ASTM F371-83(1994)e1

NOTICE: This standard has either been superceded and replaced by a new version or discontinued.
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e1
Designation: F 371 – 83 (Reapproved 1994)
Standard Test Method for
Compatibility of Materials with Liquid Oxygen (Reaction
Intensity Method)
This standard is issued under the fixed designation F 371; 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.
e NOTE—Section 14 was added editorially in September 1994.
1. Scope cup holder located in the anvil region of the impact tester. The
plummet is dropped from a fixed height of 1100 mm (43.3 in.),
1.1 This test method covers the determination of the relative
for a total of 3 blank drops and 20 test drops, each on a fresh
reactivity of materials with liquid oxygen under impact using
specimen. On each drop, duplicate measurements are made of
the AFAPL impact tester. It is designed to yield an evaluation
the peak pressure of the air shock wave from the impact area.
of the potential fire or explosive hazard of the material in
In addition, notation is made of any flashes, burning or
contact with liquid oxygen under impact energy only, and shall
post-drop evidence of reaction.
not be used to predict such hazard from other forms of energy.
1.2 This standard does not purport to address all of the
NOTE 1—Other modes of operation of impact testers are described in
safety concerns, if any, associated with its use. It is the Test Method D 2540 and Test Method D 2512. The former describes the
“up-and-down” technique for the 50 % point, and the latter the “threshold
responsibility of the user of this standard to establish appro-
technique,” for approximately the 5 % point.
priate safety and health practices and determine the applica-
bility of regulatory limitations prior to use.
4. Apparatus
2. Referenced Documents 4.1 AFAPL Impact Tester:
4.1.1 ABMA-Type Drop-Weight Apparatus (Fig. 1), consist-
2.1 ASTM Standards:
ing of three guide rails capable of maintaining vertical align-
C 145 Specification for Solid Load-Bearing Concrete Ma-
2 ment under repeated shock conditions, a 9.076 0.02-kg (20 6
sonry Units
0.05-lb) plummet weight, a fourth rail which supports an
D 2512 Test Method for Compatibility of Materials with
electromagnet for holding or releasing the plummet, a
Liquid Oxygen (Impact Sensitivity Threshold and Pass-
solenoid-operated safety catch to support the plummet when
Fail Technique)
the magnet is not energized, and a base plate.
D 2540 Test Method for Drop-Weight Sensitivity of Liquid
4.1.2 Foundation—A rigid 0.61 by 0.61 by 0.61-m (2 by 2
Monopropellants
by 2-ft) (minimum) reinforced concrete block conforming to
2.2 Military Standards:
Specification C 145. Four stainless steel foundation bolts
MIL-P-25508E Propellant, Oxygen
protruding from the concrete block are used to fasten the tester
MIL-T-27602B Trichloroethylene, Oxygen Propellant
base plate to the block.
Compatible
4.1.3 Anvil Region Assembly, consisting of an anvil plate, a
MIL-C-81302C Cleaning Compound Solvent Trichlorotrif-
specimen cup holder, and a striker pin guide (Fig. 2).
luoroethane
4.1.4 Striker Pins and Specimens Cups, stainless steel,
3. Summary of Test Method which may be reused (cleaned and refinished, if necessary)
until their dimensions no longer meet the drawing specifica-
3.1 A sample of the material is placed in a specimen cup,
tions (Figs. 3 and 4).
precooled and covered with liquid oxygen, and placed in the
4.1.5 Specimen Cup Sleeves, aluminum, which are pressed
into position, are used only once, and then discarded (Fig. 4).
This test method is under the jurisdiction of ASTM Committee F-7 on
4.1.6 Reaction Intensity Measuring Systems—Two identical
Aerospace and Aircraft and is the direct responsibility of Subcommittee F07.02 on
but independent reaction intensity measuring systems (Fig. 1
Propellant Technology. ASTM Committee D-2 on Petroleum Products and Lubri-
and Fig. 5) are employed for obtaining peak pressure measure-
cants maintains a continued interest in this test method and will make use of it in the
ments in the air shock waves produced by reactions. Each
future.
Current edition approved April 29, 1983. Published August 1983. Originally
system consists of a shock wave probe which serves to capture
published as F 371 – 73. Last previous edition F 371 – 73 (1980).
Annual Book of ASTM Standards, Vol 04.05.
3 5
Annual Book of ASTM Standards, Vol 15.03. Drawings of the AFAPL impact tester will be furnished at nominal cost from
Available from Standardization Documents Order Desk, Bldg. 4 Section D, 700 ASTM Headquarters, 100 Barr Harbor Dr., PO Box C700, West Conshohocken, PA
Robbins Ave., Philadelphia, PA 19111-5094, Attn: NPODS. 19428–2959. Order Adjunct ADJF0371.
Copyright © ASTM, 100 Barr Harbor Drive, West Conshohocken, PA 19428-2959, United States.
NOTICE: This standard has either been superceded and replaced by a new version or discontinued.
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F 371
FIG. 1 AFAPL Impact Tester
a portion of the shock wave and guide it essentially unchanged 4.1.8 Pressure Transducers, two.
to a remote point of measurement, a piezoelectric transducer, a 4.1.9 Low-Noise Cables.
low-noise transducer cable, a charge amplifier, and a peak 4.1.9.1 It is essential that the electronic portion of the
pressure meter for obtaining a voltage reading corresponding to measuring system located in the test cell (the transducers and
the peak pressure of the shock wave. The use of two measuring cables) be fully protected from the effects of violent reactions.
systems, which are located directly opposite each other, allows Such protection is afforded as follows: (1) The transducer shall
a more accurate measurement of directional reactions. The use
of the shock wave probes allows the transducers to be shielded
from the extraneous effects of violent reactions
Kistler Model 606L, available from Kistler Instrument Corp., 8989 Sheridan
Dr., Clarence, NY 14031, or equivalent, has been found satisfactory for this purpose.
4.1.7 Shock Wave Probes, each consisting of a stainless steel
Kistler Model 131M, available from Kistler Instrument Corp., 8989 Sheridan
tube 406 mm (16 in.) long and 44.5 mm (1.75 in.) in inside
Dr., Clarence, N. Y. 14031, or equivalent, has been found satisfactory for this
diameter. purpose.
NOTICE: This standard has either been superceded and replaced by a new version or discontinued.
Contact ASTM International (www.astm.org) for the latest information.
F 371
FIG. 2 Anvil Region Assembly
be mounted with rubber O-rings to reduce the influence of charge amplifier, use a 50-Hz cutoff filter.
vibrations from the impacting plummet. The entire transducer, 4.1.11 Peak Pressure Meters to allow rapid reading of the
except for the diaphragm, shall be enclosed within the mount- shock wave peak pressure. The circuit diagram for this
ing device so that the air shock waves can reach nothing but the instrument is shown in Fig. 6.
diaphragm, and (2) the low-noise cable shall be enclosed in a 4.1.12 Rebound Catcher (Fig. 1) to catch the plummet
rigid metal or PVC tubing since any movement of the cable due after its initial impact since the allowance of secondary impacts
to air shock waves or flying particles will produce extraneous would reduce the control of ignition stimuli.
signals. 4.1.13 Test Cell, for housing the impact tester. The floor
4.1.10 Charge Amplifiers, on the OUTPUT side of the shall be constructed of concrete and the walls of reinforced
Kistler Model 504, available from Kistler Instrument Corp., 8989 Sheridan Dr.,
Kistler Model 544A50, available from Kistler Instrument Corp., 8989 Sheridan
Clarence, N. Y. 14031, or equivalent, has been found satisfactory for this purpose.
Dr., Clarence, N. Y. 14031, or equivalent, has been found satisfactory for this
purpose.
NOTICE: This standard has either been superceded and replaced by a new version or discontinued.
Contact ASTM International (www.astm.org) for the latest information.
F 371
FIG. 3 Striker Pin
concrete or metal to provide protection from explosion or fire specimens. A stainless steel tray with a cover, similar to a
hazards. The cell shall be provided with a shatter-proof hospital surgical tray, may be used. The design and dimensions
observation window and shall be darkened sufficiently to are not critical, except that it must be about 51 mm (2 in.) deep
permit observation of flashes. (The operator shall be located in and large enough to hold about 30 pins and 30 cups with room
a darkened area outside the test cell.) Continuous ventilation to allow easy handling of the pins and cups by means of
shall provide fresh air to the test cell. Construction of the cell forceps. If desired, two smaller freezing trays may be used, one
shall be such that it can be kept thoroughly clean. for the pins and one for the cups. The use of asbestos insulation
4.1.14 Freezing Tray serving as a container for the pre- under and around the sides of the tray or trays will retard liquid
cooling of striker pins and specimen cups containing the test oxygen boiloff. The tray or trays shall be placed on a table in
NOTICE: This standard has either been superceded and replaced by a new version or discontinued.
Contact ASTM International (www.astm.org) for the latest information.
F 371
FIG. 4 Specimen Cup
the test cell in the vicinity of the impact tester such that their 5. Materials
lower surface is level.
5.1 Liquid Oxygen, conforming to MIL-P-25508.
4.1.15 Auxiliary Equipment consisting of stainless steel
5.2 Trichloroethylene, conforming to MIL-T-27602.
forceps for handling the specimen cups and striker pins,
Trichlorotrifluoroethane conforming to MIL-C-81302 may be
stainless steel spatulas, liquid oxygen handling equipment such
used as an alternative.
as stainless steel Dewar flasks, liquid oxygen protective gloves,
5.3 Detergent —Household detergent.
lintless laboratory coat, eye protection equipment, and liquid
5.4 Sulfuric Acid Dichromate—Mix 1 L of concentrated
oxygen storage containers. Special handling equipment shall
sulfuric acid with 35 mL of saturated sodium dichromate
include specimen cup trays, covered storage containers for
solution.
specimens cups and striker pins, and a vapor-phase degreaser.
5.5 Steel Wool, Grade 00.
The following items are also recommended: microburet (10-
5.6 Abrasive Paper—240 grit silicon carbide waterproof
mL), control panel containing all control devices and measur-
abrasive paper.
ing instruments, stereomicroscope, micrometer depth gage
5.7 Miscellaneous Materials include shop towels, lintless
with leveling blocks, press punch cutter for preparation of
tissue, and distilled water.
plastic specimens, oven, and refrigerator. For checking surface
6. Safety Precautions
roughness of striker pins and specimen cups, a set of visual
roughness comparison standards or a surface roughness
6.1 Liquid Oxygen—The hazards involved with liquid oxy-
measuring instrument shall be required. Timing instrumenta-
gen are very serious. Contact with the skin can cause frostbites
tion shall be required to measure the drop time of the plummet
resembling burns. Contact with hydrocarbons or other fuels
to the nearest ⁄10 ms. A suitable timing circuit is illustrated in
causes an explosion hazard, as such mixtures are usually shock,
Fig. 7.
impact, and vibration sensitive.
10 11
ANSI B46.1-1962 on Surface Texture may be used. Tide or equivalent has been found satisfactory for this purpose.
NOTICE: This standard has either been superceded and replaced by a new version or discontinued.
Contact ASTM International (www.astm.org) for the latest information.
F 371
FIG. 5 Reaction Intensity Measuring System
FIG. 6 Circuit Diagram for Peak Pressure Meter
6.1.1 First Aid—The first aid procedure for liquid oxygen be exercised in preventing contact with oils or other combus-
contact is to flush the affected area with water. This treatment ting materials. All tools must be degreased before use. Precau-
should be followed by medical attention. A safety shower must tion shall be taken to prevent accumulation of moisture in lines,
be available in the immediate area. valves, traps, etc., in order to avert freezing and plugging with
6.2 Safety Rules—The following safety rules must be ob- subsequent pressure ruptures. Care shall also be taken to
served. Personnel working with liquid oxygen must be familiar prevent entrapment of liquid oxygen in unvented sections of
with its nature and characteristics. Approved goggles or face any system.
shields, protective clothing, gloves, and boots must be worn 6.3 Safety Equipment—Safety shower and other protective
during handling or transfer. Such operations shall be performed equipment shall be inspected periodically and prior to each
by not less than two persons as a group. Extreme caution shall handling of liquid oxygen. Personnel leaving the working or
NOTICE: This standard has either been superceded and replaced by a new version or discontinued.
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F 371
FIG. 7 Free Fall Timing Circuit
storage area shall take steps to make sure that no oxygen plate, striker pin guide, specimen cup holder, shock wave
remains absorbed in clothing before smoking or approaching probes, transducer mounts, and base plate of the impact tester
any source of ignition. shall be cleaned thoroughly at the start of each test and between
6.4 Ventilation—The threshold limit value, that is, the tests of different materials by using clean shop towels or steel
time-weighted average concentration of trichloroethylene be- wool, or both, and rinsing with fresh trichloroethylene. In
lieved safe for continuous exposure during a normal 8-h addition, the anvil plate, specimen cup holder, striker pin
workday, has been established by the American Conference of guide, and plummet nose shall be similarly cleaned at least
Governmental Industrial Hygienists at 100 ppm. Operations after every tenth test drop. After completion of testing for the
employing trichloroethylene should always be conducted in a day, the impact tester, handling equipment (Dewar flasks and
well-ventilated area. The comparable figure for trichlorotrif- forceps), striker pins and specimen cups used in testing, and
luoroethane is 1000 ppm, and normal ventilation is usually sample prepar
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