1、MIL-D-2q707 53 W 79777Ob 0105177 5 m x- 19-19 IINCH-POUNDI MIL-D-24709(SH) 4 November 1988 MILITARY SPECIFICATION DISTRIBUTED ISOLATION MATERIAL TYPE R-50-21/64 This specification is approved for use by the Naval Sea Systems Command, Department of the Navy, and is available for use by all Department
2、s and Agencies of the Department of Defense. 1. SCOPE 1.1 Scope. This specification covers Navy type R-50-21/64 homogeneous rubber pad for use in machinery and equipment mounts to isolate vibration and attenuate shock. 1.2 Classification. The above-described rubber pad shall be composed of material
3、generally termed distributed isolation material (DIM) and shall be referred to as DIM pad. The numbers and letters in Navy type R-50-21/64 DIM pad shall indicate the following (see 6.2): (a) The letter “R“ denotes the general class of rubber in accordance (b) The number “50“ designates the design lo
4、ad rating in pounds per with ASTM D 1418. square inch (lb/in2) of projected pad area. The 50 lb/in2 measurement is equivalent to 0.345 megapascal (MPa) or 345 kilonewtons per square meter (kN/m2). (c) The second number (21/64) denotes the design parameter, in this case, the nominal DIM pad thickness
5、 in inches (8.3 millimeters (mm) 1 . 2. APPLICABLE DOCUMENTS 2.1 Government documents. 2.1.1 Specifications and standards. The following specifications and standards form a part of this document to the extent specified herein. Unless otherwise specified, the issues of these documents are those liste
6、d in the issue of the Department of Defense Index of Specifications and Standards (DoDISS) and supplement thereto, cited in the solicitation. Beneficial comments (recommendations, additions, deletions) and any pertinent data which may be of use in improving this document should be addressed to: Comm
7、ander, Naval Sea Systems Command, SEA 5523, Department of the Navy, Washington, DC 20362-5101 by using the self-addressed Standardization Document Improvement Proposal (D d of this document or by letter. THIS DOCUMENT CONTAINS 19 PAGES. AMSC N/A FSC 5330 DISTRIBUTION STATEMENT A. Approved for public
8、 release; distribution is unlimited. T+“ 1, T “% -. Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-SPECIFICATIONS FEDERAL PPP-B-601 - Boxes, Wood, Cleated-Plywood, PPP-B-621 - Boxes, Wood, Nailed and Lock-Corner, PPP-B-636 - Boxes, Shipping, Fiberbo
9、ard. PPP-B-640 - Boxes, Fiberboard, Corrugated, Triple-Wall. MILITARY MIL-P-116 - Preservation, Methods of. MIL-L-10547 - Liners, Case, and Sheet, Overwrap; Water-Vaporproof or Waterproof Flexible. STANDARDS FEDERAL FED-STD-601 - Rubber: Sampling and Testing. FED-STD-313 - Material Safety Data, Tran
10、sportation Data and Disposal Data for Hazardous Materials Furnished to Government Activities, MILITARY MIL-STD-129 - Marking for Shipment and Storage. MIL-STD-407 - Visual Inspection Guide for Rubber Molded and standards are available from the Naval Publications and Forms Center, (ATTN: NPODS), 5801
11、 Tabor Avenue, Philadelphia, PA 19120-5099.) 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 so
12、licitation. 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 SOCIETY FOR TESTING AND MATERIALS (ASTM) Set. (DoD adopted) (DoD adopted) Liquids, Oven. (DoD adopted) Density) and Density of Plasti
13、cs by Displacement. (DoD adopted) D 1149 - Standard Test Method for Rubber Deterioration - Surface Ozone Cracking in a Chamber. (DoD adopted) D 1229 - Standard Test Method for Rubber Property - Compression Set at Low Temperatures. (DoD adopted) D 395 - Standard Test Methods for Rubber Property - Com
14、pression D 412 - Standard Test Methods for Rubber Properties in Tension. D 471 - Standard Test Method for Rubber Property - Effects of D 573 - Standard Test Method for Rubber - Deterioration in an Air D 792 - Standard Test Methods for Specific Gravity (Relative Provided by IHSNot for ResaleNo reprod
15、uction or networking permitted without license from IHS-,-,-MIL-D-24709 53 m 3977906 0305399 9 m ASTM (Continued) D 1418 - Standard Practice for Rubber and Rubber Latices - D 2240 - Standard Test Method for Rubber Property - Durometer D 3182 - Standard Practice for Rubber - Materials, Equipment, and
16、 Nomenclature. Hardness. (DoD adopted) Procedures for Mixing Standard Compounds and Preparing Standard Vulcanized Sheets. (DoD adopted) D 3951 - Standard Practice for Commercial Packaging. (DoD adopted) (Application for copies should be addressed to the American Society for Testing and Materials, 19
17、16 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 services.) 2.3 Order of precedence. I
18、n 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. 3. REQUIREMENTS a 3.1 First article. W
19、hen specified (see 6.2), a sample shall be subjected to first article inspection (see 6.4) in accordance with 4.3. 3.2 Material. 3.2.1 Composition. The pads shall be fabricated of oil-resistant compounds utilizing polymerized chloroprene or nitrile rubber as the basic material in accordance with AST
20、M D 1418. The use of any rubber which gives off toxic, offensive, or damaging volatiles at operating temperatures up to 125 degrees Fahrenheit (“F) 52 degrees Celsius (“C) shall be prohibited. No acceptable toxicity requirements exist for temperatures above 125F. 3.2.2 Recovered materials. Unless ot
21、herwise specified herein, all equip- ment, material, and articles incorporated in the products covered by this speci- fication shall be new and may be fabricated using materials produced from recovered materials to the maximum extent practicable without jeopardizing the intended use. The term “recov
22、ered materials“ means materials which have been collected or recovered from solid waste and reprocessed to become a source of raw materials, as opposed to virgin raw materials. None of the above shall be interpreted to mean that the use of used or rebuilt products is allowed under this specification
23、 unless otherwise specifically specified, 3.3 Appearance. Rubber DIM pads shall be free of visual defects in accor- dance with MIL-STD-407 as specified in 4.5.2. 3.3.1 Surface pattern. Unless otherwise specified (see 6.2), the surface pattern shall be at the option of the manufacturer. ; 3 -W Provid
24、ed by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-c 3.4 Dimensions, Dimensions of the pad shall be measured in accordance with FED-STD-601 as specified in 4.5.2.1. Dimensions of surface pattern shall conform to the drawing dimensions with a tolerance of plus
25、 or minus 0,010 inch (0.26 mm) (see 3.7.1). Dimensions and distributions of voids of the surface pattern shall not preclude cutting the DIM pad into annular (machinery-mounting) pads with walls as narrow as 1/2 inch (13 mm), The pads shall have two hardness-proof buttons molded onto opposite edges a
26、nd lying outside the patterned portion of the pad and securely attached to the parent pad by flash or runners. The buttons shall be of nominal 1,25 inches in diameter by 21/64 inch thick (32 by 8.3 mm thick). Unless otherwise specified (see 6.2), the rubber DIM pad shall be 18 by 18 . DIM pads shall
27、 be identified by markings on the shipping containers in accordance with MIL-STD-129 (see 5.3). 3.10 Toxicity, The pads shall have no adverse effect on the health of personnel when properly used for its intended purpose, The pads shall contain no components which produce noxious vapors in such conce
28、ntrations as to be an annoyance to personnel during formulation or use under conditions of adequate ventilation while exercising caution to avoid prolonged contact with the skin and while observing Occupational Safety and Health Administration (OSHA) guidelines. Questions pertaining to the toxic eff
29、ects shall be referred by the contracting activity to the Naval Medical Command (NAVMEDCOM), Washington, DC, who will act as a medical advisor to the contracting activity, 3.10.1 Material safetv data sheet (MSDS). The contracting activity shall be provided a material safety data sheet at the time of
30、 contract award. The MSDS shall be provided in accordance with the requirements of FED-STD-313. The MSDS shall be included with each shipment of the material covered by this specifica- tion (see 6,5). 4. QUALITY ASSURANCE PROVISIONS 4.1 Responsibilitv for inspection. Unless otherwise specified in th
31、e con- tract 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 order, the contractor may use his own or any other facilities suitable for the perf
32、ormance 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 ensure supplies and services conform to prescribed requirem
33、ents. 4.1.1 Resuonsibilitv 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 quality program. The absence of any inspection requirements in the specification sh
34、all 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 the manufacturing operations, is an acceptable practice to ascertain conformance to
35、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 inspection requirements specified herein are classified as follows: (a) First arti
36、cle inspection (see 4.3). (b) Quality conformance inspection (see 4.4). 4.3 First article inspection, First article inspection shall consist of the examination specified in 4.5.2 and tests as specified in 4.5.3 and 4.5.4. Provided by IHSNot for ResaleNo reproduction or networking permitted without l
37、icense from IHS-,-,-MIL-D-24709 53 W 9999906 0105203 7 W 4.3.1 Sampling for first article. The following samples shall be drawn for first article inspection an testing: (a) Three sheets of the rubber stock, 6 by 6 inches by 0.080 2 0.010 inch (150 by 150 by 2 mm) shall be prepared in accordance with
38、 ASTM D 3182. The sheets shall be certified to have been made from the same rubber compound as the rubber pads with an equivalent cure. Grain directionpshall be marked to facilitate tension testing. representative of production under the contractors identifying number and as specified in 3.2. (c) Fo
39、ur compression set buttons having 1.14 2 0.02 inch (29.0 2 0.5 mm) diameters with thicknesses of 0.50 f: 0,02 inch (13.0 2 0.2 mm) prepared in accordance with ASTM D 395. The buttons shall be certified to have been made from the same rubber compound as the rubber pads and to have an equivalent cure.
40、 (b) Three rubber DIM pads with attached hardness-proof buttons 4.3.2 First article examination. Should any of the pads submitted for first article examination or measurement exhibit major or minor defects as specified in 4.5.2 and 4.5.3 or if the pads fail the tests as specified in 4.5.4 this shall
41、 be cause for rejection. 4.4 Oualitv conformance inspection. Quality conformance inspection shall consist of the examination, measurements, and tests as specified in 4.5.2 and table III and shall be performed in the presence of a qualified NAVSEA representative or a representative of the Command or
42、agency concerned. TABLE III. Oualitv conformance tests. Property Properties of rubber stock Tensile strength Ultimate elongation Specific gravity Properties of pads Deflection under load Resonant frequency - Hardness Test procedure 4.5.3.1 4.5.3.1 4.5.6 4.5.4.1 4.5.4.2 4.5.5 4.4.1 m. A lot for quali
43、ty conformance inspection shall consist of all rubber DIM pads produced in one plant under essentially the same conditions and offered for delivery at one time. In each case the number of DIM pads shall be the lot size. 4.5 Procedures for examination, measurements. and tests. 4.5.1 TemDerature of te
44、sts. Unless otherwise specified, every sample shall be conditioned for at least 4 hours at 80 + 9F (26.7 + 5C) before being tested, and the tests shall be performed at this temperature. - Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-. 4.5.2 Visual
45、 and dimensional examination. Each of the rubber DIM pads e submitted for first article inspection (see 4.3.1) or sampled for quality conformance inspection shall be examined for major and minor defects in accordance with MIL-STD-407 to determine conformance to 3.3. Surfaces of the DIM pad shall be
46、classified as location I in accordance with MIL-STD-407 for the purposes of this examination. Bloom of the surface of the pad shall not be considered a defect. 4,5.2.1 The length, width, and thickness of the DIM pad and the dimensions of the surface design shall be measured in accordance with method
47、s 2001, 2011, 2021, 2031, 2121, 2321 and 2361 of FED-STD-601, as applicable. This shall be done to define the surface design on the DIM pad during first article inspection and to determine conformance to 3.4 for quality conformance. During quality conformance measurements, any deviation of the surfa
48、ce design defined for first article (see 3.1), after allowing for the 0.010 inch (0.26 mm) tolerance (see 3.4), shall be regarded as a major defect as shown in table III to determine acceptance or rejection, Any deviation of the length, width, and thickness of the DIM pad from the specified dimensio
49、ns, after allowing for tolerances (see 3.4 and 6.2) shall be regarded as a major defect, 4.5.3 Tests on special rubber samples. The properties of the 0.080 inch (2 mm) thick samples and compression set buttons (see 4.3.1) representing the rubber pads shall be evaluated to determine conformance to the requirements of 3.5. 4.5,3,1 Initial tensile strength and ultimate elongation. The initial tensile strength and ultimate elongation of the rubber stock shall be determined in accor
