1、- MIL-S-5250bD 43 99999Ob 11b23bD 716 = 1 INCH-POUND 1 MI L-S-52506D (ME) 30 July 1992 . SUPERSEDING MIL-S-52506C(ME) 27 December 1984 MILITARY SPECIFICATION SEALS, SHAFT, MECHANICAL, LOW-PRESSURE TYPE, SELF-LUBRICATING: FOR GENERAL-PURPOSE CENTRIFUGAL PUMPS This specification is approved for use wi
2、thin the USA Belvoir Research, Development and Engineering Center, Department of the Army, and is available for use by all Departments and Agencies of the Department of Defense. 1. SCOPE 1.1 ScoDe. This specification covers four types and 16 sizes of low-pressure, self-lubricating, mechanical shaft
3、seals, commonly used on centrifugal pumps. 1.2 Classification. The seals shall be of the following types and sizes, as specified (see 6.2): Type 1 - Pressed-in type with stationary sealing washer and rotating seating surface (see figure 1). Size 3 - for 0,375-inch diameter shafts. Size 4 - for 0.500
4、-inch diameter shafts. Size 5 - for 0.625-inch diameter shafts. Size 6 - for 0.750-inch diameter shafts. Type II - Short-length type with rotating sealing washer and stationary seating surface (see figure 2). Size 3 - for 0.375- Size 4 - for 0.500- Size 5 - for 0.625- Size 6 - for 0.750- Size 7 - fo
5、r 0.875- Size 8 - for 1.000- Size 8-1/2 - for 1.062- Size 9 - for 1.125- Size 10 - for 1.250- nch diameter shafts. nch diameter shafts. nch diameter shafts. nch diameter shafts. nch diameter shafts. nch diameter shafts. nch diameter shafts. nch diameter shafts. nch diameter shafts. Beneficial commen
6、ts (recommendations, additions, deletions) and any pertinent data which may be of use in improving this document should be addressed to: USA Belvoir Research, Development, and Engineering Center, ATTN: SATBE-TSE, 22060-5606 by using the Standardization Document Improvement 1426) appearing at the end
7、 of this document or by letter. AMSC N/A FSC 4320 DISTRIBUTION STATEMENT A. Approved for public release; distribution is unlimited. Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-Type III Size 3 Size 4 Size 5 Size 6 Size 7 Size 8 Size 9 Size 10 Type
8、 IV MIL-S-5250bD Li3 999990b LLb23bL b52 - - Small-diameter type with rotating sealing washer and stationary seating surface (see figure 3). - for 0.375-inch diameter shafts. - for 0.500-inch diameter shafts. - for 0.625-inch diameter shafts. - for 0.750-inch diameter shafts. - for 0.875-inch diamet
9、er shafts. - for 1.000-inch diameter shafts. - for 1.125-inch diameter shafts. - for 1.250-inch diameter shafts. - Flexible-for-misalignment type with rotating sealing washer and stationary seating surface (see figure 4). Size 8 - for 1.000-inch diameter shafts. Size 8-1/2 - for 1.062-inch diameter
10、shafts. Size 9 - for 1.125-inch diameter shafts. Size 10 - for 1.250-inch diameter shafts. Size 12 - for 1.500-inch diameter shafts. Size 14 - for 1.750-inch diameter shafts. Size 16 - for 2.000-inch diameter shafts. Size 18 - for 2.250-inch diameter shafts. Size 20 - for 2.500-inch diameter shafts.
11、 Size 22 - for 2.750-inch diameter shafts. Size 24 - for 3.000-inch diameter shafts. 2. APPLICABLE DOCUMENTS 2.1 Government documents. 2.1.1 Specifications and standards. The following specif form a part of this document to the extent specified herein. specified, the issues of these documents are th
12、ose listed in Department of Defense Index of Specifications and Standards supplement thereto, cited in the solicitation (see 6.2). SPECIFICATIONS FEDERAL PPP-B-566 - Boxes, Fol ding, Paperboard. PPP-B-601 - Boxes, Wood Cleated-Plywood. PPP-B-636 - Boxes, Shipping, Fiberboard. M I L ITARY cations and
13、 standards the issue of the DoDISS) and Un1 ess otherwi se MIL-1-10 - Insulating Materials, Electrical, Ceramic, Class L. MIL-P-116 - Preservation, Methods of. 2 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-S-52506D (ME) STANDARDS MI L I TARY
14、MIL-STD-105 MIL-STD-129 MIL-STD-130 - Identification Marking of US Military Property. MIL-STD-889 - Di ssimi 1 ar Metal s. - Sampl i ng Procedures and Tab1 es for Inspect i on by - Marking for Shipment and Storage. Attributes. (Unless otherwise indicated, copies of federal and military specification
15、s, and standards are available from the Standardization Documents Order Desk, Building 4D, 700 Robbins Avenue, Philadelphia, PA 19111-5094.) 2.2 Non-Government Dublications. The following document(s) form a part of this document to the extent specified herein. of the documents which are DoD adopted
16、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). Unless otherwise specified, the issues AMERICAN SOCIETY FOR TESTING AND MATERIALS (
17、ASTM) A 167 - Stainless and Heat-Resisting Chromium-Nickel Steel Plate, Sheet, and A 313 - Chromium-Nickel Stainless and Heat-Resisting Steel Spring Wire. A 319 - Gray Iron Castings for Elevated Temperatures for Non-Pressure C 135 - True Specific Gravity of Refractory Materials by Water Immersion. C
18、 886 - Scleroscope Hardness Testing of Fine-Grain Carbon and Graphite D 2000 - Elastomeric Materials for Automotive Applications. D 3953 - Strapping, Flat Steel and Seals. D 4675 E8 E9 E 228 Strip. Containing Parts. Materials. - Selection and Use of Flat Strapping Materials. - Tension Testing of Met
19、allic Materials. - Compression Testing of Metallic Materials at Room Temperature. - Linear Thermal Expansion of Solid Materials with a Vitreous Silica Di 1 atometer. (Applications for copies should be addressed to the American Society for Testing and Materials, 1916 Race Street, Philadelphia, PA 191
20、03.) NATIONAL MOTOR FREIGHT TRAFFIC ASSOCIATION, INC. (NMFTA) National Motor Freight Classification Rules (Application for copies should be addressed to the American Trucking Association, Inc., ATTN: Traffic Order Section, 2200 Mill Road, Alexandria, VA 22314.) 3 Provided by IHSNot for ResaleNo repr
21、oduction or networking permitted without license from IHS-,-,-MIL-S-5250bD 43 m Ob 3362363 425 UNIFORM CLASSIFICATION COMMITTEE (UCC) Uniform Freight Classification Rules (Application for copies should be addressed to Uniform Classification Committee, ATTN: Tariff Publishing Officer, Room 1106, 222
22、S. Riverside Plaza, Chicago, IL 60606. ) (Non-Government standards and other publications are normally available from the organizations that prepare or distribute the documents. be available in or through libraries or other informational services.) These documents also may 2.3 Order of wecedence. In
23、 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. REQU I REMENTS 3.1 OescriDtion. Each
24、 seal shall consist essentially of a seat, seat ring, carbon seal washer, bellows, retainer, spring, drive band, and spring holder. 3.2 First article. Unless otherwise specified (see 6.2), a sample shall be subjected to first article inspection (see 6.3) in accordance with 4.3. 3.3 Materials. Materi
25、als shall be as specified herein. Materials not specified shall be selected by the contractor and shall be subject to a 1 provisions of this specification. 3.3.1 Cadmium Dlatinq. Cadmium plating and cadmium plated items sha used. 1 not be 3.3.2 Material deterioration prevention and control. The seal
26、 shall be fabricated from compatible materials, inherently corrosion resistant or treated to provide protection against the various forms of corrosion and deterioration that may be encountered in any of the applicable operation and storage environments to which the seal may be exposed. 3.3.2.1 Dissi
27、milar metals. Dissimilar metals shall not be used in intimate contact with each other unless protected against galvanic corrosion. metals and methods of protection are defined and detailed in MIL-STD-889. Dissimilar 3.3.2.2 Identification of materials and finishes. The contractor shall identify the
28、specific material, material finish or treatment for use with component and subcomponent, and shall make information available upon request to the contracting officer or designated representative. 3.3.2.3 Recovered materials. For the purpose of this requirement, recovered materials are those material
29、s which have been collected from solid waste and reprocessed to become a source of raw materials, as distinguished from virgin raw materials. The components, pieces and parts incorporated in the seals may be newly fabricated from recovered materials to the maximum extent practicable, provided the se
30、als produced meets all other requirements of this specification. 4 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,- MIL-S-52506D 43 m 9999906 1162364 361 m MIL-S-52506D(ME) Used, rebuilt or remanufactured components, pieces and parts shall not be inc
31、orporated in the seal s. 3.4 Sealins wacher. The sealing washer shall be a mixture of carbon, graphite, The sealing washer shall have the following physical and either babbitt or resin. properties: Hardness, minimum Compressive strength, minimum Transverse strength, minimum Tensile strength, minimum
32、 Specific gravity Coefficient of linear thermal expansion, maximum Resistance to heat as Resin type Babbitt type specified (see 6.2): 60 (using ASTM C 886) 32,000 pounds per square inch (psi) 10,000 psi 2900 psi 1.75 minimum - 3.20 maximum 2.95 X (1/“F) 500 OF (260 OC) 300 “F (149 OC) 3.5 Seat. The
33、seat shall be gray iron alloy conforming to ASTM A 319, class I or II; or ceramic material conforming to MIL-1-10, grade L524 C, as specified (see 6.2). 3.6 Static seals. The seat ring or the O-ring and the bellows shall be an elastomer meeting the requirements of ASTM D 2000, line call out M2BG614A
34、14B14EF21034F17. All rubber seals shall be less than 12 months old on date of acceptance by the Government. 3.7 Retainer. The retainer shall be corrosion-resistant steel conforming to ASTM A 167, UNS S30400. 3.8 Swinq. The spring shall be corrosion-resistant steel conforming to ASTM A 313, UNS S3020
35、0 or S30400. 3.9 Drive band and sDrinci holder. The drive band and spring holder shall be corrosion-resistant steel conforming to ASTM A 167, UNS S30400. 3.10 Seal contact surfaces. The seal contact surfaces shall be lapped flat and smooth to not more than 4 light bands for the softer surface and no
36、t more than 3 light bands for the harder surface. 3.11 Performance. The seal shall prevent leakage of liquid between the rotating pump shaft and the adjacent stationary pump parts at the shaft speed and pressure specified on the applicable figures. escaped liquid from the seal after run-in. There sh
37、all be no accumulation of 3.12 Lubrication. The seal shall be lubricated with light oil during initial installation of the seal. Subsequently, the seal shall be continuously self- lubricating utilizing the fluid being pumped. 3.13 Identification markinq. The seal shall be identified in accordance wi
38、th MIL-STD-130 and shall include part or identifying numbers (see 6.4). Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-3.14 WorkmanshiP. All parts, components, and assemblies of the seal including casting, molded parts, stampings, machined surfaces,
39、 and welded parts shall be clean and free from sand, dirt, fins, pits, sprues, scale, flux, and other harmful extraneous material. All edges shall be rounded or beveled. 4. QUALITY ASSURANCE PROVISIONS 4.1 Responsibility for inspection. Unless otherwise specified in the contract or purchase order, t
40、he 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 performance of the inspection require
41、ments 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 requirements. 4.1.1 ResDonsibility for co
42、mpliance. 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
43、 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 an acceptable practice to ascertain conformance to requirements, however, this does not
44、authorize submission of known defective material, either indicated or actual, nor does it commit the Government to acceptance of defective material. 4.1.2 Component and material inspection. The contractor is responsible for insuring that components and materials are manufactured, examined, and teste
45、d in accordance with referenced specifications and standards, as applicable. 4.2 Classification of inspections. The inspection requirements specified herein are classified as follows: a. First article inspection (see 4.3). b. Quality conformance inspection (see 4.4). c. Inspection of packaging (see
46、4.6). 4.3 First article inspection. 4.3.1 Examination. The first article seal shall be examined as specified in 4.5.1. Presence of one or more defects shall be cause for rejection. 4.3.2 Tests. The first article seal shall be tested as specified in 4.5.2.1 through 4.5.2.5. Failure of any test shall
47、be cause for rejection. 4.4 Quality conformance inspection. 4.4.1 Sampling. Sampling for examination and tests shall be in accordance with MIL-STD-105. Sample size shall be determined by using MIL-STD-105 table I and table IIa. A lot shall be accepted when zero defects are found and rejected when on
48、e or more defects are found. 6 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-S-5250bD 43 9999906 11623bb 134 D 4.4.2 Examination. Samples selected in accordance with 4.4.1 shall be examined as specified in 4.5.1. Presence of one or more defects
49、 shall be cause for rejection. 4.4.3 Tests. Samples selected in accordance with 4.4.1 shall be tested as specified in 4.5.2.2, 4.5.2.3, and 4.5.2.4, except that the run-in time shall be the contractor?s option. Presence of one or more defects shall be cause for rejection. 4.5 InsPection procedure. 4.5.1 Examination. The seal shall be examined as specified herein for the fol 1 owing major defects : Major 101. 102. 103. 104. 105. 106. 107. 108. 109. 110. 111. 112.
