1、Comments, suggestions, or questions on this document should be addressed to: Commander, Naval Sea Systems Command, ATTN: SEA 05M2, 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 contac
2、t information can change, you may want to verify the currency of this address information using the ASSIST Online database at http:/assist.daps.dla.mil. AMSC N/A FSC 4730 INCH-POUND MIL-DTL-24788A 22 May 2008 SUPERSEDING MIL-C-24788 09 September 1993 DETAIL SPECIFICATION COUPLING ASSEMBLY, SEMI-DRY-
3、BREAK, QUICK-DISCONNECT FUEL WITH OR WITHOUT CONTINUITY SWITCH This specification is approved for use by all Departments and Agencies of the Department of Defense. 1. SCOPE 1.1 Scope. This specification covers the requirements for acquisition of a semi-dry-break, quick-disconnect fuel coupling assem
4、bly, with or without continuity switch used in connecting fueling nozzles to aircraft refueling hoses and refueling pantographs in aircraft refueling systems. 1.2 Classification. Quick-disconnect coupling assemblies are of the following classes, as specified (see 6.2): Class 1 Semi-Dry-Break, Quick-
5、Disconnect Assembly without Continuity Switch Class 2 Semi-Dry-Break, Quick-Disconnect Assembly with Continuity Switch 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 not include documents cited i
6、n 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 sections 3, 4, or 5 of this spe
7、cification, 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 of these documents are thos
8、e cited in the solicitation or contract. Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-DTL-24788A 2 FEDERAL STANDARDS FED-STD-H28 - Screw-Thread Standards for Federal Services DEPARTMENT OF DEFENSE SPECIFICATIONS MIL-PRF-370 - Hose and Hose Ass
9、emblies, Nonmetallic: Elastomeric, Liquid Fuel MIL-PRF-680 - Degreasing Solvent MIL-DTL-5624 - Turbine Fuel, Aviation, Grades JP-4 and JP-5 MIL-PRF-7024 - Calibrating Fluids, Aircraft Fuel System Components MIL-S-8512 - Support Equipment, Aeronautical, Special, General Specification for the Design o
10、f MIL-H-17902 - Hose, End Fittings and Hose Assemblies, Synthetic Rubber, Aircraft Fuels MIL-DTL-83133 - Turbine Fuels, Aviation, Kerosene Types, NATO F-34 (JP-8), and NATO F-35, and JP-8+100 DEPARTMENT OF DEFENSE STANDARDS MIL-STD-130 - Identification Marking of U.S. Military Property (Copies of th
11、ese documents are available online at http:/assist.daps.dla.mil/quicksearch/ or http:/assist.daps.dla.mil or from the Standardization Document Order Desk, 700 Robbins Avenue, Building 4D, Philadelphia, PA 19111-5094.) 2.3 Non-Government publications. The following documents form a part of this docum
12、ent to the extent specified herein. Unless otherwise specified, the issues of these documents are those cited in the solicitation or contract. AMERICAN PETROLEUM INSTITUTE (API) API/IP STD 1529 - Aviation Fuelling Hose and Hose Assemblies (Copies of this document are available online at www.api.org
13、or from API Publications, Global Engineering Documents, 15 Inverness Way East, M/S C303B, Englewood, CO 80112-5776.) ASTM INTERNATIONAL ASTM D1655 - Standard Specification for Aviation Turbine Fuels (DoD adopted) (Copies of this document are available online at www.astm.org or from ASTM Internationa
14、l, 100 Barr Harbor Dr., PO Box C700, West Conshohocken, PA 19428-2959.) INTERNATIONAL ORGANIZATION FOR STANDARDS (ISO) ISO 68-2 - ISO General Purpose Screw Threads, Basic Profile, Part 2: Inch Screw Threads (Copies of this document are available online at www.iso.org or from ISO, 1, rue de Varemb, C
15、H-1211 Geneva 20, Switzerland.) SAE INTERNATIONAL SAE AS5877 - Detailed Specification for Aircraft Pressure Refueling Nozzle (DoD adopted) Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-DTL-24788A 3 (Copies of this document are available online
16、at www.sae.org or from SAE World Headquarters, 400 Commonwealth Drive, Warrendale, PA 15096-0001.) 2.4 Order of precedence. 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, sup
17、ersedes applicable laws and regulations unless a specific exemption has been obtained. 3. REQUIREMENTS 3.1 Qualification. Semi-dry-break, quick-disconnect coupling assemblies (or components) furnished under this specification shall be products that are authorized by the qualifying activity for listi
18、ng on the applicable qualified products list before contract award (see 4.2 and 6.2). 3.2 Components. A complete semi-dry-break, quick-disconnect coupling assembly shall consist of male (otherwise known as nipple) and female (otherwise known as quick-disconnect coupling or coupling) halves. The dry-
19、break feature shall be included within the female (hose) half only. The female half mates to the aircraft refueling hose as depicted in Figure 2. The male half shall mate with the standard SAE AS5877 aircraft pressure fuel nozzle and shall be in accordance with Figure 1. When the male and female hal
20、ves are mated to the nozzle and aircraft refueling hose, respectively, the male and female halves are connected to complete the semi-dry-break, quick-disconnect coupling assembly. FIGURE 1. Requirements for male half of quick-disconnect assembly. Provided by IHSNot for ResaleNo reproduction or netwo
21、rking permitted without license from IHS-,-,-MIL-DTL-24788A 4 3.2.1 Strainers. Strainers shall be 60-mesh screen or as specified by the procuring activity (see 6.2). 3.3 Materials. Materials and processes used by the manufacturer of the dry-break quick-disconnect assemblies shall be suitable for the
22、 intended purpose and shall conform to the applicable specifications listed (see 2.2.1). All wetted components of the quick-disconnect assembly shall be compatible with MIL-DTL-5624, MIL-DTL-83133, and ASTM D1655. 3.3.1 Metals. Metals used in the manufacturing of the assemblies shall be lightweight
23、aluminum alloys or stainless steel suitable for use in a marine environment. All aluminum surfaces shall be protected to resist corrosion. To prevent galvanic action, the use of dissimilar metals in contact with each other shall be minimized. Dissimilar metals in contact with each other must be prot
24、ectively coated. The use of magnesium, manganese, copper, zinc, cadmium, or their alloys (alloys containing more than 5 percent of the subject materials) thereof is prohibited. 3.3.1.1 Component examination. Castings shall be clean, sound, and free of defects that would interfere with components wor
25、king as specified (see 4.4). 3.3.2 Test fluids. Where tests are conducted requiring the use of test fluids, the test fluids shall be in accordance with MIL-PRF-680, MIL-DTL-5624, MIL-DTL-83133, MIL-PRF-7024, or ASTM D1655. 3.4 Design. The female half of the semi-dry-break, quick-disconnect coupling
26、assembly shall not exceed the envelope dimensions or the weight limitations shown on Figure 2. The semi-dry-break, quick-disconnect coupling assembly shall connect or disconnect a hose and nozzle easily by a single person wearing winter gloves without using tools. The semi-dry-break, quick-disconnec
27、t coupling assembly shall consist of a male and a female halve of which the female half shall incorporate an automatically operated mechanism to prevent spillage of liquid from the hose when the units are disconnected. A strainer of specified mesh opening shall be provided between the two halves of
28、the units. The strainer shall be removable from the male half for checking, cleaning, or replacing without the use of tools. All normal replacement parts shall be the same regardless of the thread or inlet size of the unit. The interface seal between the male and female halves shall engage the femal
29、e half immediately when the semi-dry-break in the female half is opened, or immediately thereafter to minimize any fuel leakage during connection. During disconnection, the interface seal between the male and female halves shall disengage immediately when the semi-dry-break in the female half is com
30、pletely closed, or immediately thereafter to minimize any fuel leakage during disconnection. Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-DTL-24788A 5 FIGURE 2. Envelope and weight limitations and contact assembly location. 3.4.1 Control (or c
31、ontinuity) switch. The female half of the semi-dry-break, quick-disconnect coupling assembly, Class 2, shall contain a sealed single pole, single throw control switch. The switch mechanism must be shielded by a protective guard. The top of the switch mechanism shall not extend above the switch guard
32、 so as to prevent abrasion of the switch mechanism, and to prevent inadvertent actuation. One side of the continuity switch shall be electrically connected to the body of the female half of the semi-dry-break, quick-disconnect coupling assembly and the other side of the switch shall be isolated from
33、 the body and shall make electrical contact with the spider assembly protruding from the end of the mating aircraft refueling hose, as shown in Figure 2. 3.4.1.1 Protective boot. The switch mechanism must be sealed by a rubber boot or cover; or be designed to resist deterioration in its performance
34、when subjected to a severe marine environment without a rubber boot or cover. 3.4.2 Commercial standard tools. Design of the semi-dry-break, quick-disconnect coupling assemblies shall enable disassembly, reassembly, and service maintenance to be accomplished by means of commercially standard tools a
35、s defined in MIL-S-8512. 3.5 Construction. Semi-dry-break, quick-disconnect coupling assemblies shall withstand the strains, jars, vibrations, and other conditions incident to shipping, storage, and service usage. The assembly shall withstand a drop of 6 feet onto a steel plate without any damage af
36、fecting operation as specified in 4.5.12. Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-DTL-24788A 6 3.5.1 Strainer. The strainer in a clogged condition shall withstand 15 pounds per square inch (PSI) differential pressure in the fueling direct
37、ion without collapse, tearing, or other damage to the screen. 3.6 Screw threads. Screw threads shall be in accordance with FED-STD-H28 or ISO 68. 3.6.1 Screw-thread locking devices. Threaded fasteners that, if loosened or disengaged, could fall into the fuel system, shall be locked by self-locking n
38、uts, thread locking inserts, lock wires, or cotter pins. 3.7 Synthetic rubber parts. 3.7.1 Elastomeric compatibility. O-rings, seals, and other elastomeric parts shall be compatible with aviation fuels as specified in 3.3.2. 3.7.2 Elastomeric serviceability. Elastomeric parts shall be readily replac
39、eable with a minimum teardown of attaching parts. 3.8 Interchangeability. Parts having the same manufacturers part number shall be directly and completely interchangeable with each other with respect to installation and performance. Regardless of manufacturer, all male halves (nipple), per Figure 1,
40、 shall be completely interchangeable in terms of installation and performance when used with all female halves. 3.9 Identification of product. Assemblies and parts shall be marked for identification in accordance with MIL-STD-130. 3.9.1 Identification. The female half of the semi-dry-break, quick-di
41、sconnect coupling assembly shall be identified in accordance with MIL-STD-130. The information shall contain the following: a. Manufacturers name or logo b. The number of this specification c. Contract or order number d. Manufacturers part number e. Manufacturers serial number f. Date of manufacture
42、 3.10 Performance requirements. 3.10.1 Proof pressure. When tested as specified in 4.5.1, there shall be no evidence of leakage, distortion, or failure of any part or component. 3.10.2 Operating force. When tested as specified in 4.5.2, the force to engage the male and female halves of the semi-dry-
43、break, quick-disconnect coupling assembly shall not exceed 60 pounds and the force to disengage shall not exceed 20 pounds. 3.10.3 Leakage. When tested as specified in 4.5.3, there shall be no evidence of leakage from the semi-dry-break, quick-disconnect coupling assembly under positive pressure. Wh
44、en under negative pressure leakage of air into the semi-dry-break, quick-disconnect coupling assembly shall not be greater than 50 cubic centimeters (cc) per minute. 3.10.3.1 Semi-dry-break leakage. When tested as specified in 4.5.3.1, there shall be no leakage through the female half of the semi-dr
45、y-break, quick-disconnect coupling assembly. 3.10.4 Extreme temperature. When tested as specified in 4.5.4, there shall be no signs of leakage, cracking, or other evidence of failure to the semi-dry-break, quick-disconnect coupling assembly. 3.10.5 Total pressure loss. When tested as specified in 4.
46、5.5, the pressure drop across the entire semi-dry-break, quick-disconnect coupling assembly shall not be greater than 12 PSI at 300 gallons per minute (gal/min). Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-DTL-24788A 7 3.10.6 Strength. When t
47、ested as specified in 4.5.6, there shall be no damage which causes malfunctioning of the semi-dry-break, quick-disconnect coupling assembly, nor shall there be any leakage exceeding one drop per minute. 3.10.7 Angular movement. When tested as specified in 4.5.7, there shall be no damage which causes
48、 malfunctioning of the semi-dry-break, quick-disconnect coupling assembly, nor any visible external leakage. 3.10.8 Endurance, wet and dry. When tested as specified in 4.5.8.1 and 4.5.8.2, the semi-dry-break, quick-disconnect coupling assembly shall pass the operating force test and leakage tests, a
49、s specified in 4.5.8.1 and 4.5.8.2. 3.10.9 Electrical resistance. When tested as specified in 4.5.9, the electrical resistance across the semi-dry-break, quick-disconnect coupling shall be less than or equal to 10.0 ohms. 3.10.10 Insulation breakdown. When tested as specified in 4.5.10, there shall be no insulation breakdown either during or as a result of the test. 3.10.11 Accelerated corrosion. When tested a
