ASTM D2512-95(2002)e1
(Test Method)Standard Test Method for Compatibility of Materials with Liquid Oxygen (Impact Sensitivity Threshold and Pass-Fail Techniques)
Standard Test Method for Compatibility of Materials with Liquid Oxygen (Impact Sensitivity Threshold and Pass-Fail Techniques)
SIGNIFICANCE AND USE
When this test method is used to measure the threshold impact sensitivity of a material, a relative sensitivity assessment is obtained which permits the ranking of materials.
This test method may also be used for acceptance-testing materials for use in liquid oxygen systems. Twenty separate samples of the material submerged in liquid oxygen are subjected to 98 J (72 ft·lbf) or as specified. Impact energy delivered through a 12.7-mm (½-in.) diameter contact. More than one indication of sensitivity is cause for immediate rejection. A single explosion, flash, or other indication of sensitivity during the initial series of 20 tests requires that an additional 40 samples be tested without incident to ensure acceptability of the material.
The threshold values are determined by this test method at ambient pressure. The sensitivity of materials to mechanical impact is known to increase with increasing pressure. Since most liquid oxygen systems operate at pressures above ambient condition, some consideration should be given to increased sensitivity and reactivity of materials at higher pressure when selecting materials for use in pressurized system.
SCOPE
1.1 This method,, covers the determination of compatibility and relative sensitivity of materials with liquid oxygen under impact energy using the Army Ballistic Missile Agency (ABMA)-type impact tester. Materials that are impact-sensitive with liquid oxygen are generally also sensitive to reaction by other forms of energy in the presence of oxygen.
1.2 This standard should be used to measure and describe the properties of materials, products, or assemblies in response to heat and flame under controlled laboratory conditions and should not be used to describe or appraise the fire hazard or fire risk of materials, products, or assemblies under actual fire conditions. However, results of this test may be used as elements of a fire risk assessment which takes into account all of the factors which are pertinent to an assessment of the fire hazard of a particular end use
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.
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Designation:D2512–95 (Reapproved 2002)
Standard Test Method for
Compatibility of Materials with Liquid Oxygen (Impact
Sensitivity Threshold and Pass-Fail Techniques)
This standard is issued under the fixed designation D 2512; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (e) indicates an editorial change since the last revision or reapproval.
This standard has been approved for use by agencies of the Department of Defense.
e NOTE—Adjunct references were corrected editorially in June 2006.
1. Scope C 145 Specification for Solid Load-Bearing Concrete Ma-
, ,
2 3 4 sonry Units
1.1 Thismethod coversthedeterminationofcompatibil-
D 1193 Specification for Reagent Water
ity and relative sensitivity of materials with liquid oxygen
2.2 Military Standards:
under impact energy using the Army Ballistic Missile Agency
MIL-D-16791G Detergent, General Purpose (Liquid, Non-
(ABMA)-typeimpacttester.Materialsthatareimpact-sensitive
ionic)
with liquid oxygen are generally also sensitive to reaction by
MIL-P-27401C Propellant Pressurizing Agent, Nitrogen
other forms of energy in the presence of oxygen.
MIL-PRF-25508F Propellant, Oxygen
1.2 This standard should be used to measure and describe
MIL-T-27602B Trichloroethylene, Oxygen Propellant
the properties of materials, products, or assemblies in response
Compatible
to heat and flame under controlled laboratory conditions and
MIL-C-81302D Cleaning Compound, Solvent, Trichlorotri-
should not be used to describe or appraise the fire hazard or
fluorocarbon
fire risk of materials, products, or assemblies under actual fire
2.3 ASTM Adjuncts:
conditions. However, results of this test may be used as
Type Impact Tester and Anvil Region Assembly, 38 Draw-
elements of a fire risk assessment which takes into account all
ings
of the factors which are pertinent to an assessment of the fire
hazard of a particular end use.
3. Summary of Test Method
1.3 This standard does not purport to address all of the
3.1 A sample of the test material is placed in a specimen
safety concerns, if any, associated with its use. It is the
cup, precooled and covered with liquid oxygen, and placed in
responsibility of the user of this standard to establish appro-
the cup holder located in the anvil region assembly of the
priate safety and health practices and determine the applica-
impact tester. A precooled striker pin is then centered in the
bility of regulatory limitations prior to use.
cup. The plummet is dropped from selected heights onto the
2. Referenced Documents pin, which transmits the energy to the test specimen. Observa-
tion for any reaction is made and the liquid oxygen impact
2.1 ASTM Standards:
sensitivityofthetestmaterialisnoted.Droptestsarecontinued
using a fresh specimen cup and striker pin for each drop, until
This test method is under the jurisdiction of ASTM Committee G04 on
Compatibility and Sensitivity of Materials in Oxygen EnrichedAtmospheres and is
the direct responsibility of Subcommittee G04.01 on Test Methods.
Current edition approved Feb. 15, 1995. Published April 1995. Originally Annual Book of ASTM Standards, Vol 04.05.
e1 6
published as D 2512 – 66. Last previous edition D 2512 – 82 (1994) . Annual Book of ASTM Standards, Vol 11.01.
2 7
“NASA Handbook 8060. 1B, Ambient LOX Mechanical Impact Screening AvailablefromStandardizationDocumentsOrderDesk,Bldg.4SectionD,700
Test,” September 1981, pp. 4-53 through 4-71. “Oxygen Systems.” George C. Robbins Ave., Philadelphia, PA 19111-5098, Attn: NPODS.
Marshall Space Flight Center, National Aeronautics and Space Administration. Cancelled in 1983. Previously available from Standardization Documents
Specification MSFC 106B. September 1981. Order Desk, Bldg. 4 Section D, 700 Robbins Ave., Philadelphia, PA 19111-5098,
“Lubrication and Related Research and Test Method Development forAviation Attn: NPODS.
Propulsion Systems.” Technical Report No. 59-726. Wright Air Development Detailed drawings for the ABMA-Type Impact Tester and Anvil Region
Division, January 1960. Assembly are available from ASTM International Headquarters. Order Adjunct
“General Safety Precautions for Missile Liquid Propellants.” ADJD2512.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
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D2512–95 (2002)
the threshold valve is achieved. A series of drop tests are
conducted at an energy level of 98 J (72 ft·lbf) or as specified
for the pass-fail tests.
4. Significance and Use
4.1 When this test method is used to measure the threshold
impact sensitivity of a material, a relative sensitivity assess-
ment is obtained which permits the ranking of materials.
4.2 This test method may also be used for acceptance-
testing materials for use in liquid oxygen systems. Twenty
separate samples of the material submerged in liquid oxygen
are subjected to 98 J (72 ft·lbf) or as specified. Impact energy
delivered through a 12.7-mm ( ⁄2-in.) diameter contact. More
than one indication of sensitivity is cause for immediate
rejection. A single explosion, flash, or other indication of
sensitivity during the initial series of 20 tests requires that an
additional 40 samples be tested without incident to ensure
acceptability of the material.
4.3 The threshold values are determined by this test method
at ambient pressure. The sensitivity of materials to mechanical
impact is known to increase with increasing pressure. Since
FIG. 2 Schematic Diagram of Power Supply
mostliquidoxygensystemsoperateatpressuresaboveambient
condition, some consideration should be given to increased
sensitivity and reactivity of materials at higher pressure when
5.1.1 Three Guide Tracks, capable of maintaining accurate
selecting materials for use in pressurized system.
vertical alignment under repeated shock conditions.
5.1.2 Plummet, with a weight of 9.072 6 0.023 kg (20 6
5. Apparatus
0.05 lbs).
5.1 ABMA-Type Impact Tester (Fig. 1 , See ADJD2512),
5.1.3 Safety Catch, operated by a solenoid, and designed to
for determining the sensitivity of materials to liquid oxygen
hold the plummet near the base of the magnet. It is used to
with impact energy. Fig. 2 shows the schematic diagram of the
support the plummet in the event of a power failure.
typicalpowersupply.Thetesterconsistsofthefollowingparts:
5.1.4 Electromagnet, for supporting or releasing the plum-
met.Theelectromagnetisdesignedtohold9.072kg(20lbs)of
weight with a minimum amount of electrical energy.
5.1.5 Base—The base of the tester is composed of the
following: a rigid 0.61- by 0.61- by 0.61-m (2- by 2- by 2-ft)
(min)reinforcedconcreteblock(concreteconformingtoSpeci-
fication C 145), a 3.2-mm ( ⁄8-in.) stainless steel sheet, and a
25-mm (1-in.) thick stainless steel base plate. Four stainless
steel foundation bolts protruding from the concrete block are
used to fasten the plate and sheet to the smooth surface of the
concrete block with stainless steel nuts.
NOTE 1—Where not otherwise indicated, stainless steel shall be of the
AISI 300 series.
5.1.6 Anvil Plate (Fig. 3), made from a 51-mm (2-in.) thick
Type 440B heat-treated steel plate, (56 to 58 HRC) that is
centered and rests on the base plate. It in turn centers the
specimen cup holder.
5.1.7 Striker Pin—The striker pins shall be machined from
AMS 5643D stainless steel, heat condition H-900 (Fig. 4).
5.1.8 Striker Pin Guide.
5.1.9 Specimen Cups—One- and two-piece specimen cups
shall be used. The one-piece specimen cup (Fig. 5) shall be
used for liquid and solid test materials. When testing hard
samples that are sometimes capable of initiating reactions with
the aluminum cup, expendable Type 347 stainless steel disks
11 1
17.5 mm ( ⁄16 in.) in diameter by 1.6 mm ( ⁄16 in.) thick shall
be placed in the bottom of the cup. The two-piece cup (Fig. 6)
FIG. 1 ABMA-Type Impact Tester shall be used for testing semisolid materials; a one-piece insert
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D2512–95 (2002)
located in a darkened area. Continuous ventilation shall pro-
vide fresh air to the test cell. Construction of the cell shall be
directedatprovidingafacilitythatcanbemaintainedeconomi-
cally at a high level of good housekeeping. The test cell shall
be cleaned periodically to ensure cleanliness of sample and
equipment.
5.3 Freezing Box, as illustrated in Fig. 8.
5.4 Auxiliary Equipment—The auxiliary equipment shall
consist of forceps for handling the specimen cups and striker
pins,stainlesssteelspatulas,liquidoxygenhandlingequipment
such as stainless steel Dewar flasks, liquid oxygen protective
gloves, lintless laboratory coat, eye protection equipment, and
liquid oxygen storage containers. Special handling equipment
shall include striker pin holders (Fig. 9), specimen cup trays,
covered storage container for specimen cups and striker pins,
and a vapor-phase degreaser. The following items are also
recommended: microburet, control panel with switches to
activate the safety catch and electromagnet, stereomicroscope,
micrometerdepthgagewithlevelingblocks,presspunchcutter
forpreparationofplasticspecimens,oven,andrefrigerator.For
checking surface roughness of striker pins and specimen cups,
a set of visual roughness comparison standards or a surface
FIG. 3 Anvil Region Assembly
roughness measuring instrument shall be required. Timing
instrumentation shall be required to measure the drop time of
the plummet. A suitable free-fall timing circuit is illustrated in
Fig. 10.
6. Reagents and Materials
6.1 Alkaline Cleaner, for striker pins and stainless steel
inserts, consisting of a solution of 15 g of sodium hydroxide
(NaOH), 15 g of trisodium phosphate (Na PO ), and 1 L of
3 4
distilled or deionized water.
6.2 Alkaline Cleaner, for cups; a nonetch-type solution such
as Enthone NE or equivalent shall be used.
6.3 Aqua Regia—Mix 18 parts of concentrated HNO (sp gr
NOTE 1—Break sharp edges approximately 0.015. 1.42) with 82 parts of concentrated hydrochloric acid (HCl, sp
NOTE 2—Machine all surfaces 32 rums except as noted.
gr 1.19) by volume.
NOTE 3—Material: stainless steel AMS 5643 D.
6.4 Deionized Water, conforming to Specification D 1193.
NOTE 4—Heat treatment: H-900 to obtain Rc 43 to 44.
6.5 Detergent, General-Purpose (Liquid, Nonionic), con-
NOTE 5—Finish: electropolish after heat treatment.
forming to MIL-D-16791G.
NOTE 6—Surfaces A and B should be parallel and perpendicular to the
6.6 Hydrofluoric Acid (48.0 to 51.0 %)—Reagent grade
center line within 0.001TIR and 16-32 rms along a radius.
concentrated hydrofluoric acid (HF).
All dimensions in inches.
FIG. 4 Striker Pin 6.7 Liquid Nitrogen, conforming to MIL-P-27401C.
(Warning—Contact with the skin can cause frostbites resem-
bling burns.)
cup (Fig. 7) may also be used. The recess of either of these
6.8 Gaseous Nitrogen, conforming to MIL-P-27401C.
permits use of a 1.27-mm (0.050-in.) thick sample.
(Warning—Compressed gas under high pressure. Always use
5.1.10 Specimen Cup Holder, consisting of a 25-mm (1-in.)
a pressure regulator. Release regulator tension before opening
thick stainless steel block centered on the anvil plate. This
cylinder.)
holder has two protruding spacers which align the striker pin
6.9 Liquid Oxygen, conforming to MIL-PRF-25508F.
guide, and in turn the striker pin, with the nose of the plummet,
(Warning—Oxygen vigorously accelerates combustion. Con-
thus ensuring a direct hit by the nose of the plummet on the
tact with skin can cause frostbite resembling burns.)
striker pin in the specimen cup.
6.10 Nitric Acid (relative density 1.42)—Reagent grade
5.2 Test Cell—The impact tester shall be housed in a test
nitric acid (HNO ).
cell containing a concrete floor. Walls shall be constructed of
reinforced concrete or metal to provide protection from explo-
American National Standard B 46.1-1962. Surface Texture standards may be
sion or fire hazards. The cell shall be provided with a
used.
shatterproof observation window, and shall be darkened suffi-
Available from Enthone, Inc., a division of American Smelting and Refining
ciently to permit observation of flashes. The operator shall be Co., Box 1900, New Haven, CT 06508.
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D2512–95 (2002)
NOTE 1—Break sharp edges 0.015.
NOTE 2—The cup is formed by deep drawing.
NOTE 3—The thickness and parallelness of the cup bottom shall be controllled to 0.0610 to 0.0630 by coining.
NOTE 4—Materal: aluminum alloy QQ-A-318 (5052) temper H32.
All dimensions in inches.
FIG. 5 One-Piece Specimen Cup
6.11 Trichloroethylene, conforming to MIL-T-27602. two persons as a group. Extreme caution shall be exercised in
(Warning—Harmful if inhaled. High concentrations may
preventing contact with oils or other combustible materials.All
cause unconsciousness or death. Contact may cause skin
tools must be degreased before use. Precautions shall be taken
irritation and dermatitis.)
to prevent accumulation of moisture in lines, valves, traps, and
so forth to avert freezing and plugging with subsequent
NOTE 2—The use of trichloroethylene is banned in California by the
pressure ruptures. Care shall also be taken to prevent entrap-
California Air Pollution Board.
ment of liquid oxygen in unvented sections of any system.
6.12 Trichlorotrifluoroethane, conforming to MIL-C-
7.4 Safety shower and other protective equipment shall be
81302D Type I. (Warning—Harmful if inhaled.)
inspected periodically and before each handling of liquid
oxygen. Personnel leaving the working or storage area shall
7. Safety Precautions
take steps to make sure that no oxygen remains absorbed in
7.1 The hazards involved with liquid oxygen are very
clothing before smoking or approaching any source of ignition.
serious. Contact with the skin can cause frostbites resembling
7.5 The threshold limit value, that is, the time-weighed
burns. Contact with hydrocarbons or other fuels causes an
average concentration of trichloroethylene believed safe for
explosion hazard, as such mixtures are usually shock, impact,
continuous exposure during a normal 8-h workday, has been
and vibration-sensitive.
established by the American Conference of Governmental
7.2 The first-aid procedure for liquid oxygen contact is to
Industrial Hygienists at 100 ppm. Operations using trichloro-
flush the affected area with water. This treatment should be
ethylene should always be conducted in a well-ventilated area.
followed by medical attention. A safety shower must be
The comparable figure for trichlorotrifluorethane is 1000 ppm,
available in the immediate area.
and normal ventilation is usually adequate. When a ventilation
7.3 The follow
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