is under the jurisdiction of ASTM Committee G 4 on Annual Book of ASTM Standards, Vol. 14.02.
Compatibility and Sensitivity of Materials in Oxygen EnrichedAtmospheres and is Available from Naval Publications and Forms Center, 5801 Tabor Ave.,
the direct responsibility of G 4.01 on Test Methods. Philadelphia, PA 19120.
8 th
Current edition approved Sept. 10, 1998. Published March 1999. Originally American Chemical Society, 1155 16 St., N.W., Washington, DC 20036.
published as G 86-84. Last previous edition G 86-98. Compressed Gas Association, 1725 Jefferson Davis Highway, Arlington, VA
NASA Handbook 8060.1B, Pressurized Liquid and Gaseous Oxygen Mechani- 22202-4100.
cal Impact Test, Sept. 1981, pp. 4-72. National Aeronautics and Space Adminstration, Washington, DC 20546.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
G86
3.1.2 LOX, n—liquid oxygen.
3.1.3 mechanical impact, n—a blow delivered by a plum-
met that has been dropped from a preestablished height onto a
striker pin in contact with a sample.
3.1.4 reaction, n—a chemical change or transformation in
the sample initiated by a mechanical impact.
3.1.4.1 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, cup, or striker pin.
3.1.4.2 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.
3.1.5 pressure threshold, n—the highest pressure at a given
impact energy level for which the passing criteria have been
met.
3.1.6 energy threshold, n—the highest impact energy level
at a given pressure for which the passing criteria have been
met.
4. Summary of Test Method
4.1 The mechanical impact test system is designed to
expose material samples to mechanical impact in the presence
of liquid or gaseous oxygen at pressures from ambient to 68.9
MPa (0 to 10 000 psig). The basic drop tower configuration
consists of: an electromagnet, a plummet, plummet guide
tracks, plummet hold/release mechanism, base plate, anvil
FIG. 1 Oxygen Impact Test Frame
plate, a specimen cup holder, sample cup, and striker pin (see
Fig. 1). For tests conducted under pressure-controlled condi-
tions,theanvilplateandspecimencupholderarereplacedwith removed from the chamber, and the sample is inspected for
a test chamber equipped with a striker pin or striker pin
other evidence of reaction such as odor or charring. Drop tests
counterloader (see Fig. 2), test chamber purge, pressurization are continued using a fresh sample, sample holder, and striker
and vent systems (see Fig. 3), and a plummet catcher (see Fig. pin or striker pin counterloader for each drop, until the
4). The general procedure is to prepare the test sample and threshold level is determined or the test series is completed.
record significant pretest data. Additional modifications to the above procedure are required
4.2 Ambient LOX Impact Test—The test conditions (pres- when testing is performed at temperatures above ambient.
sure and temperature) are the ambient pressure of the test 4.4 This test method may be used to determine the impact
facility and the boiling point of LOX at that pressure. Each sensitivity of a material, batch-to-batch acceptance, or to
sample is placed into a specimen cup (see Fig. 5), precooled in satisfy other prescribed pass-fail criteria.
a sample freezing box (Fig. 6), covered with LOX, and placed
5. Significance and Use
in the cup holder seater in the anvil assembly of the impact
5.1 This test method evaluates the relative sensitivity of
tester. The plummet is dropped from a selected height onto the
striker pin, which transmits the energy to the test sample. materials to mechanical impact in ambient pressure liquid
Observation for any reaction is made and noted. Drop tests are oxygen, pressurized liquid oxygen, and pressurized gaseous
continued using a fresh sample, sample cup, and striker pin for oxygen.
each drop until the threshold level is determined or the test 5.2 Any change or variation in test sample configuration,
series is completed. thickness, preparation, or cleanliness may cause a significant
4.3 For materials tested in pressurized LOX or GOX, each change in impact sensitivity/reaction threshold.
sample is placed in the test chamber. The test chamber is filled 5.3 Suggested criteria for discontinuing the tests are: (1)
with liquid or gaseous oxygen, pressurized to the required test occurrence of two reactions in a maximum of 60 samples or
pressure, and the striker pin or striker pin counterloader is less tested at the maximum energy level of 98 J (72 ft•lbf) or
pressed down against the top of the test sample. The plummet one reaction in a maximum of 20 samples tested at any other
is dropped from a selected height onto the striker pin or striker energy level for a material that fails; (2) no reactions for 20
pincounterloader.Instrumentationdevicesthatmonitorthetest samples tested at the 98-J (72-ft•lbf) energy level; or (3) a
chamber interior for pressure, temperature, and light emission maximumofonereactionin60samplestestedatthemaximum
provide evidence of test sample reaction. The sample is energy level.
G86
1 Pneumatic Amplifier Chamber 9 High-Pressure Chamber
2 Equalizer Pin Anvil 10 Sample Cup
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
6. Criteria for Acceptance for Ambient LOX and be terminated and the material considered to have failed if
Pressurized LOX and GOX Mechanical Impact Test there are two reactions in 60 tests or less at 98 J (72 ft•lbf).
6.4 The material shall show none of the following reactions
6.1 To meet the requirements for acceptability, the material
during any of the tests.
shall show no reaction when being subjected to 20 successive
6.4.1 Audible explosion.
impact tests tested at 98 J (72 ft•lbf) using the equipment
6.4.2 Flash (electronically or visually detected).
described in Section 10.
6.4.3 Evidence of burning (obvious charring, see Note 1).
6.2 The test may be discontinued and the materials consid-
6.4.4 Major discoloration (as a result of ignition only rather
ered to have failed if there is one reaction in 20 drops at any
energy level less than 98 J (72 ft•lbf). than other phenomena).
6.3 Amaterial is acceptable after 60 successive impact tests 6.4.5 A temperature or pressure spike in elevated tempera-
withnotmorethanonereactionat98J(72ft•lbf).Thetestmay ture tests.
G86
FIG. 3 Typical Pressurization Piping system for a LOX/GOX Pressurized Test System
NOTE 1—Break sharp edges 0.4 mm.
NOTE 2—The cup is formed by deep drawing.
NOTE 3—The thickness and parallelness of the cup bottom shall be
FIG. 4 Typical Plummet Rebound Limiter Assembly
controlled to 2.0 mm by coining.
NOTE 4—Material: any 3000 or 5000 series aluminum alloy.
NOTE 1—A burnt odor alone is not considered sufficient proof that a
FIG. 5 LOX Impact Tester One-Piece Sample Cup
reaction has occurred. If a reaction occurs (including those during bounce
of plummet), it shall be reported as evidence of sensitivity. Inclusion of
bounce reactions applies to ambient LOX mechanical impact tests only.
6.7 The thickness of the sample shall be the worst-case
6.5 All materials that fail 6.1 criteria and remain candidates thickness. While the worst-case thickness has been found to
for use must be subjected to LOX or GOX mechanical impact vary from material to material, the general trend has been that
energy threshold determinations in the thickness of use. thinner samples of materials are generally more reactive.
6.6 The material to be tested must be traceable back to the 6.8 For the ambient LOX impact test, test conditions (pres-
original manufacturer and to a specific batch or lot numbers, or sure and temperature) are the ambient pressure of the test
both. facility and the boiling point of LOX at that pressure. For the
G86
7.1.2 Materials normally used in thicknesses greater than
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 0.006-in.) thickness.
Failure of samples to meet the requirements of this test method
shall be cause for the rejection of the material. Greases, fluids,
and other materials, whose thicknesses are directed by condi-
tions of use, shall be tested as 1.27- 6 0.13-mm (0.050- 6
0.005-in.) layers in special test cups. Materials not readily
available in sheet form shall be tested in the available configu-
ration. Specimens shall be free of ragged edges, fins, or other
irregularities.
7.2 Liquid Samples—Prepare a homogeneous sample. A
microburette may be used to transfer the sample into special
sample cups 1.27 6 0.13 mm (0.050 6 0.005 in.) deep (see
Fig. 7). For highly viscous materials, a microsyringe may be
used. Determine the volume of the sample required to obtain a
sample thickness of 1.27 6 0.13 mm (0.050 6 0.005 in.) in the
FIG. 6 Typical Sample Freezing Box
sample cup. This determination is required due to variations in
such physical properties as density, surface tension, and
pressurized test, test conditions (pressure and temperature)
volatility from liquid to liquid. A micrometre depth gage with
shall be determined for each test according to the requirements
leveling blocks is suggested for measurement. The work table
specified by the requester.
must be level. Test material should be loaded into the sample
6.9 Preparation of the samples for testing involve the
cup just before loading the cup into the test chamber (or
following tasks.
freezing box, if testing in liquid oxygen).
6.9.1 Receiving the visually inspecting the material.
7.3 Leak Check Compounds, Dye, Dye Penetrant, and
6.9.2 Preparing the sample to the specified dimensions.
Emulsifier, Method 1—Clean, unsealed, sulfuric acid-anodized
6.9.3 Cleaning the samples.
6061-T6aluminumalloydisks(oranyothersubstratespecified
6.9.4 Inspecting the samples.
by the manufacturer or requester), 17.5 mm ( ⁄16 in.) in
diameter by 1.60 mm (0.063 in.) thick are used as a carrier.
7. Sample Preparation
Clean the disks before use (see 11.2.2.1). To ascertain the
7.1 The material to be tested must be traceable back to the
effectiveness of the cleaning procedure, test a minimum of 20
original manufacturer and to specific batch or lot numbers, or
blankdisks.Aftercleaningandblanktesting,dipnewanodized
to both. When received, the test material must be accompanied
disks in the test materials for 15 min and drain for 15 min with
by proper identification, for example, product data sheets,
the disks oriented vertically. Cure the sample as specified, then
batch or lot numbers identifying the sample, material manu-
store the prepared disks in a clean container until required for
facturer, and appropriate material safety data sheets. The
testing.
material must be
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