1、_ SAE Technical Standards Board Rules provide that: “This report is published by SAE to advance the state of technical and engineering sciences. The use of this report is entirely voluntary, and its applicability and suitability for any particular use, including any patent infringement arising there
2、from, is the sole responsibility of the user.” SAE reviews each technical report at least every five years at which time it may be revised, reaffirmed, stabilized, or cancelled. SAE invites your written comments and suggestions. Copyright 2015 SAE International All rights reserved. No part of this p
3、ublication may be reproduced, stored in a retrieval system or transmitted, in any form or by any means, electronic, mechanical, photocopying, recording, or otherwise, without the prior written permission of SAE. TO PLACE A DOCUMENT ORDER: Tel: 877-606-7323 (inside USA and Canada) Tel: +1 724-776-497
4、0 (outside USA) Fax: 724-776-0790 Email: CustomerServicesae.org SAE WEB ADDRESS: http:/www.sae.org SAE values your input. To provide feedback on this Technical Report, please visit http:/www.sae.org/technical/standards/MAP2261 AEROSPACE RECOMMENDED PRACTICEMAP2261 Issued 1993-06 Reaffirmed 2015-08 F
5、luid Couplings for Spacecraft Servicing, Preparation of Specification for, Metric RATIONALE MAP2261 has been reaffirmed to comply with the SAE five-year review policy. 1. SCOPE:This SAE Metric Aerospace Recommended Practice (MAP) establishes the requirements forpreparing a specification for fluid co
6、uplings for spacecraft servicing. The objective of this document isto provide design, development, verification, storage, and delivery requirement guidelines for thepreparation of specifications for fluid couplings and the ancillary hardware for use with serviceablespacecraft designed for use in the
7、 space environment. The couplings shall be capable of resupplyingstorable propellants, cryogenic liquids, and gases to a variety of spacecrafts.1.1 Product Classification:The couplings shall be classified as follows:a. Type I: Tanker halfb. Type II: Spacecraft half1.1.1 The Type I coupling shall be
8、attached to the supply tanker. This half shall contain the majority of the seals and mechanical/electrical complexity.1.1.2 The Type II coupling shall be attached to the spacecraft. This half shall contain fewer seals and less mechanical/electrical complexity in order to maximize reliability.1.2 Usa
9、ge Classification:The couplings shall be classified by usage such as robotic, automated, and manual.SAE INTERNATIONAL MAP2261 Page 2 of 14 2. REFERENCES:2.1 SAE Publications:Available from SAE, 400 Commonwealth Drive, Warrendale, PA 15096-0001.AIR4728 References, Spacecraft and Servicing (Abbreviati
10、ons, Acronyms, Definitions, Applicable Documents and Environmental Conditions)SAE Technical Report Style Manual2.2 Abbreviations and Acronyms:Standard abbreviations and acronyms used in this document and frequently used in aerospace technical documents are given in AIR4728.2.3 Definitions:Definition
11、s of terms used in this document and frequently used in aerospace technical documents are given in AIR4728.3. REQUIREMENTS:3.1 Preparation of Specifications:A specification prepared in accordance with this MAP shall be presented using the rules given for specifications in the SAE Technical Report St
12、yle Manual (see Section 6 through 6.6.5).3.2 Technical Requirements:The following design requirements (physical/performance/environmental) statements shall be considered for inclusion and may be specified in a fluid coupling specification to support fluid servicing and space assembling in a space en
13、vironment.3.2.1 Examples of Physical Requirements: Following are physical requirements that shall be considered for listing in the specification. Only requirements applicable to the product and usage classification are to be included. Examples of wording for each paragraph are presented.3.2.1.1 Enve
14、lope: The fluid coupling envelope shall conform to the applicable procuring agency dimensions.3.2.1.2 Mounting: The fluid coupling shall be designed to engage and disengage with the system components as indicated on the part standard drawing.SAE INTERNATIONAL MAP2261 Page 3 of 14 3.2.1.3 Weight: As
15、a design goal, the combined weight of both coupling halves shall not exceed the weight indicated by the procuring agency including any caps, covers, or unique supporting equipment, that must remain attached to the coupling or spacecraft/tanker.3.2.1.4 Materials: The fluid coupling shall be construct
16、ed of materials that will not change the composition of, or be adversely affected by the fluid medium, environment, or service life specified.3.2.1.5 Design and Construction: The configuration, dimensions, and other design details shall comply with the requirements in the part standard drawing. Mech
17、anical units of the dimensions in the part standard drawing shall comply with the requirements and recommendations of the International System of Units (SI). Equivalent dimensions using units in accordance with the British Engineering System shall follow the SI dimensions and shall be enclosed in pa
18、rentheses. The design objective shall be to obtain the smallest size and lightest weight commensurate with meeting performance requirements. The coupling design shall preclude occurrence of a catastrophic hazard. Structural integrity of the coupling design shall preclude cumulative creep or strain l
19、eading to rupture or permanent deformation that would affect the service life of the coupling.3.2.1.6 Seals: All seals used in the coupling design shall be replaceable either independently or as a seal assembly unit, without cutting coupling or cover welds. All seals shall be designed and certified
20、for full life without maintenance. Seal replacement is for contingency purposes only and not scheduled maintenance. All critical interface seals shall be located on the tanker half of the coupling to permit ease of checkout and replacement.3.2.1.7 Interchangeability: Couplings of the same part numbe
21、r shall be interchangeable in accordance with the definition in MIL-STD-280. This includes like assemblies, subassemblies, and replaceable parts.3.2.1.8 Protective Covers:3.2.1.8.1 Manual Coupling: If required by the part standard drawing, covers shall be required for each demated coupling half as a
22、 means of protecting all exposed critical surfaces, seals, etc. from damage and to minimize the entry of contaminants. Each cover shall be tethered to its respective half.3.2.1.8.2 Automated Coupling: Covers for automated couplings shall be provided by the host mechanism and are, thus, outside the s
23、cope of this document.3.2.1.9 Filter Elements: If required by the part standard drawing, the fluid flow path of the tanker half (Type I) and the spacecraft half (Type II) shall incorporate filter elements. The filter elements shall be located to prevent the entry of contamination.3.2.1.10 Filter Rat
24、ing: The filter elements in the fluid flow path in either direction shall incorporate a micron particle rating as defined in the part standard drawing consistent with protecting the design of the coupling and system.SAE INTERNATIONAL MAP2261 Page 4 of 14 3.2.1.11 Launch Vehicle Safety: The coupling
25、shall comply with the applicable safety requirements of launch and transporation vehicles in both the mated/demated positions, and during all operational phases associated with its use.3.2.1.12 Fluid Flow Path: The coupling shall be designed to allow the maximum fluid flow in the direction of flow r
26、esulting in uniform flow area based on tube size and minimum turbulance.3.2.1.13 Flow Control: As required by the specific application, flow through the fluid path shall be provided by flow control devices in each coupling half. Actuation of the flow control devices to the open position may be accom
27、plished during the mating process or independent of the mating process. In either case, the flow control device must be actuated to the closed position prior to demating the interface seals and must not actuate to the open position prior to mating the interface seals or after separation of the Type
28、I/Type II interface.3.2.1.14 Engagement and Disengagement: As required by the specific application, the coupling shall be designed for either automatic or manual mating and demating. The engagement and disengagement processes shall require two separate phrases: first, latching to resist pressure sep
29、aration, and second, opening to permit fluid flow.3.2.1.15 Failure Tolerant:3.2.1.15.1 Critical Hazards: Critical hazards shall be controlled such that no single failure or operator error can result in damage to launch equipment, a nondisabling personnel injury, or the use of unscheduled safing proc
30、edures that affect operations.3.2.1.15.2 Catastrophic Hazards: Catastrophic hazards shall be controlled such that no single or combination of two failures or operator errors can result in the potential for a disabling or fatal personnel injury or loss of the launch vehicle, ground facilities, or equ
31、ipment.3.2.1.16 Position Indicators: The coupling shall be designed with appropriate indicators to provide indication that the coupling has been fully coupled or decoupled and, consequently, shows the status of the fluid flow path.3.2.1.17 Pressure Buildup: The coupling shall be designed to limit pr
32、essure buildup of trapped volumes of fluid medium between all seals and between all flow control devices during any stage of use whether mated/demated. The pressure buildup allowed before relief shall not degrade the performance of the coupling. Unless otherwise specified, no external venting to spa
33、ce shall be permitted.3.2.1.18 Use of Standard Parts: Standard parts shall be used in the design of the fluid coupling to the greatest degree possible.3.2.1.19 Indexing (Keying): The coupling shall incorporate an indexing feature to prevent mating with other coupling part numbers and/or with the sam
34、e coupling part number for different fluids used at different locations.SAE INTERNATIONAL MAP2261 Page 5 of 14 3.2.1.20 Maintainability: The coupling shall be designed so that maintenance, overhaul, or adjustment during its operating life can be accomplished on the Type II spacecraft half.3.2.1.21 F
35、ailure Deterrent: The coupling shall be designed such that:a. Built-in liquid traps, which would cause malfunction or failure, shall be eliminated.b. Blind pockets, where hidden corrosion could develop, shall be prohibited.c. Failure propagation protection shall be provided such that transient out-o
36、f-tolerance conditions or component failures shall not cause other component or subsystem failures.d. Positive locking on threaded parts and fasteners shall be incorporated to prevent loosening during service. The use of safety wire shall be prohibited.e. Backward or improper installation of unidire
37、ctional components or piece parts shall be prevented by use of nonsymmetry of configuration, different connecting sizes, or other comparable means.f. Sliding fits shall be designed to preclude frictional failures and/or binding.g. Fatigue failure resulting from flow-induced vibrations in flexible se
38、ctions shall be prevented by proper design practices and material selection.3.2.1.22 Protective Treatment: Materials subject to deterioration, when exposed to climatic and other environmental conditions as specified, shall be protected against such deterioration. The method of protection shall not p
39、revent compliance with other requirments of the specification. The use of any protective coating that will crack, chip, scale, or erode during the required life when exposed to the extremes of climatic, environmental, or operational conditions specified, shall be prohibited.3.2.1.23 Identification:
40、Parts and assemblies shall be marked for identification in accordance with the specification.3.2.1.24 Lubricants: The use of lubricants shall be discouraged. If their use is necessary, lubricants shall meet prior approval by the procuring agency.3.2.1.25 Outgassing: Materials used shall be suitable
41、for use in a space environment, exhibit low outgassing characteristics, and maintain their mechanical, physical, and electrical properties over the shelf and operational life times.3.2.1.26 Workmanship: All parts and assemblies shall be designed, produced, and tested in a quality manner intended to
42、produce defect-free hardware.SAE INTERNATIONAL MAP2261 Page 6 of 14 3.2.2 Examples of Performance Requirements: Performance requirements are to be presented in the specification to establish the characteristics necessary for the coupling to completely satisfy system operating conditions. Realistic l
43、imits and tolerances shall be provided to permit economic design and manufacturing practices. Following are performance requirements that shall be considered for listing in the specification. Examples of wording for each paragraph are presented.3.2.2.1 Fluid Medium: The coupling shall meet all requi
44、rements while internally pressurized with the working fluid and shall also be capable of meeting all the requirements after exposure to the referee or cleaning fluid used. The following is a representative list of working and referee fluids and their specifications:a. Hydrazine per MIL-P-26536 (prop
45、ellant)b. Gaseous helium per MIL-P-27407 (pressurant)c. Gaseous nitrogen per MIL-P-27401 (pressurant)d. Distilled and deionized water (cleaning/referee)e. Isopropyl alcohol per TT-I-735, Grade A (cleaning/referee)f. Trichlorotrifluoroethane per MIL-C-81302 (cleaning/referee)g. Liquid nitrogen per MI
46、L-P-27401 (coolant)h. Liquid oxygen per MIL-P-25508 (propellant)i. Monomethylhydrazine per MIL-P-27404 (propellant)j. Nitrogen tetroxide per MIL-P-26539 (propellant)k. Liquid hydrogen per MIL-P-27201 (propellant)l. Anhydrous ammonia, technical per O-A-445 (coolant)m. Fluorocarbon refrigerants per BB
47、-F-1421 (cleaning/referee)n. Superfluid helium per MIL-P-27407 (coolant)3.2.2.2 Operating Temperature Range: The coupling shall be designed to operate throughout the specified minimum and maximum temperature range.3.2.2.3 Nonoperating Temperature Range: The fluid coupling shall show no malfunction a
48、fter being subjected to extreme temperature conditioning from the specified maximum to minimum temperatures.3.2.2.4 Rated Pressure: The maximum internal pressure to which the mated/demated coupling will be exposed shall be specified.3.2.2.5 Surge Pressure: If applicable, the coupling shall be design
49、ed to withstand pressure surge cycles specified over the life of the coupling without any structural damage or degradation. A 50 to 100% performance margin is recommended.3.2.2.6 Proof Pressure: The proof pressure shall be not less than 150% and not more than 200% of the rated pressure in accordance with specified program requirements.3.2.2.7 Burst Pressure: The burst pressure shall not be less than 250% and not more than 400% of the rated pres
