1、MILITARY SPECIFICATION PACKING, ASBESTOS This specification is mandatory for use by all departments and agencies of the Department of Defense. * 1.1 Scope. material for use in hydraulic and mechanical components. This specification covers five types of asbestos packing I l 1.2 Classification. Packin
2、g shall be of the following types, grades, and classes, as specified (see 6.2). I- Type I Type II Type III Type IV Type V *Grade AA *Grade Under- writers Class E Class 2 Class 3 Class 4 Class 5 Soft-twisted, single strand Spiral-twisted single ply yam, 12 to 15 strands Twisted yarn, several strands
3、Braided, lubricated, and graphite coated Molded Yam asbestos Content 90% wt. up to but exclud- Yarn asbestos Content 80% wt. up to but exclud- Free of lubricant, rubber, and graphite Rubber frictioned, without lubricant, and coated with graphite on the outside only Single ply yarn, 18 to 22 strands,
4、 lubricated, and each strand coated with graphite Double ply yarn, 5 strands, lubricated, and outside surface coated with graphite Molded from braided asbestos tubing, lead- reinforced, lubricated, and outside surface coated with ZraDhite ing 95% wt. ing 85% wt. FSC 5330 Provided by IHSNot for Resal
5、eNo reproduction or networking permitted without license from IHS-,-,-MIL-P-16404B 2. APPLICABLE DOCUMENTS 2.1 The following documents, of the issue in effect on date of invita- tion for bids or request for proposal, form a part of this specification to the extent specified herein. SPECIFICATIONS Fe
6、deral *QQ-L-201 *S S-G- 6 5 9 *PPP-B-566 *PPP-B-636 *PPP-B-676 Military Lead Sheet Graphite, Dry (Lubricating) Box, Folding, Paperboard Box, Fiberboard Box, Setup *MIL-B-121 Barrier Material, Greaseproofed, Waterproofed, Flexible *MIL-L-10547 Liners, Case, and Sheet, Overwrap, Water- Vaporproof or W
7、aterproof, Flexible *MIL-L-25681 Lubricating Oil, Molybdenum Disulfide, Silicone Base, High Temperature STANDARDS Military *MIL-STD-105 Sampling Procedures and Tables for Inspection by Attributes *MIL-STD-O Quality Assurance Terms and Definitions MIL- STD-129 Marking for Shipment and Storage MIL-STD
8、-417 Rubber Composition, Vulcanized General Purpose, Solid (Copies of specifications, standards, drawings, and publications required by suppliers in connection with specific procurement functions Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-should
9、 be obtained from the procuring activity or as directed by the contracting officer.) *2.2 Other publications. The following documents form a part of this document to the extent specified herein. Unless otherwise indicated, the issue in effect on date of invitation for bids or request for pro- posal
10、shall apply. *American Society for Testing and Materials ASTM D 297 Standard Method of Chemical Analysis of Rubber Products ASTM D 299 Standard Specification for Asbestos Yarns ASTM D 1918 Method of Test for Asbestos Content of Asbestos Textile Materials (Application for copies of ASTM standards sho
11、uld be addressed to the American Society for Testing and Materials, 1916 Race Street, Philadelphia, Pa. 19103. ) (Technical society and technical association specifications and stan- dards are generally available for reference from libraries. also distributed among technical groups and using Federal
12、 agencies.) They are *Consolidated Classification Committee Uniform Freight Classification Rules National Motor Freight Classification (Application for copies should be addressed to the Consolidated Classi- fication Committee, 202 Chicago Union Station, Chicago, Ill. 60606.) 3. REQUIREMENTS *3.1 End
13、-item. Packing furnished under this specification shall be a product which has been inspected and passed the quality conformance inspection specified in section 4. *3.2 Materials. Materials shall be as specified herein and shall con- form to the applicable requirements of this specification. All mat
14、erials which are not specifically described herein shall be of the best quality 3 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-P-16404B and suitable for the purpose intended. Packing covered by this specifi- cation shall be made of asbestos ya
15、rn, with or without lubricant, rubber frictioning, graphite, and lead reinforcement, as specified for the various types and classes. *3.2.1 Asbestos. The asbestos used shall be the mineral chrysotile, containing not less than 12 percent by weight of water of hydration, in the form of textile materia
16、ls composed of organic fibers and asbes- tos (see 1.2). *3.2.2 Lubricants. The lubricant used in this packing shall be a noncorrosive oil conforming to MIL-L-25681. Lubricant for Classes 3 and 4 shall not exceed 20 percent by weight of the finished packing. Por Class 5 packing, the lubricant shall n
17、ot exceed 23 percent by weight of the finished packing. *3.2.3 Prictioning compound. The compound used in class 2 packing shall be made of type S class SB; grade 515 synthetic oil-resistant rubber in accordance with MIL-STD-417. The rubber content of type II, class 2 packing shall be not more than 1
18、0.0 percent by weight of the finished packing. *3.2.4 Graphite. Graphite coatings for classes 2, 3, 4, and 5 pack- ings shall be smoothly applied, and shall be 0.5 to 2.0 percent by weight of the finished packing. Graphite used for coating either the separate strands or the outer surface of packings
19、 shall conform to the require- ments of SS-6659, type “small particle size.“ *3.2.5 Lead. The lead used in class 5 packings shall be in accordance with QQ-L-201, grade B. 3.2.6 Yarn. *3.2.6.1 Weight of yarn. Single ply yarn shall weigh 1.00 f. 0.10 pound per 1,000 yards. *3.2.6.2 Grades of yam. Grad
20、e AA yarn shall contain 90.0 to 94.99 per- cent by weight of asbestos fiber. 80.0 to 84.99 percent by weight of asbestos fiber. Grade Underwriters yarn shall contain Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,- MIL-P-LbLlOVB 53 D 7777706 OLOL673
21、2 MIL-P-16404B *3.2.7 Sizing, organic fibers, and binder. The amount of sizing, organic fibers, and binder shall not exceed 10.0 percent by weight of the finished packing for Grade AA yarn and 20.0 percent by weight of the finished packing for Grade Underwriters yarn. 3.3 Construction and design. Un
22、less otherwise specified, the various types and classes of packing shall be constructed as indicated in 1.2, and shall have the following properties, *3.3.1 Characteristics of types and classes. Type I, class 1 Single strand, soft-twisted, free of lubricants, rubber and graphite, 0.047 i: .O07 inch
23、in diame- ter Type II, class 2 Spiral twisted from parallel strands to a cord 0.125 k .O18 inch in diameter. This construc- tion shall permit the ready adjustment of the diameter by unwinding the spiral, removing or adding parallel strands, and remapping to a different diameter Type III, class 3 0.1
24、88 f .O28 inches in diameter Type III, class 4 0.094 f .O14 inches in diameter Type IV Braided to size specified, and graphite coated Type V, class 5 Molded from braided asbestos tubing, reinforced with a strip of sheet lead approximately 0.010 inch thick by two-thirds the width of the finished part
25、 *3.3.2 Asbestos breaking strength. Asbestos breaking strength shall be as specified in contract or order. *3.4 Reaction with metals. The packing shall not cause corrosion or pitting of brass, copper, monel, or steel (see 4.4.2.1). *3.5 Adherence to metals, The packing shall not adhere or stick to b
26、rass, copper, monel, or steel, either through operation of the metallic Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-P-16404B parts within the packing or upon removal of the packing from the assem- bly (see 4.4.2.1). *3,6 Performance. The fini
27、shed asbestos packing shall be flexible and shall not leave hard or gummy deposits or cause corrosion to glands or valve stems, show hardening, loss of lubricant, or other deteriora- tion. *3.7 Worhanship. The packing shall be uniform in quality and free The frotn any irregularities which would adve
28、rsely affect performance. packing shall be consistent with the highest commercial practice of the industry. 4. QUALIT ASSURANCE PROVISIONS *4.1 Responsibility for inspection. Unless otherwise specified in the contract or purchase order, the supplier is responsible for the per- formance of all inspec
29、tion requirements as specified herein, Except as otherwise specified in the contract or order, the supplier may use his own or any other facilities suitable for the performance of the inspec- tion requirements specified herein, unless disapproved by the Government. The Government reserves the right
30、to perform any of the inspections set forth in this specification where such inspections are deemed necessary to assure supplies and services conform to prescribed requirements. *4.2 Quality conformance inspection. Quality conformance inspection shall consist of the following inspections performed u
31、pon each 3 ounce sample (see 4.3.3). Inspect ion Visual and dimensional Asbestos content Sizing, organic fibers, and binder Lubricant content Graphite content Rubber content Corrosion and Adhesion Strength lSample of asbestos yam used 2Sample of finished packing Paragraph 4.3.5 4.4.1.1 4.4.1.2 4.4.1
32、.3 4.4.1.4 4.4.1.5 4.4.2.1 4.4.2.2 Samples required All 3 ounces1 3 ounces1 3 ounces2 3 ounces2 3 ounces2 3 ounces2 3 ouncesl Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-P-16404B 4.3 Sampling Jc4.3.1 Inspection lot. A lot shall consist of fin
33、ished asbestos packing of the same material, type, grade, and class produced under essentially like conditions and submitted for acceptance at one time. *4.3.2 Sample size. When specified, the contractor shall furnish samples for inspection to determine conformance with this specifica- tion. in the
34、manufacture of each lot of packing, and 5 feet of the finished packing, or six finished molded packings of each item on contract or order. ber.and contract number and shall be inspected as specified herein and in accordance with the contract or order (see 6.2). forwarded as directed by the contracti
35、ng officer or agency. Samples shall consist of 3 ounces of the asbestos yarn used The samples shall be identified with the manufacturers part num- The samples shall be *4.3.3 Sampling for quality conformance inspection. A random sample of asbestos packing shall be taken from each lot in accordance w
36、ith MIL-STD-105, inspection level S-l. The acceptable quality level (AQL) shall be as specified in table I. definitions shall be in accordance with MIL-STD-109. The quality assurance terms and *Table I CLASSIFICATION OF DEFECTS FOR VISUAL AND DIMENSIONAL EXAMINATION OF THE END ITEM Categories Defect
37、s I Method of inspection Critical None defined AQL 1.0 percent Major 101 Size or tolerande incorrect Visual and SIE1 102 Packing stiff (lubricant missing) Visual 103 Graphite missing Visual 104 Configuration incorrect Visual Visual s IE 105 106 Weight of yarn incorrect Lead reinforcement missing . A
38、QL 4.0 percent Minor 201 Loose strands Visual Standard inspection equipment. 7 - - ,- Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-P-16 4 04B *4.3.4 Examination of preparation for delivery. An examination shall be made to determine that packag
39、ing and packing requirements comply with section 5 of this specification. level S-2 and the AQL shall be 2.5 percent defects per hundred units in accordance with MIL-STD-105. The inspection shall be inspection *4.3.5 Examination for visual and dimensional defects. Each packing taken at random, as sp
40、ecified in 4.3.3, shall be examined to verify conformance to requirements of this specification. conducted in accordance with table I. defects shall be rejected. Examination shall be Packings having one or more major 4.4 Test methods. 4.4.1 Physical properties tests. *4.4.1.1 Asbestos content. Tests
41、 shall be in accordance with ASTM D1918. Binder shall be removed prior to testing to determine asbestos content. the treatment can be completely removed prior to analysis. Treated asbestos textile materials may be tested providing *4.4.1.2 Sizing, organic fibers, and binder content. The percentage o
42、f sizing, organic fibers, and binder in the yarn shall be determined by subtracting the percent asbestos content from 100 percent. 4.4.1.3 Lubricant content. Weigh a 2-gram sample of the finished Extract with acetone for about packing into an extraction thimble. 4 hours in an Underwriters apparatus,
43、 taking care to lose as little graphite as possible in handling the sample. 212O Parenheit (I?) and reweigh. The loss of weight, in percent, is taken as the oil or lubricant content. Dry the sample at 4.4.1.4 Graphite content. Remove manually as much of the graphite as possible from the extracted sa
44、mple of 4.4.1.3. graphite. Weigh directly as A4.4.1.5 Rubber content. Tests for rubber and rubber content speci- fied in 3.2.3 shall be made in accordance with ASTM D 297. *4.4.2 Corrosion, adhesion, and strength tests. Provided by IHSNot for ResaleNo reproduction or networking permitted without lic
45、ense from IHS-,-,-MIL-P-16404B *4.4.2.1 Corrosion and adhesion tests. The packing shall be tested for corrosion and adhesion to brass, copper, monel metal, and steel to deter- mine compliance with the requirements of 3.4 and 3.5. A compression device shall be used for conducting these tests. This co
46、mpression device shall consist of a base plate provided with two studbolts on which polished plates of brass, copper, monel metal, and mild steel are suc- cessively placed. by 1/8 inch. imposing a load of 25 pounds per square inch, are placed over the studs and secured by a nut on top of each stud.
47、the spring loads so as to obtain the specified load on the packing speci- men. inch. Before running the test, the test strips of brass, copper, monel metal, and steel shall be cleaned with reagent grade benzene. of the above metals and a packing specimen are placed in the device and the stud nuts ar
48、e adjusted so that the springs impose a load of 25 pounds per square inch on the packing. The device assembly shall then be placed in an oven at 158“ F k 2“ for a period of 168 hours (1 week). At the end of this period the test assembly shall be removed from the oven and dis- assembled. The packing
49、contact surface of the metal test plate shall be carefully examined for corrosion and pitting. A slight discoloration of the metal shall not be considered as corrosion. The packing specimens shall be considered as adhering if particles or pieces of the packing remain in contact with the metal surface. This test shall be conducted for each kind of metal noted above. These plates used in this device shall measure
