1、.i . MIL-M-27274E m 9999906 1948545 L51 m (INCH-POUND MIL-M-27274EVSAF) 27 AUGUST 1993 SUPERSEDING 20 JUNE 1974 MIL-M-27274DWSAF) MILITARY SPECIFICATION MASK, OXYGEN MBU-SP This specification is approved for use by the Departments of the Air Force and is available for use by all Departments and Agen
2、cies of the Department of Defense. 1. SCOPE 1.1 Scope. This specification covers one type of pressure breathing oxygen mask designated MBU-SP. 1.2 distribution is unlimited. Licensed by Information Handling ServicesMILITARY MIL-C-5040 MIL-T-8363 MIL-O-272 10 MIL-V-27296 STANDARDS FEDERAL FED-STD-595
3、 FED-STD-601 MILITARY MIL-STD-100 MIL-STD-129 MIL-STD- 130 MIL-STD-970 MIL-STD-147 MIL-STD-83 1 MIL-STD-2073 MS22064 MS27796 MS27980 MS27983 Cord, Fibrous, Nylon Tape and Webbing, Textile, Woven, Nylon Oxygen, Aviators Breathing, Liquid and Gas Valve, Oxygen Mask, Combination Inhalation and Exhalati
4、on Colors Rubber, Sampling and Testing Engineering Drawing Practices Marking for Shipment and Storage Identification Marking of U.S. Military Property Standards and Specifications, Order of Precedence for Selection of Palletized Unit Loads Test Reports, Preparation of DOD Material Procedures for Dev
5、elopment and Application of Packaging Clamp, Oxygen Hose Connector-Bayonet, Three Pin, Oxygen Mask Fastener, Snap, Style 2 (Regular Wire Spring) Fastener, Snap, Style 4 Requirements (Unless otherwise indicated, copies of federal and military specifications, standards, and handbooks are available fro
6、m the Standardization Documents Order Desk, Building 4D, 700 Robbins Avenue, Philadelphia, PA 191 11-5094.) 2.1.2 Other Government documents, drawings. and publications. The following other Government documents, drawings and publications form a part of this document to the extent specified herein. U
7、nless otherwise specified, the issues are those cited in the solicitation. Air Force 60D3516 Face Form-Oxygen Mask, Size Short Narrow 60D3519 Face Form-Oxygen Mask, Size Regular Narrow 60D3522 Face Form-Oxygen Mask, Size Long Narrow 60D3525 Face Form-Oxygen Mask, Size Regular Wide 64D 1676 Cover-Dus
8、t, Ml3U-W Oxygen Mask 7425 180 Oxygen Mask-Type MBU-S/P - (A 1) (Application for copies should be addressed to SA-ALCRTILDE, Kelly AFJ3, TX 78241-5000.) 2 Licensed by Information Handling Services2.2 Non-Government Dublications. The following documents form a part of this specification to the extent
9、 specified herein. Unless otherwise indicated, the issues of the documents which are DoD adopted are those listed in the issue of the DODISS cited in the solicitation. Unless otherwise specified, the issues of documents cited in the solicitation not listed in the DODISS are the issues of the documen
10、ts cited in the solicitation (see 6.2). AMERICAN SOCIETY FOR TESTING AND MATERIALS AST“D-624 Tear Resistance of Vulcanized Rubber AST“D-1788 Standard Specification for Rigid Acrylonitrile-Butadiene-Styrene (ABS) Plastics ASTM-D-395 1 Packing, Commercial (Application for copies should be addressed to
11、 the American Society for Testing and Materials, 1916 Race Street, Philadelphia, Pennsylvania 19103). 2.3 Order of precedence. In the event of a conflict between the text of this document and the references cited herein, the text of this document takes precedence. Nothing in this document, however,
12、supersedes applicable laws and regulations unless a specific exemption has been obtained. 3. REQUIREMENTS 3.1 First article. When specified (see 6.2), a sample shall be subjected to first article inspection (see 6.4) in accordance with 4.4. 3.2 Selection of swcifications and standards. Specification
13、s and standards for necessary commodities and services not specified herein shall be selected in accordance with MIL-STD-970. O 3.3 Materials. Materials shall conform to the applicable specifications and shall be as specified herein. Materials which are not covered by specifications, or which are no
14、t specifically described herein, shall be of the best quality, of the lightest practicable weight, and suitable for the purpose intended. Materials that will come in contact with oxygen shall be entirely free from oil, grease, or any other combustible materials. 3.3.1 Silicone material. Silicone rub
15、ber shall be used in the facepiece, the delivery tube, and the microphone cable guides of the oxygen mask and shall conform to Class 3a, Grade 50 of zZ-R-765, except that the minimum brittle point shall be -56OC and the Shore A hardness shall be 45 25. It shall be smooth and free from flash, foreign
16、 materials, or imperfections. The silicone rubber shall be postcured in a well ventilated forced air oven. The date (by year and quarter) the silicone rubber was cured shall be molded on the facepiece and the delivery tube of the mask. 3.3.2 Plastic materials. The hardshell shall be fabricated by in
17、jection molding or forming from acrylonitrile- butadiene-styrene molding plastic conforming to ASTM-D-1788. The color of the hardshell shall be the same as the color of the mask facepiece. The thickness of the hardshell shall be 3/64 5 1/64. 3.3.3 Webbing. The hardshell webbing shall conform to Type
18、 I of MIL-T-8363. The color of the webbing shall be substantially the same as the color of the hardshell. 3.3.4 Nylon cord. The nylon cord shall conform to Type IA of MIL-C-5040. 3.3.5 Protective treatment. When materials that are subject to corrosion in oxygen, salt air, or any other atmospheric co
19、nditions likely to occur during service usage are used in the construction of the mask, they shall be protected against corrosion in the manner that in no way prevents compliance with the performance requirements of this specification. The use of any protective coating that will crack, chip, or scal
20、e with age or extremes of atmospheric conditions shall be avoided. 3 Licensed by Information Handling Services3.4 Design and construction. The design and construction of the mask shall be in accordance with Air Force drawings 60D3516,60D3519,60D3522,60D3525 and 7425180 (see figures 1-9 inclusive). A
21、ir Force drawings 60D3516,60D3519,60D3522, and 60D3525 should be used as general guidelines in the design of tooling. O 3.4.1 pluR. Each mask shall have a suitable leak tight plug for the microphone flange fabricated from metal, plastic, or hard rubber. 3.4.2 Antifreeze chamber. The antifreeze chamb
22、er and the body of the mask shall be of one-piece construction as shown (see figures 4 and 5). A 1/16 inch hole located as shown in figures 4 and 5 shall vent the antifreeze chamber. 3.4.3 Combination valve. A combination inhalationexhalation valve conforming to MIL-V-27296, Type I, shall be inserte
23、d in the mask as shown (see figure 5). 3.4.4 Deliverv tube. The delivery tube for the mask shall be constructed of corrugated silicone as shown (figure 6). The delivery tube shall have one upper cable guide (see figure 7) and located as shown (see figure 1). 3.4.5 ClamD. The delivery tube shall be a
24、ttached to the combination valve by means of a hose clamp conforming to Scott Aviation Division of Figgie, Intl. Inc., Sierra Madre, part number 450-134A or approved equal. Clamp assembly pliers conforming to Scott Aviation, part number 450-801 may be used to attach the clamp. 3.4.6 Connector. A con
25、nector conforming to MS27796 shall be attached to the delivery tube by means of a hose clamp conforming to MS22064-5 or other approved hose clamps. A lower cable guide (see figure 7) shall cover this hose clamp and shall be located as shown (see figure 1). 3.4.7 Limited stretch cord. A nylon cord an
26、d snap assembly as shown (see figure 8) shall be installed inside the delivery tube by attaching a nylon loop to the combination valve retention pin and a metal snap to the O connector retention pin. The snap shall be Pacific Marine Supply Company, Seattle, Washington, size No. 2/0 (1 3/16 inches in
27、 length, 1 IO-pound test). or equal, and shall be attached to one end of the nylon cord as shown (see figure 8). 3.4.8 Hardshell assembly. The hardshell assembly shall consist of the hardshell including the installed hardshell webbing, harness fasteners with screws, and suspension harness restrained
28、. The hardshell assembly shall be as shown (see figures 1 and figure 9). 3.4.8.1 Hardshell. The hardshell for the mask shall closely follow the contour of the outside of the facepiece and shall be designed to assure that all of the performance requirements specified herein are met. The edges of the
29、hardshell nearest the users face shall be flared, and all sharp edges shall be rounded. Dimensions given (see figures 2 and 3) may be used as general guidelines in the design of the hardshell. 3.4.8.2 Hardshell webbing. The webbing shall be riveted to the hardshell as shown (see figure 1) by 1/8 inc
30、h tubular rivets having a minimum head diameter of 9/32 inch. 3.4.8.3 Harness fasteners. Fasteners conforming to MS27980 and MS27983 shall be located in the hardshell as shown (see figure 9). Two machine screws (3-56NF-3A by 0.375 inch long) shall secure the harness assembly to the hardshell. These
31、machine screws shall be provided as part of the hardshell assembly. 3.4.8.4 Suswnsion harness restrainer. A suitable device as shown (see figure I) shall be provided for restricting the lateral movement of the harness assembly when the mask is used with a continuous single strap suspension harness a
32、ssembly. The device shall be provided as a component of the hardshell assembly and shall be approved by the procuring activity. 4 Licensed by Information Handling ServicesMIL-M-27274E 3.4.9 Dust cover. The mask shall be equipped with a dust cover to prevent dust, dirt, and foreign objects from enter
33、ing the mask cavity when the mask is not in use. The cover shall be made of durable, nonbrittle, lightweight plastic material contoured to rest around the face edge of the hardshell and to be retained on the hardshell with an elastic webbing around the front edge of the hardshell at the microphone c
34、ontour. The configuration of the cover shall conform to 64D1676. The cover shall not rest on the face piece contour between the seal area and the body of the facepiece. 3.5 Performance. 3.5.1 Mask leakage. The inboard leakage shall not exceed 100 milliliters per minute when tested (see 4.6.2). 3.5.2
35、 Combination valve installation. inlet performance (low suction). The total leakage through the combination valve inlet portion shall be 15 milliliter per minute or less when tested (see 4.6.3). 3.5.3 Combination valve installation. inlet performance (hkh suction). The total leakage through the comb
36、ination valve inlet portion shall be 150 milliliters per minute or less when tested (see 4.6.4). 3.5.4 Combination valve installation, exhalation performance. A pressure of 20 millimeters of mercury in the facepiece and a pressure between 15 and 19.9 millimeters of mercury in the inlet tubing shall
37、cause the exhalation portion of the valve to open when tested (see 4.6.5). 3.5.5 Combination valve installation. exhalation resistance. The exhalation resistance shall not be greater than 4.67 millimeters of mercury with a flow of 100 liters per minute when tested (see 4.6.6). 3.5.6 Delivew tube lea
38、kage. The delivery tube shall not leak when subjected to an internal air pressure of five pounds per square (see 4.6.7). O 3.5.7 Delivew tube strenHh. The delivery tube shall not tear or separate when tested (see 4.6.8). 3.5.8 Tear resistance. The silicone rubber shall have a minimum tear resistance
39、 of 150 pounds per inch when tested (see 4.6.9). 3.5.9 Hardness. The Shore-A-Durometer hardness of the silicone rubber shall be 45 +S when tested (see 4.6.10). 3.5.10 Toxicity. The silicone rubber shall not contain any chemicals or materials that have toxic properties (see 4.6.11). 3.5.11 Subiective
40、 use. The silicone rubber shall not produce any objectionable odors, shall not be tacky, and shall not have any other properties that cause discomfort or affect wear ability. The mask shall have no detrimental or objectionable performance characteristics when evaluated (see 4.6.12). 3.5.12 Hardshell
41、 flexibility. The mask hardshell shall withstand a decrease in width (as measured by dimension B of figure 2) of 1 1/2 inches without visible cracking or fracture when subjected to compressive loading (see 4.6.13). 3.6 -r. The color of the hardshell, webbing, and all silicone rubber used in the oxyg
42、en mask assembly shall be green, approximately matching color number 34079 conforming to FED-STD-595. 3.7 Interchangeabilitv. All parts having the same manufacturers part number shall be functionally and dimensionally interchangeable. The drawing number requirements of MIL-STD-100 shall govern the m
43、anufacturers part numbers and changes thereto. 5 Licensed by Information Handling Services3.8 Identification of product. The mask assembly shall be marked with the following specific information conforming to MIL-Sm-130. The Federal Stock Number shall be omitted from the nameplate. Mask, Oxygen: MBU
44、-5/P Mask Size: M27274-* Manufacturer: * Date of Manufacture: (Quarter and Year)* 3.8.1 Tubing. The mask end of the tubing shall be identified by molding “Mask End“ into the rubber. The date of manufacture (quarter and year) shall be molded on either end of the tubing. 3.9 Workmanshiu. The mask shal
45、l be constructed in accordance with good commercial practice, and shall be free from any defects which might afect appearance or function. The mask shall be clean and dry, free from oil, grease, and other foreign matter. All metal and plastic parts shall be smooth and free of sharp edges. All excess
46、 flash shall be properly trimmed. The facepiece and its related parts shall be smooth and free from blisters, porous arias, cracks, abrasions, bubbles, and foreign material. 3.10 Reclaimed materials. The use of reclaimed materials shall be encouraged to the maximum extent possible. 4. QUALITY ASSURA
47、NCE PROVISIONS. 4.1 Remnsibilitv for insuection. Unless otherwise specified in the contract or purchase order, the supplier is responsible for the performance of all inspection requirements as specified herein. Except as otherwise specified in the contract or order, the supplier may use his own or a
48、ny other facilities suitable for the performance of the inspection requirements specified herein, unless disapproved by the Government. The Government reserves the . right to perform any of the inspections set forth in the specification where such inspections are deemed necessary to assure supplies
49、and services conform to prescribed requirements. O 4. l. 1 Resuonsibilitv for comuliance. All items shall meet all requirements of sections 3 and 5. The inspection set forth in this specification shall become a part of the contractors overall inspection system or quality program. The absence of any inspection requirements in the specification shall not relieve the contractor of the responsibility of ensuring that all products or supplies submitted to the Government for acceptance comply with all requirements of the contract. Sampling inspection. as part of manufacturing operations, is a
