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 theref
2、rom, 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 InternationalAll rights reserved. No part of this publi
3、cation 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: +1 724-776-4970 (out
4、side USA)Fax: 724-776-0790Email: CustomerServicesae.orgSAE WEB ADDRESS: http:/www.sae.orgSAE values your input. To provide feedbackon this Technical Report, please visithttp:/www.sae.org/technical/standards/AIR825/3AEROSPACEINFORMATION REPORTAIR825/3Issued 2010-08Reaffirmed 2015-08Gaseous Oxygen and
5、 Oxygen Equipment,IntroductoryRATIONALEAIR825/3 has been reaffirmed to comply with the SAE five-year review policy.TABLE OF CONTENTS 1. SCOPE 32. REFERENCES 32.1 Applicable Documents 32.1.1 SAE International Publications 32.2 Definitions . 33. OXYGEN . 43.1 Gaseous Oxygen 43.2 Chemical Oxygen 43.3 L
6、iquid Oxygen . 43.4 On Board Oxygen Generator Systems (Molecular Sieve) 43.5 Other On Board Generating Technologies . 44. OXYGEN SYSTEMS . 44.1 Fixed Oxygen Systems . 44.1.1 Supply . 54.1.1.1 High Pressure Cylinders . 54.1.1.2 Low Pressure Cylinders 54.1.1.3 Cylinder Filling . 54.1.1.3.1 On Board Ox
7、ygen Generation 54.1.2 Supply System Accessories and Components . 54.1.2.1 Cylinder Valves . 64.1.2.2 Safety Devices 64.1.2.3 Cylinder Pressure Gauges 64.1.2.4 Remote Pressure Gauges 64.1.2.5 Warning Devices . 64.1.2.6 In-Line Fuse 74.1.2.7 Check Valves for Crew . 74.1.2.8 High Pressure Lines 74.1.2
8、.9 High Pressure Fittings . 84.1.2.10 Low Pressure Lines 84.1.2.11 Low Pressure Fittings . 84.1.3 System Pressure Regulator 84.1.4 Dispensing Oxygen . 94.1.4.1 Flight Deck Crew Oxygen Dispensing Systems . 94.1.4.2 Passenger Oxygen Dispensing Systems 94.1.5 Fire Safety . 94.2 Rotor Burst Protection .
9、 104.3 Portable Oxygen Systems 104.3.1 Gaseous Portable Oxygen Unit 105. NOTES 10SAE INTERNATIONAL AIR825/3 2 OF 101. SCOPE This Aerospace Information Report provides a general discussion on gaseous breathing oxygen and oxygen equipment for use on commercial aircraft. Other types of oxygen systems a
10、re mentioned to assist in this discussion. For detailed information on systems other than gaseous, reference the appropriate section of AIR825. 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 publi
11、cations shall apply. The applicable issue of the other publications shall be the issue in effect on the date of the purchase 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, s
12、upersedes applicable laws and regulations unless a specific exemption has been obtained. 2.1.1 SAE International Publications Available from: SAE International, 400 Commonwealth Drive, Warrendale, PA 15096-0001, Tel: 877-606-7323 (inside USA and Canada) or 724-776-4970 (outside USA), www.sae.org. AI
13、R 825/4 Chemical Oxygen Systems AIR 825/5 Liquid Oxygen Systems AIR 825/6 On Board Oxygen Generating Systems (Molecular Sieve) AIR 825/8 Continuous Flow Oxygen Systems AIR 825/9 Demand Oxygen Systems AIR 825/12 Oxygen System Integration and Performance Precautions AIR 825/13 Guide for Evaluating Com
14、bustion Hazards in Aircraft Oxygen Systems AS1046B Minimum Standard for Portable Gaseous, Oxygen Equipment AS 1066B Minimum Standards for Valve, High Pressure Oxygen, Cylinder Shut Off, Manually Operated AS1225A Oxygen System Fill/Check Valve ARP1532 Aircraft Oxygen System Lines, Fabrication, Test a
15、nd Installation ARP4287 Automatic Presentation of Supplemental Oxygen Masks AS8010 Aviators Breathing Oxygen Purity Standard 2.2 Definitions Oxygen Cylinder: Pressure vessel to store breathing gas (oxygen) under pressure. Such equipment is available in various sizes and designed according to EIGA, I
16、CC or DOT specifications. Cylinder Valves: A device installed on the end of the pressure vessel to control or shutoff the flow of the gas. ICC: Interstate Commerce Commission. The ICC was an independent agency of the U.S. government that was established in 1887and one of the function of the agency w
17、as to regulate the manufacture and transportation of pressurized vessels. The ICCs safety functions were transferred to the Dept. of Transportation in 1966. SAE INTERNATIONAL AIR825/3 3 OF 10DOT: Department of Transportation. The DOT was established in 1966 and incorporated many of the functions of
18、the ICC including regulating the manufacture and transportation of pressurized vessels. EIGA: Provide information and recommendations to local, national and international authorities and organizations for their guidance in the preparation of laws, regulations and standards which are both practical a
19、nd effective 3. OXYGEN Current aircraft breathing oxygen systems may utilize either a gaseous, chemical, liquid or on-board generated oxygen supply. These systems indicate the method of storage, since when the system delivers the oxygen to the user the oxygen, is in its gaseous state. 3.1 Gaseous Ox
20、ygen Gaseous oxygen systems store oxygen in its gaseous state in cylinders. Currently the oxygen storage cylinders may be high pressure 12.75 to 20.7 Mpa (1850 to 3000 Psig) or low pressure 2.76 to 3.45 Mpa (400 to 500 Psig). A regulator or shutoff device is installed on the cylinder as a means to s
21、tart and stop the flow of oxygen. Additionally a regulator will regulate the oxygen pressure from the cylinder down to 0.68 Mpa (100 Psi) or less as a means to minimize the use of high-pressure oxygen lines. 3.2 Chemical Oxygen A chemical oxygen generator produces gaseous oxygen by means of a chemic
22、al reaction involving the decomposition of a chemical. For information on chemical oxygen generators, reference AIR825/4. 3.3 Liquid Oxygen Liquid oxygen systems are designed to store oxygen in its liquid state and convert it to its gaseous state when required for use. This type of oxygen is current
23、ly use only for military applications and not for commercial use due to logistics reasons. For information on liquid oxygen, reference AIR825/5. 3.4 On Board Oxygen Generator Systems (Molecular Sieve) On Board Oxygen Generator System (Molecular Sieve) utilize the ability of molecular sieve materials
24、 by using Rapid Pressure Swing Adsorption Process to separate and concentrate oxygen in the product gas from the surrounding air and to provide this as supplement oxygen for breathing gas supply for the crew and in some cases the passengers. For information on OBOGS/M, reference AIR825/6. 3.5 Other
25、On Board Generating Technologies On Board Oxygen Generator System (Electrolysis) utilizes the ability of electric power to split water molecules into oxygen and hydrogen gases which provides the breathing oxygen for the crew and in some cases the passengers. For information on OBOGS/E, reference AIR
26、825/7. 4. OXYGEN SYSTEMS Oxygen equipment to fulfill mans physiological needs in aircraft falls into two general categories: fixed and portable. Fixed equipment is generally provided in those aircraft in which oxygen is frequently required or many passengers are involved. The installation of a quant
27、ity of portable oxygen units on aircraft, which has fixed oxygen, depends on the FAA/EASA requirements for the crew and passengers and whether there is a requirement to move around the aircraft cabin. Portable oxygen equipment may also be required for first aid and / or therapeutic purposes can be p
28、rovided in aircraft where the use of oxygen is infrequent. For information on minimum standards for portable gaseous oxygen equipment reference: AS1046. 4.1 Fixed Oxygen Systems A fixed oxygen system typically will consist of a supply, means to regulate the pressure of that supply, and a means to di
29、spense the oxygen. SAE INTERNATIONAL AIR825/3 4 OF 104.1.1 Supply The supply of oxygen (i.e. how it is stored on the aircraft) will depend on the type of oxygen being used. In a gaseous oxygen system, the oxygen is stored in a pressure vessel/cylinder, where typical maximum cylinder pressure is 12.7
30、5 to 20.7 Mpa (1850 to 3000 Psig). The cylinders in common usage are made from steel and composite materials. The cylinder assembly must have a means to start and stop the flow of oxygen. Additionally, if applicable, the cylinder assembly should have a means to regulate the flow of oxygen from the c
31、ylinder. It is recommended that this be accomplished with a cylinder mounted slow opening valve or cylinder mounted regulator assembly to avoid adiabatic compression of the downstream components. 4.1.1.1 High Pressure Cylinders The cylinders store gas at 12.41 to 14.48 MPa (1800 to 3000 Psig) and ar
32、e available in a variety of shapes and sizes. Steel Cylinders: Steel cylinders of regular shape with hemispherical ends are commonly in use. Refer to AIR825/14 for illustrations of the weights and dimensions of the cylinders used by commercial carriers. DOT Specification 3AA covers the design and ma
33、nufacture of regulator non-shatterable cylinders. DOT Specification 3HT covers “lightweight” cylinders of the same basic sizes, which show a saving in weight of 15 to 30 percent of the weight of the equivalent 3AA type. Composite Cylinders: Composite Oxygen Cylinders consists of an aluminum alloy se
34、amless inner liner that is wrapped with kevlar or carbon fiber and sealed in epoxy matrix. These cylinders provide approximately 50 to 60% weight saving over the other conventional steel cylinders and are covered by DOTFRP-1 for Kelvar wrapped cylinders and DOT-CFFC for carbon fiber wrapped cylinder
35、s. 4.1.1.2 Low Pressure Cylinders These cylinders are intended to store gas at 2.76 to 3.45 Mpa (400 to 500 Psig). They are used mainly in military applications where the smaller energy release on bursting is considered a useful characteristic. For commercial application and use, DOT approved cylind
36、ers are available. 4.1.1.3 Cylinder Filling Typically, the cylinders are filled or “charged” from other oxygen cylinders with higher storage pressures. The common practice is to perform the filling process while the cylinder remains installed onboard the aircraft or the cylinder can be removed from
37、the aircraft and filled at a remote location. Suitable procedures must be followed to ensure safety during the filling process. For aircraft filling or topping off, filler valves are often used that meet AS1225. For information on filler valves, reference AS1225. For information on Transfilling and
38、Maintenance of Oxygen Cylinders, reference AIR1059. 4.1.1.3.1 On Board Oxygen Generation Oxygen generated on board the aircraft can be used to supply oxygen directly to dispensing equipment, to fill or to top off the oxygen storage cylinders. Several methods of generating the oxygen on board are che
39、mical generation, molecular sieve, electrolysis, or ceramic membrane. Systems utilizing these sources of oxygen may have different controls, sensors, or components than discussed herein. In addition, consideration of any differences in oxygen quality shall be taken into account in the systems design
40、. For information on chemical generation, molecular sieve, electrolysis, or ceramic membrane, reference AIR 825/4, 825/6, or 825/7 respectively. 4.1.2 Supply System Accessories and Components Various items and components are required to provide a complete and workable system. The components referred
41、 to herein may be optional in some designs, not applicable in some designs, or mandatory in others. Added components not mentioned may be needed depending on a particular system requirements. SAE INTERNATIONAL AIR825/3 5 OF 104.1.2.1 Cylinder Valves Varieties of cylinder valves are available with th
42、reads on the body for screwing into the cylinder neck. Typically, the outlet thread on the side of the cylinder valve is a .903-14 Compressed Gas Association No. 540 and an adapter is needed to convert to a standard tube fitting. State of the art cylinder valves are available with “slow-opening” fea
43、ture. This feature decreased the heat build-up due to adiabatic compression and thus protects downstream components from reaching their ignition temperatures. For more information on minimum standards applicable to manually operated high-pressure oxygen cylinder shutoff valves reference AS1066. 4.1.
44、2.2 Safety Devices DOT regulations require that all high-pressure cylinders be provided with a safety device to guard against bursting due to excessive pressure. This generally takes the form of a rupture disc incorporated in the cylinder valve. DOT-3HT / -FRP-1 / -CFFC cylinders (12.75 Mpa (1850 Ps
45、ig) or below) must be equipped with a frangible disc safety relief device, without fusible backing. The rated bursting pressure of the disc shall not exceed 90% of the minimum required test pressure of the cylinders with which the device is used. A threaded outlet is provided on some designs of cyli
46、nder valves so that oxygen discharge may be piped overboard if desired. Stainless steel lines are typically utilized for this overboard piping. A commonly used method to indicate a discharge from the cylinder is by utilizing a overboard discharge port. The overboard discharge port is made of a housi
47、ng with hole through the middle and a frangible disc installed over the hole. When a cylinder discharge occurs, the frangible disc is discharged from the housing and indicates to the flight crew during preflight checks or maintenance personnel during inspections that a discharge has occurred. The di
48、scharge port is commonly installed on the aircraft skin in locations easily accessible to the flight crew or maintenance personnel. 4.1.2.3 Cylinder Pressure Gauges These are desirable when cylinders are to be recharged away from the aircraft and are incorporated as part of the cylinder valve in most designs. They are also used in some cases when the cylinder is accessible to indicate the available volume. 4.1.2.4 Remote Pressure Gauges Remote pressure gauges or monitors are sometimes required to indicate the quantity of the oxygen supply. They may indicate directly or they may tr
