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 2013 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/AIR1664A AEROSPACE INFORMATION REPORT AIR1664 REV. A Issued 1990-01 Revised 1996-
5、10 Reaffirmed 2013-08 Superseding AIR1664 Aircraft Flexible Tanks General Design and Installation Recommendations RATIONALE AIR1664A has been reaffirmed to comply with the SAE five-year review policy. TABLE OF CONTENTS1. SCOPE. 31.1 Purpose 32. REFERENCES. 32.1 Applicable Documents 32.1.1 Nonself-Se
6、aling Specifications . 32.1.2 Self-Sealing Specifications . 42.1.3 Other Related Documents 42.2 Glossary. 43. BACKGROUND 64. DESIGN RECOMMENDATIONS 74.1 Tank Configuration. 84.2 Tank to Structure Support (Hangers) 84.3 Plumbing Adapter Fittings 114.3.1 Nipple Type Fittings114.3.2 Bolting Ring Type F
7、ittings.134.3.3 Fitting/Structure-Interface.184.4 Tank/Structure Interface.184.5 Cavity Configuration and Preparation.214.6 Backing Board304.7 Manufacturing Tolerances/Fit .304.8 Vulnerability/Survivability Considerations314.9 Fluid Slosh Attenuation.325. TANK WEIGHT - ESTIMATING FOR DESIGN 326. TAN
8、K MARKING 347. TANK REPAIR .34TABLE OF CONTENTS (Continued)FIGURE 1 Recommended Proportions for Convolutions. 9FIGURE 2 Typical Crash-Resistant Tank Fitting Bolt Center Line to Mold Line Distance14FIGURE 3 Recommended Dimensions for Fuel Tank Fabrication.15FIGURE 4 Installation Procedure 19FIGURE 5
9、Fitting/Structure - Interface 22FIGURE 6 Installed Tanks Showing Lacing.23FIGURE 7 Typical Self-Sealing Tank Installation 25FIGURE 8 Ballistic Penetration of Self-Sealing Tank Installation 26SAE INTERNATIONAL AIR1664A Page 2 of 34_ 1. SCOPE:This SAE Aerospace Information Report (AIR) includes genera
10、l information about the various typesand styles of flexible tanks and the tank-mounted fittings that adapt the tank to the surroundingstructure and fluid-system plumbing.Recommendations are given relative to the dimensional layout of the tank when theserecommendations serve to avoid tank fabrication
11、 problems and tank/structure interface problems. As a part of these recommendations, critical dimensions of plumbing adapter fittings are discussedand recommendations made. Tank manufacturing tolerances are given.Recommendations are made relative to cavity design and preparation to facilitate a reli
12、ableinstallation.The special installation requirements of nonself-sealing, self-sealing, and crash-resistant tanks arediscussed.This document is not intended to replace the information or requirements of the military andcommercial procurement specifications listed in Section 2. No attempt has been m
13、ade, except in avery general way, to include physical property data such as weight and thickness of the compositematerials available in the industry. Such materials are too numerous and vary too much betweenmanufacturers.Whenever specific data or advice is required, it is necessary that the tank man
14、ufacturers beconsulted.1.1 Purpose:The purpose of this document is to supply aircraft fluid-system designers with baselineinformation pertinent to the application of flexible, removable tanks for power plant fluids withoutregard to the fluid in the tank.2. REFERENCES:2.1 Applicable Documents:The fol
15、lowing publications form a part of this document to the extent specified herein. The latestissue of SAE publications shall apply. The applicable issue of each publication shall be that ineffect on the date of this AIR unless otherwise specified in the manufacturers modelspecification. In the event o
16、f conflict between the text of this document and references citedherein, the text of this document takes precedence. Nothing in this document, however,supersedes applicable laws and regulations unless a specific exemption has been obtained.2.1.1 Nonself-Sealing Specifications:MIL-T-6396 Tanks; Fuel,
17、 Oil, Water Alcohol Coolant Fluid, Aircraft, Nonself-Sealing,Removable, InternalTSO-C80 Federal Aviation Agency Standard - Flexible Fuel and Oil Cell MaterialSAE INTERNATIONAL AIR1664A Page 3 of 34_ 2.1.2 Self-Sealing Specifications:MIL-T-5578 Tank; Fuel, Aircraft, Self-SealingMIL-T-27422 Tank; Fuel
18、, Crash Resistant Aircraft (Nonself-Sealing and Self-Sealing)2.1.3 Other Related Documents:MIL-C-5040 Cord, NylonMIL-C-5541 Chemical Conversion Coatings on Aluminum and Aluminum AlloysMIL-P-8045 Plastic, Self-Sealing and Nonself-Sealing Tank Backing MaterialMIL-B-83054 Baffle Material and Inerting,
19、Aircraft Fuel TankMIL-F-87260 Foam Material, Explosion Suppression, Inherently Electrically Conductive,For Aircraft Fuel Tank and Dry Bay AreasMIL-STD-801 Acceptance Standards for Flexible TanksMIL-STD-1290 Light Fixed and Rotary Wing Aircraft CrashworthinessMIL-STD-1472 Human Engineering Design Cri
20、teria for Military Systems, Equipment andFacilitiesMS29558 Tank Fitting “O“ Ring - Center BoltMS29559 Tank Fitting “O“ Ring - Through HoleMS29560 Tank Fitting “O“ Ring - Threaded HoleTM-78-08 USAF Technical Memorandum - Foam DesignTR-89-D22E USAAVSCOM Aircraft Crash Survival Design Guide Vol. V - Ai
21、rcraft PostCrash SurvivalAIR1662 Minimization of Electrostatic Hazards in Aircraft Fuel SystemsAIR4170 Reticulated Polyurethane Foam Explosion Suppression Material for FuelSystems and Dry BaysAS4873 Gland Design, Elastomeric O-ring Seals, Static Radial and Face, 800 psi,Maximum ServiceFAR Part 23 Ai
22、rworthiness Standards: Normal, Utility, Acrobatic, and Commuter CategoryAirplanes2.2 Glossary:BARRIER: A barrier is a film or material applied to the tank inner liner that resists fluidpermeation. Used on nonself-sealing and self-sealing fluid tanks containing aviation fuels.BUILDING FORM: A male sh
23、ape duplicating the shape of the finished tank. The various plies ofrubber-coated fabric or spray-on polyurethane are fabricated over this shape. The formmaintains the tank shape during vulcanization and is removed after vulcanization.CONVOLUTION: Generally, a recess projecting into the tank surface
24、 to clear structural ribs,formers, longerons, etc. Convolutions permit utilization of the maximum volume of the structurefor fluid storage.SAE INTERNATIONAL AIR1664A Page 4 of 34_ 2.2 (Continued):CRASH-RESISTANT TANK: A variation of either a nonself-sealing tank or self-sealing flexibletank fabricat
25、ed of very strong elastomer coated fabric and high-strength fittings. It is intendedthat this tank retain fluid without leakage under impact-survivable crash conditions. This type oftank is procured to MIL-T-27422 for military applications and to the airframe designersspecifications supplemented by
26、TSO-C80 for commercial applications.FIT CHECK FIXTURE: A fixture accurately simulating the size and shape of the aircraft flexibletank cavity. It is used as a quality assurance acceptance test tool.FITTINGS - TANK MOUNTED: Fittings are subassemblies fabricated into the tank wall for thepurpose of:a.
27、 Attaching the tank to structureb. Providing a sealing surface for and a means of attaching equipment items to the tankc. Providing for the attachment and sealing of vent lines and fluid flow lines to the tankThey are an integral part of the tank assembly. Fittings generally consist of metal rings.
28、See“Nipple Fitting.“FITTING FLANGE: Some fitting subassemblies are attached to the flexible tank wall by means ofplies of rubber-coated fabric or molded rubber that are called flanges. These flanges are bondedto the metal rings of the fitting and also to the tank wall and become an integral part of
29、the tankassembly during vulcanization.FIBER-LOCK FITTING: This is a fitting design developed under the auspices of the U.S. Armyspecifically for crash-resistant tanks. It uses numerous individual fibers fabricated radially into thetank wall as means of retaining the metal fitting in the tank. See al
30、so Wedge-Lock forcrash-resistant fittings.HANGER FITTINGS: Various designs of fittings have single bolts, fabric loops, and formed wirerings which are fabricated into the flexible tank wall. Generally, they provide a means ofexternally attaching or supporting the flexible tank to the aircraft struct
31、ure. However, the term isalso applied to fittings used on the inside of the tank to support items of equipment and fluid flowlines.HYDRODYNAMIC RAM: Hydrodynamic ram refers to the pressure loads that develop in a fluidfilled tank as a result of shock loading or the penetration and travel of a projec
32、tile through thefluid. The loads can be such as to cause structural failure.LACE LINE: A high-strength, nylon cord used to support a flexible tank to the structure. It isused in conjunction with attach point on the external surface of the cell and on the structure. Thetype of material is parachute s
33、hroud line procured to MIL-C-5040 Type III.SAE INTERNATIONAL AIR1664A Page 5 of 34_ 2.2 (Continued):LINER (INNER LINER): The innermost ply of a flexible fluid tank. It can be either a rubber layer,a rubber-coated fabric, or a spray-on polyurethane.MOLDED IN PLACE SEAL: A proprietary commercial seali
34、ng gasket in which a partial O-ring ismolded and retained in grooves positioned on both sides of a thin metal ring. The metal ring isdesigned to be installed in the interface of the tank mounted fitting and the structure or item ofequipment.NIPPLE FITTING: A fitting generally molded entirely of rubb
35、er but can contain fabric. The fittingconsists of a tubular section whose inside diameter is sized to match standard aluminum tubing. A seal is obtained using a hose clamp assembled to the outside of the molded tube. The moldedtube may extend outwardly or inwardly from the tank external surface. The
36、 tubular section isadapted to the flexible tank by means of molded flanges. This type fitting is used primarily ingeneral aviation nonself-sealing tanks.NONSELF-SEALING TANK: A tank having no ballistic sealing properties. It can, however,possess tear-resistant characteristics. These tanks are procur
37、ed to MIL-T-6396, MIL-T-27422and commercially modified MIL-T-27422/TSO-C80 specifications.RETICULATED FOAM: A three-dimensional, net-like, open-cell material, made of a flexiblepolyurethane compound. It is useful for explosion suppression and slosh attenuation in aircraftfluid tanks. Procured to MIL
38、-B-83054 or MIL-F-87260. Design with reference to USAF TechnicalMemorandum ASD/AENFEF-TM-78-08 and AIR4170.SCUFF PATCH OR PAD: An additional thickness of material designed to prevent tank walldamage from any anticipated source. The material can be rubber-coated fabric or molded rubberapplied to eith
39、er the inside or outside surface of the tank. Also may be called a wear patch.SELF-SEALING TANK: A tank in which construction is such that an automatic sealing actionoccurs when penetrated by a projectile. The weight and thickness of constructions is adjusted tothe ballistic threat anticipated for t
40、he aircraft. These tanks are procured to MIL-T-5578 orMIL-T-27422.WEDGE LOCK FITTING: A fitting design developed under the auspices of the U.S. Armyspecifically for use in crash-resistant fuel tanks. The fitting gains its name from the use of awedging action to retain the metal fitting rings to the
41、flexible tank materials.3. BACKGROUND:The primary function of a flexible tank, regardless of any subclassification of types, is to provide ameans for fluid storage. After it has been determined that a flexible, removable tank will be used,the airframe fluid system designer will determine the type of
42、 flexible tank that will satisfy therequirements.SAE INTERNATIONAL AIR1664A Page 6 of 34_ 3. (Continued):Since there are limits to the configurations that can be fabricated, it is necessary that consultationwith the tank manufacturers be established early in the design stages to avoid unacceptablede
43、signs.Flexible tanks are generally classified in terms of their secondary functional capability. Thesesecondary capabilities supplement the primary function of fluid storage. Typical secondarycapabilities are self-sealing ability, crash resistance, high temperature resistance, and tearresistance. Ap
44、propriate performance type procurement specifications are available for each ofthese basic types as noted in Section 2.Vulnerability/survivability studies are helpful in determining the type tank (i.e., self-sealing,nonself-sealing, tear-resistant) and the necessity for inerting materials. For weigh
45、t savings, someinstallations use tanks with a combination of self-sealing and nonself-sealing materials. This typetank is procured to specification MIL-T-5578, Protection Levels C or D, or MIL-T-27422, ProtectionLevel B.A flexible tank is essentially a handmade article and is therefore relatively ex
46、pensive. Experienceindicates that the more complex a configuration becomes, the more costly it is in terms of unit cost.Reliability and maintainability can be compromised by excessive complexity in the total design.Materials utilizing nitrile elastomers and polyamide fabrics are commonly used constr
47、uctionmaterials for flexible tanks. These materials have been used since the early 1950s and have noserious shortcomings even though the operating environment of military aircraft is varied andsevere. Compounds of urethane and polyester fabrics are also commonly used in both military andcommercial flexible tanks. For special applications, fluorocarbon elastomers, as well as aramidfabrics, have been used.4. DESIGN RECOMMENDATIONS:The following recommendations apply to nonself-sealing tanks procured to MIL-T-6396,MIL-T-27422, and TSO-C80 and self-sealing tanks
