1、MIL-V-2729bC m 9999906 L951ir2b 986 MILITARY SPECIFICATION m MIL-V-27296C 28 October 1993 SUPERSEDING 25 July 1983 MIL-V-27296B VALVE, OXYGEN MASK, COMBINATION INHALATION AND EXHALATION This specification is approved for use by all Departments and Agencies of the Department of Defense. 1. SCOPE 1.1
2、Scope. This specification covers a pressure-compensating inhaiation-exhaiation valve, for use with * oxygen mask assemblies MBU-5F and MBU-12F. * 1.2 Classification. Valves shall be of the following types: Type I - Use with MBU-SP oxygen mask assembly. Type II - Use with MBU- 12F oxygen mask assembl
3、y. 2. APPLICABLE DOCUMENTS 2.1 Government documents. 2.1.1 Specifications. standards, and handbooks. The following specifications, standards, and handbooks form a part of this document to the extent specified herein. Unless otherwise specified, the issues of these documents are those listed in the i
4、ssue of the Department of Defense Index of Specifications and Standards (DODISS) and supplement thereto, cited in the solicitation (see 6.2). SPECIFICATIONS FEDERAL BB-A-1034 Compressed Air, Breathing BB-N-4 1 1 Nitrogen, Technical Beneficial comments (recommendations, additions, deletions) and any
5、pertinent data which may be of use in improving this document should be addressed to: Technology distribution is unlimited. Licensed by Information Handling ServicesMILITARY MIL-U-2729bC W 9999Ob 1951427 1512 W MIGV-27296C I MIL-P-116 Preservation Methods of MIL-A-8625 MIL-M-26542/3 Microphone, M-1
6、OO/AIC MIL-M-26542/12 Microphone, M-I69/AIC MIL-0-272 10 MIL-M-27274 Mask, Oxygen, MBU-SP MIL-M-87 163 Mask, Oxygen, MBU-l2/P Anodic Coatings, for Aluminum and Aluminum Alloys Oxygen, Aviators Breathing, Liquid and Gas el STANDARDS FEDERAL FED-STD-595 Color (Requirements for individual color chips,
7、3 x 5 supplements should be submitted to the Standardization Documents Order Desk, Building 4D, 700 Robbins Avenue, Philadelphia, PA 191 11-5094 citing FED-STD-595 together with appropriate chip number as shown therein.) MILITARY MIL-STD- 1 O0 MIL-STD-129 MIL-STD-130 MIL-STD-781 MIL-STD-83 1 MIL-STD
8、 -8 89 MIL-STD-970 MIL-STD-2073-1 Engineering Drawing Practices Marking for Shipment Storage Identification Marking of U.S. Military Property Reliability Testing for Engineering Development, Qualification and Production Test Reports, Preparation of Dissimilar Metals Standards and Specifications, Ord
9、er of Precedence for the Selection of. DOD Materiel Procedures for Development and Application of Packaging Requirements. (Unless otherwise indicated, copies of federal and military specifications, standards, and handbooks are available from the Standardization Documents Order Desk, Building 4D, 700
10、 Robbins Avenue, Philadelphia, PA 19111-5094.) 2.2 Non-Government publications. The following documents form a part of this document to the extent specified herein. Unless otherwise specified, the issues of the documents which are DOD adopted are those listed in the issue of the DODISS cited in the
11、solicitation. Unless otherwise specified, the issues of documents not listed in the DODISS are the issues of the documents cited in the solicitation (see 6.2). AMERICAN NATIONAL STANDARDS INSTITUTE, INC. ANSI B46.1 Surface Texture (Surface Roughness, Waviness and Lay). (Application for copies should
12、 be addressed to the American National Standards Institute, Inc., 1430 Broadway, New York, New York 10018.) (Non-Government standards and other publications are normally available from the organization that prepare or distribute the documents. These documents also may be available in or through libr
13、aries or other informational services.) 2 Licensed by Information Handling ServicesMIL-V-2729bC m 9999906 1951428 759 m MILV-27296C 2.3 Order of mecedence. In the event of a conflict between the text of this document and the references cited herein (except for related associated detail specification
14、s, specification sheets, or MS standards), the text of this document takes precedence. Nothing in this document, however, supersedes applicable laws and regulations unless a specific exemption has been obtained. 3. REQUIREMENTS 3.1 Qualification. The combination inhalation and exhalation oxygen mask
15、 valve furnished under this specification shall be products which are authorized by the qualijing activity for listing on the applicable qualified products list at the time of award of contract (see 4.4 and 6.3). 3.2 Selections of specifications and standards. Specifications and standards for necess
16、ary commodities and services not specified herein shall be selected in accordance with MIL-STD-970. 3.3 Materials. Materials shall be as specified herein. When materials are used which are not specifically designated, they shall be of the best quality and entirely suitable for the purpose intended.
17、Unless otherwise specified by the procuring activity, all materials and all component parts used in the valve shall have been manufactured not more than 12 months prior to the date of delivexy of the valves. 3.3.1 Nonmetallic materials. Any nonmetallic material that is easily deteriorated or otherwi
18、se adversely affected by continued service use with oxygen shall not be used. Whenever diaphragms or flappers are used in the construction of the type I valve, they shall be made of a silicone rubber. Diaphragms, flappers and the sealing and isolation washers for the type II valves shall be made of
19、a silicone-type rubber. All silicone-type rubber must be acceptable to the procuring activity. 3.3.2 Dissimilar metals. Unless suitable protected against electrolytic corrosion, dissimilar metals shall not be used in intimate contact with each other. Dissimilar metais are defined in MIL-STD-889. 3.3
20、.3 Aluminum or aluminum alloys. Aluminum and aluminum alloys, when used, shall be anodized black in accordance with MIL-A-8625, type II. 3.3.4 Protective treatment. When materials are used in the construction of the valve that are subject to corrosion in oxygen, salt, air, or other atmospheric condi
21、tions likely to occur during service usage, they shall be protected against such corrosion in a manner that will in no way prevent compliance with the performance requirements of this specification. The use of any protective coating that will crack, chip, or scale with age of extremes of atmospheric
22、 conditions shall be avoided. 3.3.5 Corrosion-resistant. All metals parts shall be of the corrosion-resistant type or suitably treated to resist corrosion. Brass, bronze, phosphor bronze, 18-8 corrosion-resistant steel, and anodized aluminum alloy are considered satisfactory corrosion-resistant mate
23、rials. 3.3.6 Silicone rubber. All silicone rubber used in the valves shall be smooth and free from flash, foreign materials, imperfections, and objectionable odors. 3.3.7 Toxicity. The material used in the valves shall not contain any chemicals or materials that have toxic properties as a result of
24、being cleaned with 70-percent isopropyl alcohol solution. 3.4 Desim. The valves shall be as defined by figure 1 and shall conform to the envelope dimensions shown in figure 2. They shall each consist of a valve body, a cap conforming to figure 3, and bearing and sealing washers as described for each
25、 type valve in figures 4 and 5. The valves shall be designed to control the oxygen pressure within a mask and to respond automatically to changes in the regulator. The valves shall be mounted in the expiratory chamber of pressure breathing type masks and shall form a leak tight fit in the exhalation
26、 port. Additionally, care shall be taken in the type I valve design to assure that the exhalation ports on the valve shall not become blocked by the inner walls of the masks rubber anti-icing boot. The valves shall embody the design 3 Licensed by Information Handling ServicesMILV-27296C principles o
27、f pressure compensation and damping. The inhalation-exhalation device of figure 2 shall be considered as a typical method of design. Any deviations in envelope or critical interface dimensions from figures 2, 3,4 and 5 may, at the option of the procuring activity, require the contractor to install t
28、he valve in all sizes of the appropriate type oxygen mask assembly as described in MIL-M-27274 and MIL-M-87163. The contractor will then be required to demonstrate to the procuring activity, the ability of the valve to meet the requirements of the following performance tests as per MIL-M-27274 and M
29、IL-M-87163: Mask Leakage Combination Valve Installation, Inlet Performance Combination Valve Installation, Exhalation Performance Combination Valve Insidlation, Exhalation Resistance 3.4.1 Valve sticking. The exhalation valves may have a tendency to stick in the closed position if there is a suffici
30、ent buildup of sticky residue on the exhalation valve seat, the valves shall be so designed that the valve seat can be cleaned by first removing the valve cap and then swabbing the valve scat with a cotton-tipped swab saturated with a warm diluted solution of a mild detergent and water followed by a
31、 rinse with distilled water. 3.4.2 Inadvertent oxygen remlator shut-off protection. The design of the valves shall includc a feature which shall provide protection during inadvertent oxygen regulator shut-off. This feature shall prevent the breathing of ambient air through the valve. * 3.4.3 Reliabi
32、litv. The valves shall have specified mean cycles between failures (MCBF) of not less than 180,000 cycles at the 90 percent lower confidence limit (see 4.6.22) (This equivalent to a minimum acceptable MCBF of 120,000 cycles and a reliability of 0.9775 for a I0-hour, 9,000 cycle mission.) * 3.5 Const
33、ruction. The valves shall withstand the strains, jars, vibration, and other conditions incident to shipping, storage installation, and service. There shall be no undue flutter or vibration of the valves under service conditions. The valves shall be so constructed that they cannot be disassembled wit
34、hout visible evidence, since it is intended to replace the entire valve instead of permitting repairs when failure occurs. If threads are used in the assembly of the body of the valves, the threads shall be sealed by a method approved by the procuring activity. 3.6 Performance. * 3.6.1 Dumping. The
35、differential pressure shall not fall below O. 1 inch of water (gauge) with a regulator pressure of 0.5 to 14 inches of water (gauge) and an increase of flow from 1.0 to 150 liters per minute (see 4.6.2). 3.6.2 Leakage - suction. Leakage of the valves shall not exceed O. 1 liter per minute when the v
36、alve is subjected to the leakage-suction test (4.6.3). * 15 milliliters per minute with a suction of O. 1 inch of water (gauge) (see 4.6.4). 3.6.3 Leakage - suction. low inlet valve. Back leakage through the inlet check valve shall be not more than * 3.6.4 Inhalation resistance. The inhalation resis
37、tance of the valve shall not exceed 0.75 inch of water (gauge) at a flow of 50 liters per minute and shall not exceed 1.50 inches of water (gauge) at a flow of 100 liters per minute (see 4.6.5). * minute at a pressure of 0.5 to 14 inches of water (gauge) (4.6.6). 3.6.5 Leakage - pressure. Leakage sh
38、all not exceed 0.1 liter per minute with a flow of 1.0 to 50 liters per * flows in the range of O. 1 to 50 liters per minute (see 4.6.7). 3.6.6 Exhalation resistance. Differential pressure shall be between 0.1 and 1.5 inches of water (gauge) with 4 Licensed by Information Handling Services.c . MIL-V
39、-2729bC 9999906 3953430 307 MIL-V-27296C * of water (gauge) with a flow in the range of O. 1 and 50 liters per minute and a pressure within the range of 0.5 to 14 inches of water (gauge) (see 4.6.8). 3.6.7 Exhalation resistance - uressure breathing. The differential pressure shall be between O. 1 an
40、d 1.5 inches * water (gauge) is applied to both sides of the valve (4.6.9). 3.6.8 Overload. The valve shall not leak in excess of 1.0 liter per minute when a pressure of 20 inches of * 3.6.9 Cauacitv. The differential pressure shall not exceed 2.6 inches of water (gauge) with a regulator pressure of
41、 0.5 to 14 inches of water (gauge) and a water flow increasing through the range of 10 to 100 liters per minute (see 4.6.10). * milliliters per minute with a suction of 20 inches of water (gauge) (see 4.6.11). 3.6.10 Leakage - suction. high inlet valve. Back leakage through the valve shall be not mo
42、re than 150 3.6.11 High and low temwrature owration. The valve shall be capable of satisfactory operation at temperature of +160“F and -40F (see 4.6.12). * rupture (see 4.6.13). 3.6.12 Burst messure. The valve diaphragm shall be capable of withstanding a pressure of 5 PSIG without 3.6.13 Low temwrat
43、ure storage and vibration. The valve shall be capable of satisfactory operation after vibration at -65F and exposure to -85F (see 4.6.14). 3.6.14 Orientation. The valve shall be capable of satisfactory operation with the reference axis of the valve in the horizontal position (see 4.6.15). * from zer
44、o to 32,000 feet (see 4.6.16). 3.6.15 Effects on communication. The valve shall not adversely aect speech communication at any altitude 3.6.16 Acceleration unseating of exhalation valve. The exhalation valve shall not be unseated when the combination valve is subjected to accelerations up to nine ti
45、mes the force of gravity (see 4.6.17). * 3.6.17 Suction unseating of exhalation valve. Back leakage through the exhalation valve shall be not more than 100 milliliters per minute when a suction of 10 inches of water (gauge) at the regulator end and a suction of 5. inches of water (gauge) at the mask
46、 end of the valve are applied simultaneously (see 4.6.18). * MBU-12P oxygen mask conforming to MIL-M-87163, as applicable, and used by human subjects, the valve shall not have any detrimental or objectionable performance characteristics at altitudes from ground level to 50,000 feet, at temperatures
47、from -40F to +118F, or any combinations of such altitude and temperature. The valve shall also operate properly at 3,4, 5,6, 7, 8 and 9 times the force of gravity when the subject is performing an anti-g straining maneuver (see 4.6.19). 3.6.18 Subjective use. When installed in a type MBU-SP oxygen m
48、ask conforming to MIL-M-27274 or an * the one shown on figure 2. The valve body and cap shall not be damaged or pulled free, and the restraint cable retention pin shall not be pulled free from its anchor point when tested as specified (see 4.6.20). 3.6.19 Restraint cable retention pin strength. The
49、valve shall have a restraint cable retention pin similar to * cap shall not fail or be separated when tested as specified (see 4.6.21). 3.6.20 Valve installation strennth. This test only applies to the MBU-12P oxygen mask. The valve body and 5 Licensed by Information Handling ServicesMIL-V-2729bC 9999906 L95L43L 243 m MILV-27296C * 3.6.21 Exhalation mechanism leakage. The valve shall be designed such that no portion of the exhalation mechanism will stick in the open position and allow leakage of the ambient air into the breathing air. This is of most concern when the valve is in a
