1、AMSC N/A FSC 4730 DISTRIBUTION STATEMENT A. Approved for public release; distribution is unlimited. MIL-DTL-25531F 31 July 2013 SUPERSEDING MIL-DTL-25531E 05 June 1996 DETAIL SPECIFICATION COUPLING HALF, QUICK DISCONNECT, PNEUMATIC STARTER, EXTERNAL, LOW PRESSURE INCH-POUND INACTIVE FOR NEW DESIGN C
2、omments, suggestions, or questions on this document should be addressed to Oklahoma City Air Logistics Center/ENSDAA, 3001 Staff Drive, Suite 1AB81A, Tinker AFB, OK 73145 or emailed to tinker.dsptinker.af.mil. Since contact information can change, you may want to verify the currency of this address
3、information using the ASSIST Online database at https:/assist.dla.mil. Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-DTL-25531F 2 This specification is approved for use by all Departments and Agencies of the Department of Defense. 1. SCOPE 1.1
4、Scope. This specification covers the general requirements for quick-disconnect external low pressure half couplings for a pneumatic starter, with primary and secondary methods of release and, automatic pressure lock with self-closing valves. 2. APPLICABLE DOCUMENTS 2.1 General. The documents listed
5、in this section are specified in sections 3, 4, or 5 of this specification. This section does 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 these lists, docu
6、ment users are cautioned that they must meet all specified requirements of documents cited in sections 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 for
7、m 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. FEDERAL SPECIFICATIONS RR-C-271 - Chains and Attachments, Carbon and Alloy Steel DEPARTMENT OF DEFENSE SPECIFICATIONS MIL-S-7742 - Scre
8、w Threads, Standard, Optimum Selected Series: General Specification for MIL-A-8625 - Anodic Coatings for Aluminum and Aluminum Alloys MIL-DTL-22706 - Duct and Scuff Cover, Pneumatic, Flexible MIL-DTL-32258 - Nut, Self-Locking (Ring Type Non-Metallic Insert), Heavy Hex, Controlled Root Radius, Nickel
9、-Copper Alloy MS17833 - Connector, Pneumatic Starter Duct, Flanged, Male MS33740 - Nipple, Pneumatic Starting, 3 Inch ID DEPARTMENT OF DEFENSE STANDARDS MIL-STD-130 - Identification Marking of U.S. Military Property MIL-STD-889 - Dissimilar Metals MIL-STD-31000 - Technical Data Packages Provided by
10、IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-DTL-25531F 3 (Copies of these documents are available online at https:/assist.dla.mil/quicksearch/ or from the Standardization Document Order Desk, 700 Robbins Avenue, Building 4D, Philadelphia, PA 19111-5094.)
11、 2.3 Non-Government publications. 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. AEROSPACE INDUSTRIES ASSOCIATION of AMERICA, INC. (AIA) NASM20995 - Wire,
12、Safety or Lock NASM33540 - Safety Wiring and Cotter Pinning NASM90725 - Screw, Cap, Hexagon Head (Finished Hexagon Bolt), Steel, Grade 5, Cadmium Plated, UNC-2A (NA/NAS documents may be obtained online at www.aia-aerospace.org/ or from Aerospace Industries Association 1000 Wilson Boulevard, Suite 17
13、00 Arlington, VA 22209-3928.) SAE INTERNATIONAL SAE-AS9581 - Washer, Key-Cres, AMS 5510. 90 DEG. Locking (SAE documents may be obtained online at http:/www.sae.org/ or from SAE World Headquarters, 400 Commonwealth Drive, Warrendale, PA 15096-0001 USA.) 2.4 Order of Precedence. Unless otherwise noted
14、 herein or in the contract, in 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. REQUIR
15、EMENTS 3.1 Qualification. The coupling furnished under this specification shall be a product which has been tested and has passed the qualification tests specified herein, and has been listed on or approved for listing on the applicable Qualified Products List. 3.2 Commercial parts. Commercial parts
16、 having suitable properties may be used where, on the date of invitation for bids, there are no suitable standard parts. In any case, commercial utility parts, such as screws, bolts, nuts, and cotter pins, having suitable properties may be used provided: a. They can be replaced by the standard parts
17、 (MS or AN) without alteration. b. The corresponding standard part numbers are referenced in the parts list and, if practical, on the contractors drawings. Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-DTL-25531F 4 3.2.1 Standard parts. With th
18、e exception specified in 3.2.a, MS and AN standard parts shall be used where they suit the purpose. They shall be identified on the drawings by their part numbers. 3.3 Materials. 3.3.1 Fungus-proof materials. Materials that are nutrients for fungi shall not be used where it is practical to avoid the
19、m. Where used and not hermetically sealed, they shall be treated with a fungicide agent acceptable to the procuring activity. However, if they will be used in a hermetically sealed enclosure, fungicide treatment will not be necessary. 3.3.2 Metals. Metals shall be of the corrosion-resistant type or
20、suitably treated to resist corrosion due to fuels, salt spray, or atmospheric conditions which may be encountered in storage or normal service. 3.3.2.1 Dissimilar metals. Unless suitably protected against electrolytic corrosion, dissimilar metals shall not be used in intimate contact with each other
21、. Dissimilar metals are defined in MIL-STD-889. 3.3.3 Recycled, recovered, or environmentally preferable materials. Recycled, recovered, or environmentally preferable materials should be used to the maximum extent possible, provided that the material meets or exceeds the operational and maintenance
22、requirements, and promotes economically advantageous life cycle costs. 3.4 Design. The coupling shall conform dimensionally to Figure 1 and shall be in accordance with the following requirements. One end of the coupling shall mate with the MS33740 nipple and the other end shall mate with the flange
23、of hose and fitting MS17833. No part of the coupling shall protrude into the nipple bore. Three holes shall be provided as stated in paragraph 3.5.2 for possible attachment of handling ring. 3.4.1 Reliability. The coupling shall be designed and constructed as specified herein in a manner that will i
24、nsure the highest degree of operational reliability under all service conditions. 3.4.2 Instructions. Brief appropriate operating instructions such as “PUSH COLLAR FORWARD TO LOCK,“ or a directional arrow shall be provided as a permanent part of the coupling, preferably a part of the outer coupling
25、casting. 3.5 Construction. The coupling shall be so constructed that it will withstand the strains, jars, vibrations, and other conditions incident to installation and service usage. 3.5.1 Maintainability. The coupling shall have a minimum number of parts consistent with reliability. Its design shal
26、l permit easy assembly, disassembly, location of trouble sources, and maintenance with tools normally available commercially, by service maintenance personnel with a minimum of training. Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-DTL-25531F
27、5 (a) Protuberance shall not extend more than 2 inches along circumference at outside radius of body of coupling. Flange fitting end piece to mate with flange of MS17833. Dimensions in inches, unless otherwise specified, tolerances .010 inch. FIGURE 1. Coupling half, quick disconnect, pneumatic star
28、ter, external, low pressure. Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-DTL-25531F 6 3.5.2 Handling ring attachment holes. The coupling housing (collar) shall contain three holes. The holes shall be spaced 120 degrees apart, circumferentiall
29、y, with one of the holes located 180 degrees circumferentially from the point of the handling ring attachment. Each hole shall be located axially .460/.540 inches from end of the coupling housing and shall be tapped for .3125 - 24UNF - 2b threads of MIL-S-7742 to a minimum depth of 0.380 inch (See F
30、igure 1). 3.5.3 Handling ring. Ring is to be dimensional such that it will not interfere with aircraft structure or equipment attached to the aircraft. Configuration shall be approved by the specification preparing activity. Ring is currently available under National Stock Number (NSN) 5340-01-323-5
31、523 (Figure 2). Corrosion resistant steel attachment bolts, per NASM90725 , and tab washers will be used to attach the handle to the coupling housing. Tab washers shall be SAE-AS9851 or equivalent. NSN 5340-01-323-5523 FIGURE 2. Handling ring. Provided by IHSNot for ResaleNo reproduction or networki
32、ng permitted without license from IHS-,-,-MIL-DTL-25531F 7 3.6 Locking of parts. All threaded parts shall be locked by safety wiring, by self-locking nuts conforming to MIL-DTL-32258, cotter pin, or other approved methods. Safety wire shall be installed in accordance with NASM33540 and shall conform
33、 to NASM20995. The use of lock washers, set screws or staking is not permitted unless specifically approved by the using service. However, staking shall not be used where failure of the staking will allow any loose part in the flow stream. 3.6.1 Coupling to fitting connection. Provision shall be mad
34、e for positive locking of the hose fitting to the coupling. The lock shall be of a reusable type. 3.7 Performance. The coupling shall function equally well with air flowing in either direction and shall satisfy the applicable requirements when tested in accordance with 4.6. 3.8 Attachment. The force
35、 required to engage the coupling to the nipple shall not exceed 25 pounds. Attachment shall be made by inserting the coupling onto the nipple by virtue of the handling ring (National Stock Number (NSN) 5340-01-323-5523) attached to the coupling collar. The coupling shall be so constructed that in th
36、e unattached position it is ready for instant connection to the aircraft nipple. It shall not be necessary to first retract the sleeve for connection. The coupling shall also be so constructed that it will not become partially locked on the nipple, allowing it to come off during the operation. Pulli
37、ng on the hose normally connected to the coupling shall not result in disengagement of the coupling. 3.9 Release. The coupling shall contain two methods of release from the aircraft nipple, a primary and secondary release. 3.9.1 Primary. Primary release of the coupling shall be in pulling back on th
38、e handling ring and not requiring a force of more than 30 pounds to release the coupling from the aircraft nipple. This release shall leave the coupling in position for the next attachment. 3.9.2 Secondary. In the event the handling ring is not in use, disconnect can be made by simply grasping the c
39、oupling sleeve and pulling it in the reverse direction. If for some reason a lanyard is required such shall be constructed of a chain complying with or equivalent to RR-C-271, Type 1, Grade C, Class 5, Style 2, zinc coated, .15625 (Number 2) size with a T-type handle attached to the free end. End co
40、nnecting links shall be of equivalent welded and zinc coated steel wire. The handle and 2 inch chain adjacent to the handle shall be covered with a heat resistant plastic or rubber covering. 3.9.3 Safety device. An automatic pressure lock and a self-closing automatic mechanical safety valve shall be
41、 provided for safety of operation. The pressure lock shall immobilize the primary and secondary release when the coupling is in the engaged position and under pressure. The pressure lock shall be so located that it is always accessible without disassembly of the coupling for manual deactivation whil
42、e the coupling is connected to the nipple. The automatic pressure lock shall prevent disconnect of the coupling when the pressure is above 10 psi. It shall only be necessary for the valve to sufficiently stop the air flow to prevent danger to operating personnel. The device incorporated shall not be
43、 adversely affected by gravitational forces. Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-DTL-25531F 8 3.10 Interchangeability. All parts having the same manufacturers part number shall be functionally and dimensionally interchangeable. The dr
44、awing number requirements of MIL-STD-31000 shall govern changes in the manufacturers part numbers. 3.11 Dimensions. The dimensions of the coupling shall be as shown in Figure 1. 3.12 Weight. The weight of the coupling shall be the minimum consistent with required performance, but shall not exceed 10
45、 pounds. 3.13 Finishes and protective coatings. 3.13.1 Finishes. The coupling shall have no painted surfaces. 3.13.2 Protective coatings. The coupling shall be adequately protected against corrosion by use of material or protective coatings acceptable to the procuring activity. 3.13.2.1 Anodizing. A
46、ll aluminum-alloy parts shall be anodized in accordance with MIL-A-8625. 3.14 Identification of product. Equipment, assemblies, and parts shall be marked for identification in accordance with MIL-STD-130. 3.15 Workmanship. The coupling shall be uniform in quality, clean, sound, smooth, and free from
47、 injurious defects. 4. VERIFICATION 4.1 Classification of inspections. The inspection requirements specified herein are classified as follows: a. Qualification inspection (see 4.2). b. Conformance inspection (see 4.2). 4.2 Classification of tests. The inspection and testing of the couplings shall be
48、 classified as follows: a. Qualification tests (see 4.3) b. Quality conformance test see 4.4). 4.3 Qualification tests. The qualification tests shall consist of all the tests specified under 4.6 and conducted in the order listed. 4.3.1 Sampling instructions. The qualification test samples submitted
49、for Government tests shall consist of two couplings of each manufacturers part number upon which qualification is desired. Samples submitted shall be accompanied by a report of the completed qualification test and shall Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-DTL-25531F 9 be identified with t
