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/AIR825/12A AEROSPACE INFORMATION REPORT AIR825/12 REV. A Issued 2002-03 Revised 2
5、003-03 Reaffirmed 2013-12 Superseding AIR825/12 Oxygen System Integration and Performance Precautions RATIONALE AIR825/12A has been reaffirmed to comply with the SAE five-year review policy. FOREWORDThis document is one of a set of related documents. These documents comprehensively address the “Intr
6、oduction to Oxygen Equipment for Aircraft“, and are referred to as slash (/) documents, rather than chapters. The documents may be obtained as a set or individually. As the field of oxygen systems for aircraft has evolved, it became cumbersome for one document to cover the full range of subject matt
7、er. The reader who is seeking overall familiarity with oxygen systems for aircraft should read all of these documents that combine to form a general reference to oxygen systems. The reader who is familiar with oxygen systems for aircraft may want to obtain only the slash documents that pertain to to
8、pics that are of specific interest.The document set is written as an introductory level, suitable for anyone who would like to understand the basics of oxygen systems in aircraft, and specifically for the engineer who has just recently been assigned to aircraft oxygen systems. Many of these document
9、s point the reader toward more detailed treatments located in other SAE documents.TABLE OF CONTENTS1. SCOPE .32. REFERENCES .32.1 Applicable Documents .32.2 Definitions 43. DESIGN OBJECTIVES.44. GENERAL INSTALLATION PRINCIPLES 54.1 Location of Dispensing Equipment 54.2 Number and Type of Fittings -
10、Locations .54.3 Support for Oxygen Lines 5TABLE OF CONTENTS (Continued)4.4 Proximity to Combustibles64.5 Proximity to Moving Aircraft Parts64.6 Proximity of Plumbing to Electrical Wiring64.7 Design Precautions74.8 Use of Dissimilar Materials.74.9 Conduction of Electric Current .74.10 Reverse Electri
11、c Currents 74.11 Electrical Bonding 74.12 Tubing Markings.84.13 Tubing Elongation 85. MANUFACTURING STANDARDS86. SAFETY REQUIREMENTS87. HANDLING INSTRUCTIONS .97.1 General Equipment Handling.97.2 Pre-Installation Cleaning97.3 Oxygen Masks .107.4 Oxygen Cylinders.118. MAINTENANCE AND INSPECTION METHO
12、DS .118.1 Oxygen System Maintenance 118.2 Inspections.128.3 Aviation Breathing Oxygen Cylinders and Valves 128.4 Oxygen Cylinders and Systems - Recharging .138.5 Maintenance Intervals149. NOTES149.1 Keywords .14SAE INTERNATIONAL AIR825/12A Page 2 of 14_ 1. SCOPE:Oxygen system integration and perform
13、ance precautions are in particularly dependent on applicable sections of airworthiness requirements per FAR/JAR 25. In this document information will be provided on common principles and good practices regarding design criteria, installation, manufacturing, safety aspects and system handling during
14、maintenance and inspection.2. REFERENCES:2.1 Applicable Documents:The following publications form a part of this document to the extent specified herein. The latest issue of SAE publications shall apply. The applicable issue of other publications shall be the issue in effect on the date of the purch
15、ase order. In the event of conflict between the text of this document and 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.2.1.1 SAE Publications: Available
16、 from SAE, 400 Commonwealth Drive, Warrendale, PA 15096-0001.AIR825/13 Guide for Evaluating Combustion Hazards in Aircraft Oxygen SystemsAS861 Minimum General Standards for Oxygen SystemsAIR1059 Transfilling and Maintenance of Oxygen CylindersAIR1176 Oxygen System and Component Cleaning, PackagingAI
17、R1390 Convenient Location of Oxygen Masks for Both the Crew and Passengers of AircraftAIR1398 Testing of Oxygen EquipmentARP1532 Oxygen System Installation and FabricationAS8010 Aviators Breathing Oxygen Purity Standard2.1.2 FAR Publications: Available from Federal Aviation Administration, 800 Indep
18、endence Avenue, SW, Washington, DC 20591.FAR/JAR 25 Airworthiness RequirementsFAR 232.1.3 CGA Publications: Available from Compressed Gas Association, 4221 Walney Road, 5th Floor, Chantilly, VA 20151-2823.CGA No. 540 CGA Pamphlet V I, American National, Canadian and Compressed Gas Association Standa
19、rd for Compressed Gas CylinderCylinder Valve Outlet Connection for OxygenSAE INTERNATIONAL AIR825/12A Page 3 of 14_ 2.1.4 U.S. Government Publications: Available from DODSSP, Subscription Services Desk, Building 4D, 700 Robbins Avenue, Philadelphia, PA 19111-5094.AFGS-87226A U.S. Air Force Guide Spe
20、cification for Oxygen Systems, Aircraft, General Specification forMIL-STD-4642.1.5 RTCA Publications: Available from RTCA Inc., 1140 Connecticut Avenue, NW, Suite 1020, Washington, DC 20036.RTCA/DO-160D Environmental Conditions and Test Procedures for Airborne Equipment2.2 Definitions:SYSTEM INTEGRA
21、TION AND PERFORMANCE PRECAUTIONS: Measures to be considered by system design, manufacturing, installation, handling, maintenance and inspection to ensure system performance is in compliancewith applicable airworthiness requirements.3. DESIGN OBJECTIVES:Oxygen systems shall comply with regulations, s
22、pecifications and recommendations as applicable to a whole system or subsystems and components.Performance to be provided shall meet particular airworthiness requirements of FAR/JAR 25.1439 - 1453.Environmental conditions such as:- Temperature- Altitude/pressure-Humidity- Rain-condensation- Mechanic
23、al vibration- Shocks- Constant acceleration- Fungus- Pollution- Explosive environment- Magnetic effect- Hermeticity- Hazardous elements- Susceptibility to high, radiation and conduction frequencies- Lightning strike protection-Fire- Sand and dustSAE INTERNATIONAL AIR825/12A Page 4 of 14_ 3. (Continu
24、ed):shall to be taken into account to ensure safe system function under any foreseeable operational condition. Where necessary, redundancies shall be incorporated to satisfy the requirements of an emergency system. For immediate availability and use, a system should be equipped with its own control
25、and indication devices.Dependencies and interfaces to other aircraft systems should be minimized to avoid undesirable impacts on system function.In designated engine burst areas practical design measures should be taken to minimize, on the basis of good engineering judgment, the risk of system damag
26、e due to non-contained engine rotor debris.4. GENERAL INSTALLATION PRINCIPLES:4.1 Location of Dispensing Equipment:Oxygen dispensing equipment shall be located within easy reach of the users according to recommendations of AIR1390 and FAR/JAR 25.1447.4.2 Number and Type of Fittings - Locations:The n
27、umber of fittings should be kept to a minimum. Their location should allow easy inspection. Enough space must be provided to torque the fittings tight.On tubings of a gaseous system only one connection type shall be used. Combination between flared and flareless fitting ends within a specifically de
28、fined system must be avoided.The oxygen system must be leak tested after final installation.All fittings must be located such that any escaping oxygen will not lead to appreciable accumulation of oxygen inside electronic racks or compartments. The fittings of the oxygen system should not be installe
29、d directly adjacent to fittings of fuel, oil or hydraulic systems.4.3 Support for Oxygen Lines:4.3.1 Rigid Tubes: Oxygen lines must be supported by clamps that prevent excessive line movement during aircraft flight and shall have adequate protection against chafing. Vibration isolator clamps are rec
30、ommended where vibration is considered excessive to prevent lines from cracking or fracturing. Isolators minimize fatigue or fracture to oxygen lines from forces of flight. Ensure adequate space is provided to prevent lines touching aircraft structure or components. Supporting of oxygen lines on air
31、craft parts that are dislocated during maintenance actions shall be avoided.SAE INTERNATIONAL AIR825/12A Page 5 of 14_ 4.3.2 Flexible Hose: Careful installation is most important to obtain long life from a flexible hose. Therefore, the location of supports shall ensure that:- On the bends of the fle
32、xible hose no clamps will be used, preventing the movement of the flexible hose during tube elongation.- No reciprocal contact between flexible hoses should occur.- An uncontrolled oscillation of the flexible hoses can not occur.- Motion always takes place in one plane.- Care should be taken not to
33、twist the hose while tightening.4.4 Proximity to Combustibles:Oxygen lines and supply components shall not be mounted below other lines or tanks that contain combustible fluids that could leak onto the oxygen tubing. In particular, no fuel, oil or hydraulic fitting shall be above or adjacent to any
34、oxygen tube fitting(s) or component.Accordingly parts of an oxygen system should be above and at least 150 mm (6 in) away from fuel, oil and hydraulic systems or areas where leakage of combustibles can collect. If, for design reasons, it is not possible to maintain the above mentioned minimum cleara
35、nce, then the oxygen line shall be covered by a protective sleeve. Deflector plates should also be used to keep liquids (including high pressure spray) away from oxygen lines, fittings and equipment.4.5 Proximity to Moving Aircraft Parts:There should be at least a 50 mm (2 in) clearance at maximum p
36、oint of movement or deflection between oxygen plumbing and equipment components and any moving aircraft parts. If this minimum clearance is not achievable, the oxygen line must be shielded against mechanical damage by assuming the worst load factors for the shield.Particular attention should be paid
37、 to clearance to primary flight and engine controls where the distance should not be less than 12 in.4.6 Proximity of Plumbing to Electrical Wiring:When possible a 150 mm (6 in) clearance should exist. When this is not possible or practical a 50 mm (2 in) minimum is acceptable provided that the elec
38、trical wiring or wire bundles are rigidly supported by conduit and/or closely spaced clamps or clips. When less than 50 mm (2 in) separation is necessary wires or wire bundles and electrical components must have additional insulation and be so supported that they cannot deflect closer than 13 mm (1/
39、2 in) from the oxygen components. As an additional protection the appropriate area of the oxygen line may be isolated by a retractable hose guard of non-corrosive material.Further, oxygen tubes and tube fittings shall not be closer than 50 mm (2 in) without insulation to any electrical components su
40、ch as relays that may be a fire source. Consider that if a fire did begin at the electrical component it may burn through the oxygen tube or fitting and the fire could be intensified by the addition of oxygen pressure and burning metal. A minor fire could become catastrophic.SAE INTERNATIONAL AIR825
41、/12A Page 6 of 14_ 4.7 Design Precautions:Reducing valve(s) should be installed as close as practicable to high pressure oxygen cylinder to minimize the amount of high pressure line installation.Oxygen cylinder(s) and lines shall be protected against high temperatures and shall not be installed in d
42、esignated fire zones. The support(s) of the oxygen cylinder shall be designed to withstand the flight, landing and crash loads.The installation of the oxygen cylinder, equipment and tubing shall be such that deformation of the fuselage in case of a landing with retracted nose landing gear or cargo s
43、hifting during crash landing will not cause rupture and escape of oxygen.Flexible connections specifically designed for oxygen system shall be provided between all points having relative or differential motion.4.8 Use of Dissimilar Materials:The use of dissimilar materials must be avoided to prevent
44、 corrosion due to electric potentials. If this cannot be avoided the surfaces must be protected appropriately. Application of varnish or paint inside of oxygen equipment and lines shall be excluded.4.9 Conduction of Electric Current:All elements must be designed for the same current. This must espec
45、ially be verified at the fittings.4.10 Reverse Electric Currents:Reverse currents on oxygen plumbing and equipment shall not occur.The system must be checked for absence of reverse currents with all adjacent systems switched on.4.11 Electrical Bonding:All conductive components of the system must be
46、protected against the effects of grounded electrostatic charge. The electrical resistance between the discharge mounting bases and the aircraft structure shall be for:- Stainless Steel Components: 100 m- Aluminum Alloy: 10 mElectrical and non-electrical components shall be individually bonded to the
47、 structure either directly or through the pipe system using bonding leads. The use of vibration isolators may mean that bonding leads are needed at various mounting locations. The system shall be bonded to the aircraft structure either through its attachments or by separate bonding leads.SAE INTERNATIONAL AIR825/12A Page 7 of 14_ 4.12 Tubing Markings:All plumbing (hose and tube assembly) shall have markings indicating “Breathing Oxygen,“ flow direction, and func
