1、MIL-G-24748A W 9999906 1975924 083 INCH-POUND MIL-G-24748A(SH) 12 January 1994 SUPERSEDING (See 6.5) MILITARY SPECIFICATION GASKETS, METALLIC AND RUBBER, FOR USE IN UNION PIPE FITTINGS 1/4 TO 2-INCH NPS WITH VARIOUS FLUIDS FROM -30 OF (-34 OC) TO 400 OF (204 OC) I This specijkation is approved for u
2、se by the Naval Sea Systems Command, Department of the Navy, and is available for we by all departments and agencies of the Department of Defense. 1. SCOPE 1.1 Scope. This specification covers gaskets, metallic and rubber, consisting of a nitrile or ethylene-propylene rubber inner ring attached to a
3、 copper-alloy cast outer metallic ring for use as a static seal in union connections of piping systems in air, water, steam, and petroleum products. 1.2 Classification. Gaskets shall be of the following types, categorized by the rubber I portion of the gasket (see 3.2.2), as specified (see 6.2). a.
4、Type A - NBR (Nitrile rubber) inner ring b. Type B - EPM (Ethylene-propylene rubber) inner ring 1.2.1 Sizes. Gaskets shall conform to the dimensions shown in 3.3.1 for the specified I nominal size required (see 6.2). 2. APPLICABLE DOCUMENTS 2.1 Government documents. 2.1.1 Specifications, standards,
5、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 issue of the Department of Defense Index of Specifications and Standards (DODISS) and s
6、upplement thereto, cited in the solicitation (see 6.2). Beneficial comments (recommendations, additions, deletions) and any pertinent data which may be of use in improving this document should be addressed to: Commander, SEA 03R42, Naval Sea Systems Command, 253 1 Jefferson Davis Hwy, Arlington, VA
7、22242-5 160 by using the self-addressed Standardization Document Improvement Proposal (DD Form 1426) appearing at the end of this document or by letter. I AMSC N/A FSC 5330 DISTRIBUTION STATEMENT A. Approved for public release, distribution is unlimited. O Provided by IHSNot for ResaleNo reproductio
8、n or networking permitted without license from IHS-,-,-MIL-G-24748A = 9Ob 1975925 TIT = MIL-G-24748A(SH) 4 SPECIFICATIONS FEDERAL QQ-C-390 Copper Alloy Castings (Including Cast Bar) MILITARY MIL-F- 1 183 Fittings, Pipe, Cast Bronze, Silver-Brazing, General Specification for I MIL-P-4861 Packing, Pre
9、formed, Rubber : Packaging of I for Ultrasonic Inspection MIL-F-24227 Fittings and Flanges, Cast Bronze, Silver Brazing, Suitable STANDARDS MILITARY MIL-STD-289 Visual Inspection Guide for Rubber Sheet Material MIL-STD-298 Visual Inspection Guide for Rubber Extruded Goods I (Unless otherwise indicat
10、ed, copies of federal and military specifications and standards are available from the Standardization Documents Order Desk, Bldg. 4D, 700 Robbins Avenue, Philadelphia, PA 191 11-5094.) The following document(s) form a part of this document to the extent specified herein. Unless otherwise specified,
11、 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 not listed in the DODISS are the issues of the documents cited in the solicitation (see 6.2). 2.2 Non-Government publications.
12、 AMERICAN SOCIETY FOR TESTING AND MATERIALS (ASTM) B 61 Standard Specification for Steam or Valve Bronze Castings; (DOD adopted) Standard Specification for Composition Bronze or Ounce Metal Castings; (DOD adopted) B 62 D 395 Standard Test Methods for Rubber Property - Compression Set; (DOD adopted)
13、2 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-G-24748A 9999906 L97592b 956 D 412 Standard Test Methods for Rubber Properties in Tension; (DOD adopted) D 471 Standard Test Method for Rubber Property - Effect of Liquids; (DOD adopted) D 573 Sta
14、ndard Test Method for Rubber - Deterioration In An Air Oven; (DOD adopted) D 2240 Standard Test Method for Rubber Property - Durometer Hardness; (DOD adopted) E 145 Standard Specification for Gravity-Convection and Forced- Ventilation Ovens (Application for copies should be addressed to the American
15、 Society for Testing and Materials, 1916 Race Street, Philadelphia, PA 19103.) (Non-Government standards and other publications are normally available from the organizations that prepare or distribute the documents. These documents also may be available in or through libraries or other informational
16、 services.) 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, supersedes applicable laws and regulations unless a specific exemption has been obtained.
17、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 4.3, prior to delivery of any gaskets. 3.2 Materials. 3.2.1 Metallic outer ring. Material for the metallic outer rings for classification types A or B sha
18、ll be in accordance with Unified Numbering System (UNS) numbers C83600, (290300, or C92200. Typical specifications for these materials include, but are not limited to, ASTM B 61, ASTM B 62, or QQ-C-390. Powdered metal processes are permitted. 3 Provided by IHSNot for ResaleNo reproduction or network
19、ing permitted without license from IHS-,-,- MIL-G-24748A 9999906 1975927 892 3.2.2 Rubber inner ring. Rubber used for the inner ring of each gasket classification type shall conform to 3.2.2.1 and 3.2.2.2. For Type B gaskets the rubber shall be a compound using an ethy lene-propylene polymer, either
20、 ethy lene-propylene copolymer or eth y lene-propy lene-diene terpolymer, which will meet the requirements herein. 3.2.2.1 Temperature range. Each gasket type shall be suitable for continuous use in the I I temperature range indicated below (see 6.1): - -30 degrees Fahrenheit (OF) (-34 degrees Celsi
21、us (OC) to 250 OF (121 OC) Type A -30 OF (-34 OC) to 400 OF (204 OC) (Steam) or to 300 OF (149 OC) (air) 3.2.2.2 Physical properties. The rubber portion of each gasket type shall conform to the physical properties of table I. Physical properties shall be determined as specified (see 4.3.1). - Type 3
22、 I I TABLE I. Physical properties. Property and condition Original: Tensile strength, min, Ib/in2 (MPa) Ultimate elongation, min., percent Durometer hardness (h), f5 points Heat resistance: 70h at 212 OF (100 OC) Change in tensile strength, percent Change in ultimate elongation, max percent Change i
23、n durometer hardness, points Compression set: Method B, max, percent 22h at 158 OF (70 OC) Water resistance: 70h at 212 OF (100 OC) Change in hardness points Change in volume, percent Limii Type A 2031 (14) 250 70 - + 30 f 15 -50 25 f 10 f 15 (Table I Continued on Following Page) ions Type B 1500 (1
24、0.3) 150 75 15 -30 f 10 25 - f5 4 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-G-24748A = 9999906 1975928 729 M MIL-G-24748A(SH) TABLE I. Physical properties - Continued. Property and condition Fluid resistance: Fuel A: 70h at 73 OF (23 OC) Ch
25、ange in tensile strength, max percent Change in ultimate elongation, max, percent Change in durometer hardness, points Change in volume, percent Fuel B: 70h at 73 OF (23 “C) Change in tensile strength, max, percent Change in ultimatv elongation, max, percent Change in durometer hardness, points Chan
26、ge in volume, percent No. 1 Oil: 70h at 212 OF (100 OC) Change in tensile strength, max, percent Change in ultimate elongation, max, percent Change in durometer hardness, points Change in volume, percent No. 3 Oil: 70h at 212 OF (i00 OC) Change in tensile strength, max, percent Change in ultimate el
27、ongation, max, percent Change in durometer hardness, points Change in volume, percent Steam resisfance: 70h at 400 OF (204 OC) Change in tensile strength, max, percent Change in ultimate elongation, max, percent Change in durometer hardness, points Change in volume, percent Change in compression set
28、, max, percent - Limit Type A -25 -25 f 10 -5 to +10 -60 -60 O to -30 O to +40 -25 -45 -5 to +10 -10 to +5 -45 -45 -10 to +5 O to +25 ions Type B -50 -40 +5 O to 15 50 3.2.3 Rubber-to-metal adhesives. Adhesives used to attach the inner rubber ring to the outer metallic ring, if any, shall be selecte
29、d for compatibility with the materials of the specific gasket and shall be properly cured. 3.2.4 Recovered materiais. Unless otherwise specified herein, all material incorporated in the products covered by this specification shall be new and may be fabricated using materiais produced from recovered
30、materials to the maximum extent practicable without jeopardizing the intended use. The term “recovered materials“ means materials which have been collected or recovered from solid waste and reprocessed to become a source of raw materials, as opposed 5 Provided by IHSNot for ResaleNo reproduction or
31、networking permitted without license from IHS-,-,-M1L-G-24748A m 9999906 1975927 bb5 m MI L-G-24748A( S H) to virgin raw materials. None of the above shall be interpreted to mean that the use of used products is allowed under this specification unless otherwise specifically specified. 3.3 Design and
32、 fabrication requirements. 3.3.1 Designs. Gaskets shall be designed for use with standard union fittings for the specified nominal pipe size and conform to the basic dimensional requirements of table II. The cross-section for the rubber portion of the gasket may be circular or elliptical. Metallic P
33、ortion OD AD B (+0.005) (f 1/64) (k0.005) 1 .O08 13/16 0.050 1.184 15/16 0.050 I. 394 1-3/16 0.050 1.715 1-112 0.060 2.045 1-3/4 0.070 2.471 2-1116 0.070 2.791 2-318 0.070 3.391 3 0.090 TABLE II. Gusket dimensions. Rubber portion ID C 0.676 0.009 0.072/0.100 0.801 i 0.009 0.072/0.100 1.051 0.010 0.0
34、7210.100 1.299 * 0.012 0.100/0.120 1.549 0.015 0.100/0.130 1.862 * 0.015 0.100/0.130 2.175 f 0.017 0.100/0.130 2.734 f 0.024 0.13510.160 Nominal pipe size 0.250 0.375 0.500 0.750 1 .o00 1.250 1.500 2.000 NOTES: 1. Dimensions are in inches 2. Surface finish (exposed surfaces) shall be 70 roughness av
35、erage (RA) or smoother 3. Break sharp edges. 6 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-G-2474A m 777790b 1775730 387 m 3.3.2 Fabrication. The rubber inner ring shall be molded in place within or onto the metallic outer ring utilizing a co
36、vulcanization chemical bond during the molding process. I 3.4 Identification. All gaskets shall be individually packaged and each package shall have the following information printed on the outside (see 5.1): a. National stock number b. Nomenclature (gasket, metallic and rubber: size-nps, c. Specifi
37、cation number d. Manufacturers nameltrademark e. Manufacturers rubber compound number f. Manufacturers batch number (see 6.6.1) g. Contract date h. Rubber cure date (see 6.6.2) i. Shelf life (see 6.6.3). j. Part or identifying number (see 6.8). rubber material - - specify NBR or EPM) 4. QUALITY ASSU
38、RANCE PROVISIONS 4.1 Responsibility for inspection. Unless otherwise specified in the contract or purchase order, the contractor is responsible for the performance of all inspection requirements (examinations and tests) as specified herein. Except as otherwise specified in the contract or purchase o
39、rder, the contractor may use his own or any 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 a
40、re deemed necessary to ensure supplies and services conform to prescribed requirements. 4.1.1 Responsibility for compliance. 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 q
41、uality 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 th
42、e manufacturing operations, is an acceptable practice to ascertain conformance to requirements, however, this does not authorize submission of known defective material, either indicated or actual, nor does it commit the Government to accept defective material. 4.2 Classification of inspections. The
43、inspection requirements specified herein are classified as follows: a. First article inspection (see 4.3) b. Quality conformance inspection (see 4.4). 7 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-G-24748A m 9999906 3975733 213 m 4.3 First ar
44、ticle inspection. First article inspection shall include base material tests specified in 4.3.1 and final product tests specified in 4.3.2 (see 6.3 and appendix). The base material tests shall be performed once for each of the base materials used for the gasket construction to demonstrate acceptabil
45、ity of the base materials to the requirements of 3.2. The I final product tests shall be performed for each size range, and type of gaskets supplied to demonstrate suitability of the finished product for its intended use. All tests and inspections shall be performed on sample units produced with equ
46、ipment and procedures normally used in production. 4.3.1 Base material tests. 4.3.1.1 Sampling for base material tests. Sufficient test coupons, plugs, finished gaskets, and so forth, of the required shape and size shall be provided for performance of the tests specified in 4.3.1.2 and 4.3.1.3. 4.3.
47、1.2 Metallic outer ring material. The metal shall be tested for conformance to the chemical and mechanical properties specified in the material specification used (see appendix). 4.3.1.3 Rubber inner ring material. The rubber shall be tested by each of the methods I enumerated in 4.3.1.4 for conform
48、ance to the physical properties identified therein. 4.3.1.4 Physical properties. The rubber portion of each gasket type shall conform to the physical properties of table I. Physical properties shall be determined in accordance with the test methods for rubber products as follows: Property Test metho
49、d Tensile strength Ultimate elongation Durometer hardness - Heat resistance Compression set Water resistance Fluid resistance (type I) Steam resistance (type II) ASTM D 412, die C ASTM D 412, die C ASTM D 2240 ASTM D 573 ASTM D 395 ASTM D 471, distilled water ASTM D 471 4.3.1.4.1 4.3.1.4.1 Steam resistance test. Test shall be performed in accordance with ASTM D 573 with the following supplemental requirements: a. Test oven. Type
