1、MIL-P-2439bA m 9999906 I1973459 TO3 = 28 February 1994 SUPERSEDING 15 September 1970 MIL-P-24396(SHIPS) MILITARY SPECIFICATION PACKING MATERIAL, BRAIDED PTFE (POLYTETRAFLUOROETHYLENE) This specification is approved for use by the Naval Sea Systems Command, Department of the Navy, and is available fo
2、r use by all Departments and Agencies of the Department of Defense. 1. SCOPE 1.1 Scove. This specification covers three types of braided polytetra- fluoroethylene (PTFE) yarn packing impregnated with PTFE dispersion. All types of packing are for service on Naval ships when stuffing box temperatures
3、are limited to a maximum of 450 degrees Fahrenheit (OF). 1.2 Classification. The material is of the following types, as specified (see 6.2). Type A - PTFE braided yarn packing impregnated with PTFE dispersion and Type B - PTFE braided yarn packing impregnated with PTFE dispersion and Type C - PTFE b
4、raided yarn packing impregnated with PTFE dispersion and containing a heat resistant, inert lubricant. containing no lubricant. containing no lubricant but which has been heat cleansed for oxygen service. Beneficial comments (recommendations, additions, deletions) and any pertinent data which may be
5、 of use in improving this document should be addressed to: Commander, Naval Sea Systems Command, SEA 03R42, 2531 National Center Building 3 Washington, DC 20362-5160 by using the self-addressed Standardization Document Improvement Proposal (DD Form 1426) appearing at the end of this document or by l
6、etter. AMSC N/A FSC 5330 DISTRIBUTION STATEMENT A. Approved for public release; distribution is unlimited. Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-P-2439bA m 9999906 1973460 725 m MIL-P-24396A(SH) 2. APPLICABLE DOCUMENTS 2.1 Government do
7、cuments. 2.1.1 Specifications. standards. and handbooks. The following specifi- cations, 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
8、 Specifications and Standards (DODISS) and supplement thereto, cited in the solicitation (see 6.2). SPECIFICATIONS FEDERAL QQ-A-1876 - Aluminum Foil. PPP-F- 320 - Fiberboard; Corrugated and Solid, Sheet Stock (Container Grade), and Cut Shapes. MILITARY MIL-B- 121 - Barrier Material, Greaseproofed, W
9、aterproofed, MIL-P-17667 - Paper, Wrapping, Chemically Neutral (Non- MIL-L-19140 - Lumber and Plywood, Fire-Retardant Treated. Flexible. Corrosive). STANDARDS FEDERAL FED-STD-191 - Textile Test Methods. MILITARY MIL-STD-2073-1 - DOD Materiel Procedures for Development and Appli- cation of Packaging
10、Requirements. (Unless otherwise indicated, copies of federal and military specifications, standards, and handbooks are available from the Standardization Documents Order Desk, BLDG. 4D, 700 Robbins Avenue, Philadelphia, PA 19111-5094.) 2.2 Non-Government publications. The following document(s) form
11、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 solicitation. Unless otherwise specified, the issues of documents not listed in the DODISS are the issues of
12、the documents cited in the solicitation (see 6.2). AMERICAN SOCIETY FOR TESTING AND MATERIALS (ASTM) D 792 - Standard Test Methods for Specific Gravity and Density of D 1457 - Standard Specification for Polytetrafluoroethylene (PTFE) D 2257 - Standard Test Method for Extractable Matter in Textiles.
13、D 3951 - Standard Practice for Commercial Packaging. (DoD adopted) Plastics By Displacement. Molding and Extrusion Materials. (DoD adopted) 2 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-P-ZLi39bA m 9999906 l73Libl bbl m MIL-P-24396A(SH) (Appl
14、ication for copies should be addressed to the American Society for Testing and Materials, 1916 Race Street, Philadelphia, PA 19103.) (Non-Goverment standards and other publications are normally available from the organizations that prepare or distribute the documents. These documents also may be ava
15、ilable in or through libraries or other informational services.) 2.3 Order of precedence. In the event of a conflict between the text of this document and the references cited herein (except for related associated detail specifications, specifications, specification sheets or MS standards), the text
16、 of this document takes precedence. supersedes applicable laws and regulations unless a specific exemption has been obtained. Nothing in this document, however, 3. REQUIREMENTS 3.1 Material. 3.1.1 Type A. The packing shall be made of virgin polytetrafluoroethylene (PTFE) yarn impregnated with a virg
17、in PTFE dispersion and lubricated with a heat resistant, inert lubricant. 3.1.2 Type B. The packing shall be made of virgin PTFE yarn impregnated with a virgin PTFE dispersion and shall contain no lubricant. with a virgin PTFE dispersion and shall contain no lubricant of any type and shall. be heat
18、cleansed for use against oxygen. 3.1.3 Tme C. The packing shall be made of virgin PTFE yarn impregnated 3.1.4 Yarn. The yarn shall be zero twist, in the range of 8400 to 11300 denier (see 4.5.6), multifilament virgin PTFE, preshrunk, and impregnated with a virgin PTFE dispersion before braiding (see
19、 4.5.4). The specific gravity of the yarn and dispersion shall be 2.15 k .O5 grams per cubic centimeter and have a melting point of 327 2 10 degrees Celsius. 3.1.5 Lubricant twe A only). The lubricant shall be a heat resistant inert petroleum oil weighing 15 5 percent of the finished type A packing
20、(see 4.5.3). 3.2 Construction. Types A, B, and C packing shall be braided, for sizes 1/4-inch and over, to a diagonal interlocking through-body-to-surface construction (as opposed to braid-over-braid or square-braid construction). This construction shall use either 20 or 36 braided diagonal strands
21、with center-corner-stuffer strands placed as required to produce a dense square packing with good dimensional stability that is square or trapezoidally shaped when straight. Sizes 1/8-inch and 3/16-inch only shall be square-braided only (see 4.5.2). 3.3 Sizes and weiphts. Types A, B, and C packing s
22、hall be formed approxi- mately square (or trapezoidal) in cross section “when straight“ and furnished in sizes shown in table I (see 6.2). The weight per linear foot shall be not less than that shown in table I. a 3 Provided by IHSNot for ResaleNo reproduction or networking permitted without license
23、 from IHS-,-,-MIL-P-2439bA 9999906 1973462 5TB = Nominal size (inches) MIL-P-24396A(SH) TABLE I. Sizes and weiEhts of packing. Minimum weight (pounds/f oo t ) Minimum weight t pounds/foo t ) Nominal size (inch) 1/8 1/4 3/8 1/2 5/8 3/4 3/16 5/16 7/16 9/16 11/16 13/16 O. 008 O. 026 O. 038 O. 062 o. 10
24、0 O. 135 O. 180 o. 220 O. 260 O. 320 O. 390 O. 460 7/8 15/16 1 1 - 1/8 1 - 1/4 1 - 3/8 1 - 5/8 1 - 3/4 1 - 7/8 2 -_ - O. 560 O. 640 O. 740 0.970 1.180 1.420 2.20G 2.300 2.550 2.850 - - 3.4 Spools or reels. Unless otherwise specified (see 6.2), the packing shall be uniformly coiled on spools or reels
25、 according to the following: Packinp - size (inches) Packape 1/8 through 7/16 1/8 through 3/4 3/8 through 3/4 3/4 through 1 1 - 1/8 through 2 1 pound (lb) spool 5 lb spool 10 lb spool 25, 50, or 100 lb reel 50 or 100 lb reel Limited quantities of packing 9/16-inch and over may be shipped as flat spi
26、ral coils. 3.5 Installation instructions. Installation, use, and precautionary instructions shall be furnished with each unit package. in the form of labels or printed inserts that will not be affected by water or grease. Where the instructions are placed within any opaque package, the outside of th
27、e package shall.be marked to indicate use instructions enclosed. The instructions may be 3.6 Workmanship. The packing shall be free from extraneous material and visible defects which may affect its serviceability (see 4.3.1). 4. QUALITY ASSURANCE PROVISIONS 4.1 Resvonsibilitv for inspection. Unless
28、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 order, the contractor may use his own or any other facilitie
29、s suitable for the performance of the inspection requirements specified herein, unless disapproved by the Government. The Govern- ment reserves the right to perform any of the inspections set forth in this specification where such inspections are deemed necessary to ensure supplies and services conf
30、orm to prescribed requirements. a 4 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-P-2439bA m 9999906 1973463 434 m Lot size 2 to 50 51 to 90 91 to 150 151 to 280 281 to 500 501 to 1,200 1.201 to 3,200 4.1.1 Responsibilitv for comliance. All ite
31、ms 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 responsibili
32、ty 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 requirements, however, this does not authorize sub
33、mission of known defective material, either indicated or actual, nor does it commit the Government to accept defective material. Sample size 5 7 11 13 16 19 23 4.2 Sampling. Random samples shall be selected from each lot as specified (see 6.3). 4.2.1 m. For purposes of sampling, a lot shall consist
34、of all finished The sampling packing of one size produced in a continuous run or at the same time under essentially the same conditions offered for delivery at one time. unit shall be one spool, reel, or coil of packing. 4.2.2 Sampling of visual and demensional examination and quality conformance te
35、sts. As a minimum, the contractor shall randomly select a sample quantity of completed packing material in accordance with table II and examine and test the packing material in accordance with 4.3.1 and 4.4. If one or more defects are found in any sample, the entire lot represented by the sample sha
36、ll be rejected. If a lot is rejected, the contractor has the option of screening 100% of the lot for the defective characteristic(s) or providing a new lot which shall be examined and tested in accordance with the sampling plan contained herein.(see 6.3) TABLE II. Sampling - for visual and dimension
37、al examination and aualitv conformance tests. 4.3.1 Examination for visual and dimensional defects. Each sample selected in accordance with table II shall be surface examined and measured to determine conformance with the requirements which do not require tests. containing one of more visual and dim
38、ensional defects shall be rejected, and shall be cause for rejection of the entire lot represented by the sample. Any sample O 5 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-P-2439bA 999990b 3973464 370 m 4.4 ualitv conformance tests. The samp
39、le selected in accordance with table II shall be tested as specified in 4.5.1 through 4.5.6. not conform to all the test requirements, this shall be cause for rejection of the lot which it represents. If a sample does 4.5 Test methods. 4.5.1 Weight. The weight shall be determined after carefully wei
40、ghing and measuring a specimen not less than 2 feet long. 4.5.2 Construction. The diagonal interlocking through-body-to-surface, braid-over-braid, and square-braid patterns are shown on figure 1 for visual examination. In addition, a 1- to 2-inch length of coil being examined shall be unbraided and
41、strands (not yarn plies or ends) counted and compared to the numbers as specified in 3.2. 4.5.3 Lubricant. The lubricant content of the finished type A packing shall be determined in accordance with ASTM D 2257, except for extracting 16 hours with the halogenated hydrocarbon solvent only, on duplica
42、te specimens taken from different parts of the packing. Results are calculated as P = 100E/S where, P = E = Weight of halogenated hydrocarbon solvent extract . S = Percent halogenated hydrocarbon solvent extract on the original samples. Specimen weight before extraction. 4.5.4 Tetrafluoroethvlene va
43、rn dispersion resin. The yarn and dispersion resin shall be tested after extraction in accordance with Melting Point Method of ASTM D 1457 to ensure that it is virgin PTFE resin. 4.5.5 SDecific gravity of PTFE resin, The specific gravity of the PTFE yarn and dispersion resin shall be determined in a
44、ccordance with ASTM D 792. 4.5.6 Denier. The denier of the PTFE yarn shall be determined in accordance with method 4021 of FED-STD-191. 4.6 Inspection of packaging. Sample packs and the inspection of packaging (preservation, packing, and marking) for shipment, stowage, and storage shall be in accord
45、ance with the requirements of section 5 and the documents specified therein. 5. PACKAGING (The packaging requirements specified herein apply only for direct Government acquisition.) 6 5.1 General. 5.1.1 Navv fire-retardant reauirements. Provided by IHSNot for ResaleNo reproduction or networking perm
46、itted without license from IHS-,-,-MIL-P-243bA m O6 1973465 207 m (a) Lumber and rlvwood. When specified (see 6.2), all lumber and plywood including laminated veneer materials used in shipping container and pallet construction, members, blocking, bracing, and reinforcing shall be fire-retardant trea
47、ted materials conforming to MIL-L-19140 as follows: Level A and B - Type II - weather resistant. Category 1 - general use. Level C - Type I - non-weather resistant Category 1 - general use. (b) Fiberboard. Fiberboard used in the construction of interior (unit and intermediate) and exterior fiberboar
48、d boxes including interior packaging forms shall conform to the class-domestic/fire retardant or class-weather resistant/fire-retardant materials equipment as specified (see 6.2), of ASTM D 4727 . 5.2 Preservation . Preservation shall be level A, C, or commercial, as specified (see 6.2). 5.2.1 Level
49、 A. 5.2.1.1 Preservation. Each package (see 3.4) shall be protected with a greaseproof barrier material conforming to MIL-B-121 or pliers option for type A packing, and a neutral barrier paper conforming to MIL-P-17667 for type B packing. Spiral coils, in flat form, shall be secured with a minimum of three ties placed equidistant apart. The greaseproof barrier material specified herein is not required when the unit container selected (see 5.2.1.
