1、Comments, suggestions, or questions on this document should be addressed to Commander, Naval Sea Systems Command, ATTN: SEA 05S, 1333 Isaac Hull Avenue, SE, Stop 5160, Washington Navy Yard DC 20376-5160 or emailed to CommandStandardsnavy.mil, with the subject line “Document Comment”. Since contact i
2、nformation can change, you may want to verify the currency of this address information using the ASSIST Online database at https:/assist.daps.dla.mil. AMSC N/A FSC 5330 INCH-POUND MIL-PRF-32287A 15 February 2011 SUPERSEDING MIL-PRF-0032287(SH) 03 June 2009 PERFORMANCE SPECIFICATION PACKING, PREFORME
3、D, PETROLEUM HYDRAULIC FLUID RESISTANT This specification is approved for use by all Departments and Agencies of the Department of Defense. 1. SCOPE 1.1 Scope. This specification covers O-ring packings for shipboard use with petroleum-based hydraulic fluids conforming to MIL-PRF-87257 and MIL-PRF-83
4、282 over the temperature range of -65 to 275 F (-54 to 135 C). 1.2 Classification. 1.2.1 Sizes. The O-rings conform to sizes shown in SAE-AS-28775. 2. APPLICABLE DOCUMENTS 2.1 General. The documents listed in this section are specified in sections 3, 4, or 5 of this specification. This section does
5、not include documents cited in other sections of this specification or recommended for additional information or as examples. While every effort has been made to ensure the completeness of this list, document users are cautioned that they must meet all specified requirements of documents cited in se
6、ctions 3, 4, or 5 of this specification, whether or not they are listed. 2.2 Government documents. 2.2.1 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
7、 of these documents are those cited in the solicitation or contract. DEPARTMENT OF DEFENSE SPECIFICATIONS MIL-PRF-6083 - Hydraulic Fluid, Petroleum Base, for Preservation and Operation MIL-PRF-83282 - Hydraulic Fluid, Fire Resistant, Synthetic Hydrocarbon Base, Metric, NATO Code Number H-537 MIL-PRF
8、-87257 - Hydraulic Fluid, Fire Resistant; Low Temperature Synthetic Hydrocarbon Base, Aircraft and Missile DEPARTMENT OF DEFENSE STANDARDS MIL-STD-413 - Visual Inspection Guide for Elastomeric O-Rings MIL-STD-1916 - DoD Preferred Methods for Acceptance of Product (Copies of these documents are avail
9、able online at https:/assist.daps.dla.mil/quicksearch/ or from the Standardization Document Order Desk, 700 Robbins Avenue, Building 4D, Philadelphia, PA 19111-5094.) Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-PRF-32287A 2.3 Non-Government p
10、ublications. The following documents form a part of this document to the extent specified herein. Unless otherwise specified, the issues of these documents are those cited in the solicitation or contract. ASME INTERNATIONAL ASME B46.1 - Surface Texture (Surface Roughness, Waviness, and Lay) (Copies
11、of this document are available from ASME International, 22 Law Drive, P.O. Box 2900, Fairfield, NJ 07007-2900 or online at www.asme.org.) ASTM INTERNATIONAL ASTM D1414 - Standard Test Methods for Rubber O-Rings (Copies of this document are available from ASTM International, 100 Barr Harbor Dr., P.O.
12、 Box C700, West Conshohocken, PA 19428-2959 or online at www.astm.org.) SAE INTERNATIONAL SAE-AMS-5513 - Steel, Corrosion-Resistant, Sheet, Strip, and Plate 19Cr 9.2Ni (SAE 30304) Solution Heat Treated SAE-AMS-5630 - Steel, Corrosion-Resistant, Bars, Wire, and Forgings, 17Cr 0.52Mo (0.95 1.20C) (SAE
13、 51440C) SAE-AMS-6350 - Steel Sheet, Strip, and Plate, 0.95Cr 0.20Mo (0.28 - 0.33C) (SAE 4130) SAE-AMS-QQ-A-250 - Aluminum and Aluminum Alloy, Plate and Sheet; General Specification for SAE-AS-5440 - Hydraulic Systems, Military Aircraft, Design and Installation Requirements for SAE-AS-28775 - Packin
14、g, Preformed, MS28775 O-Ring (Copies of these documents are available from SAE World Headquarters, 400 Commonwealth Drive, Warrendale, PA 15096-0001 or online at www.sae.org.) 2.4 Order of precedence. Unless otherwise noted herein or in the contract, in the event of a conflict between the text of th
15、is 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 3.1 Qualification. The packings furnished under this specification shal
16、l be products that are authorized by the qualifying activity for listing on the applicable qualified products list before contract award (see 4.3 and 6.3). 3.2 Materials. The packings shall be manufactured from a synthetic rubber which is compatible with hydraulic fluid conforming to MIL-PRF-87257.
17、The polymeric ingredient of the synthetic rubber shall be a copolymer of butadiene/acrylonitrile. The finished product shall contain no substance which will adversely affect the properties of the fluid or the packings. 3.2.1 Recycled, recovered, or environmentally preferable materials. Recycled, rec
18、overed, or environmentally preferable materials should be used to the maximum extent possible, provided that the material meets or exceeds the operational and maintenance requirements, and promotes economically advantageous life cycle costs. 3.3 Dimensions and tolerances. The dimensions and toleranc
19、es of O-rings procured to this specification shall conform to SAE-AS-28775. 3.4 Physical properties. The physical properties of the rubber shall conform to values given in table I. 2 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-PRF-32287A 3.4.
20、1 Variations. The permissible variations in physical properties during actual production from those values obtained in the qualification tests shall be as follows: a. Specific gravity 0.02 b. Tensile strength, percent 20 c. Elongation, percent 20 (ultimate elongation shall not be less than 160 perce
21、nt) In addition, all physical properties tested shall meet the requirements specified in table I. TABLE I. Physical properties. Properties RequirementsOriginal properties Specific gravity As determined Hardness, Type A, points 68, minimum Tensile strength, psi 1350, minimum Elongation, % 160, minimu
22、m (may not be lower than 160% in production) Tensile stress (modulus) psi at 100% elongation 500, minimum Temperature Retraction, TR-10 50% elongation and 10% return, F -49, maximum Corrosion adhesion Slight corrosion allowed on 4130 steel, none on other metals Properties after aging 70 hours at 275
23、5 F in MIL-PRF-87257 Hardness change, Type A, points +5, -15 Tensile strength decrease, % 50, maximum Elongation decrease, % 35, maximum Volume change, % 1 to 20 Compression set, 25% deflection % of original deflection 55, maximum Temperature retraction, TR-10 50% elongation and 10% return, F -49, m
24、aximum Properties after aging 70 hours at 2755 F in MIL-PRF-83282 Hardness change, Type A, points 10 Tensile strength decrease, % 40, maximum Elongation decrease, % 45, maximum Volume change, % 0.5 to 15 Compression set, 25% deflection, % of original deflection 55, maximum Temperature retraction, TR
25、-10 50% elongation and 10% return, F -47, maximum 3.5 Dynamic cycling. When tested in accordance with 4.6, the O-rings shall withstand a minimum of 75,000 cycles without failure. Failure is determined as that number of cycles at which a test ring leaks a total of 70 ml of hydraulic fluid. Each test
26、consists of at least one test cell containing two rings. A minimum of six test runs shall be conducted making a total of six test cells to be tested. The number of cycles until failure shall be recorded. The highest number of cycles and the lowest number of cycles shall be discarded. The remaining 4
27、 values shall be averaged and that value must be 75,000 minimum for the O-rings to pass the test. 3 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-PRF-32287A 4. VERIFICATION 4.1 Classification of inspections. The inspection requirements specifie
28、d herein are classified as follows: a. Qualification inspection (see 4.3). b. Conformance inspection (see 4.4). 4.2 Test conditions. 4.2.1 Fluid. The fluid aging in this specification shall be conducted using hydraulic fluids qualified to MIL-PRF-87257 and MIL-PRF-83282, as applicable. New fluid sha
29、ll be used for each aging test. 4.2.2 Atmospheric conditions. All fluid cooling, conditioning, and physical property determinations shall be conducted in an atmosphere of 5015 percent relative humidity and at a temperature of 755 F. 4.3 Qualification inspection. Qualification inspection shall be per
30、formed on packings when a qualification sample is required (see 3.1). This inspection shall include the tests of 4.5 through 4.6. 4.3.1 Samples. Test samples shall be O-rings conforming to SAE-AS-28775 Size-214. SAE-AS-28775 Size-218 O-rings are also required for dynamic cycling test (see 4.6). Hard
31、ness shall be determined on hardness discs not less than 14 inch thickness. 4.4 Conformance inspection. Conformance inspection shall include the examination of 4.4.3 and the conformance tests in 4.4.4. 4.4.1 Sampling for inspection. Sampling for conformance inspection shall be in accordance with MIL
32、-STD-1916, except where otherwise indicated herein. Conformance tests are required for all production batches of material. 4.4.1.1 Batch. A batch shall be the quantity of material compounded on a mill or mixer at one time. A batch shall include SAE-AS-28775 Size-214 O-rings and hardness discs for co
33、nformance tests. A batch shall consist of a maximum of 200 pounds. If more than 200 pounds of material is produced at one time, conformance tests shall be conducted on each 200 pounds of material. 4.4.2 Conformance test samples. The test samples shall be SAE-AS-28775 Size-214 O-rings conforming to S
34、AE-AS-28775. Hardness discs shall be used for hardness determinations. 4.4.3 Inspection of the end item. Examination of the end item shall be in accordance with the classification of defects, inspection levels, and acceptance criteria as specified, in the contract or purchase order (see 6.2). The lo
35、t size, for the purpose of determining the sample size in accordance with MIL-STD-1916, shall be expressed in units of O-rings. 4.4.3.1 Examination for defects in appearance and workmanship. The examination shall be in accordance with MIL-STD-413. The sample size shall be in accordance with an inspe
36、ction level of MIL-STD-1916 and acceptance criteria as specified (see 6.2). 4.4.3.2 Examination for dimensional defects. The examination shall be made to the tolerances specified in SAE-AS-28775. Each size shall be inspected for dimensional and tolerance conformance. Each size shall be independent o
37、f other sizes for sampling quantities. The sample size shall be in accordance with an inspection level of MIL-STD-1916 and acceptance criteria as specified (see 6.2). 4.4.4 Conformance tests. The following tests shall be conducted on each batch of material (see 4.4.2) and table I: Original Propertie
38、s Tests only Specific gravity Hardness Tensile strength Elongation 4 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-PRF-32287A Size-214 in accordance with SAE-AS-28775 shall be used as test samples. Hardness discs shall be used for the hardness
39、test. 4.4.4.1 Rejection criteria. A lot shall be rejected upon the failure of any sample to meet the test requirements specified herein. 4.5 Test methods. 4.5.1 Physical properties. Unless otherwise specified herein, physical properties shall be determined in accordance with ASTM D1414 (see 3.4). 4.
40、5.2 Fluid aging. The containers used for fluid aging shall be of the conventional fruit jar type. The cover for the container shall be either the two piece (lid and ring) fruit jar type, except that the lid shall be inverted in order that the lids flat surface comes in contact with the sealing surfa
41、ce of the container, or a glass cover held firmly in place by a wire-lever apparatus. Unclean, uneven sealing surfaces of the cover and container and oil contact with the sealing surfaces shall be avoided. During oil aging the O-rings shall be suspended in the oil by a glass or nichrome wire rack in
42、 such a manner that the O-rings will not come in contact with any part of the container. The hardness discs shall be placed loosely in the jars. Immediately after the aging period and before physical property determinations, the O-rings and hardness discs shall be cooled in new fluid for a period of
43、 not less than 30 minutes at 775 F. 4.5.3 Corrosion and adhesion. SAE-AS-28775 Size-214 O-rings, two for each metallic plate below and using whole uncut rings, shall be prepared for corrosion testing by inserting sufficient quantities of the seals in a desiccator or similar humidity chamber maintain
44、ed at 92 percent minimum relative humidity and 755 F for at least 72 hours. Plates of the metals listed below shall be polished to a surface roughness of 4 to 16 roughness height range (RHR) in accordance with ASME B46.1. The edges shall also be polished to reduce the formation of edge corrosion. Th
45、e plates shall be washed with toluene or aliphatic naphtha, or similar decreasing agent that will produce a clean dry surface free from film. The metals used shall be as follows: SAE-AMS-QQ-A-250 Aluminum Alloy 2024 SAE-AMS-QQ-A-250 Aluminum Alloy 6061 SAE-AMS-QQ-A-250 41uminum Alloy 7075 SAE-AMS-56
46、30 440C Stainless Steel SAE-AMS-5513 304 Stainless Steel SAE-AMS-6350 4130 Steel, Aircraft Quality The humidified seals and the metallic plates shall be immersed in MIL-PRF-6083, Type I fluid and drained to the drop point. The seals and plates shall then be so laid together in a stack that at least
47、two whole seals contact each specified metal. The stack shall be held together with a pressure of 20 to 30 pounds and placed in a desiccator which is maintained at not less than 92 percent relative humidity at 755 F. This relative humidity may be produced by the use of salt of sufficient concentrati
48、on in solution with distilled water. No more than 15 minutes should be required for assembling the test samples. Time of humidity exposure for this portion of test shall be 14 days. At the termination of this test, the procedures outlined below shall be followed: a. The surface of the plates which w
49、ere in contact with the seals shall be inspected for discoloration, deposits, pitting, or other evidence of corrosion or adhesion. If any exist, the surfaces of the plates shall be washed in aliphatic naphtha. Deposits determined as rubber compounds or elements therefrom, which can be removed by this process and which do not occur on other surfaces of the plates, shall be construed as adhesion. b. Any pits or eroded marks remaining after this pr
