SAE AIR 1392A-1998 Oxygen System Maintenance Guide《氧气系统维护指南》.pdf

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

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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/AIR1392A AEROSPACE INFORMATION REPORT AIR1392 REV. A Issued 1977-10 Revised 1998-

5、12 Reaffirmed 2013-12 Superseding AIR1392 Oxygen System Maintenance Guide RATIONALE AIR1392A has been reaffirmed to comply with the SAE five-year review policy. FOREWORDChanges in this revision are format/editorial only.1. SCOPE:This document is intended to give general instructions and directions f

6、or personnel performing maintenance and modification work on Oxygen Systems.2. REFERENCES:2.1 FAA/DOT Specifications and Documents Applicable to Aircraft Oxygen Systems:Advisory Circular 43.13-2 Oxygen System Installation2.2 SAE Documents Applicable to Aircraft Oxygen Systems:2.2.1 Aerospace Standar

7、ds (AS):AS861 Minimum General Standards for Oxygen Systems2.2.2 Aerospace Information Reports (AIR):AIR822 Oxygen Systems for General Aviation AircraftAIR825A Oxygen Equipment for AircraftAIR1059 Transfilling and Maintenance of Oxygen CylindersAIR1176 Oxygen System and Component Cleaning and Packagi

8、ngAIR1223 Installation of Liquid Oxygen Systems in Civil Aircraft3. SAFETY:The use of oxygen and oxygen systems involves a certain degree of hazard. With the proper design, installation, and maintenance, this hazard can be reduced to an acceptable level.Oxygen in gaseous or liquid form is chemically

9、 stable and nonflammable. However, combustible materials ignite more rapidly and the intensity of a fire increases tremendously in an oxygen-rich atmosphere.A major factor in oxygen systems is cleanliness. This is most important in fabrication, installation, and maintenance of equipment. From the in

10、stallation standpoint, the hazards of contamination should be minimized, if not completely eliminated, by choosing proper locations for the equipment and by adequate precautions and shielding where choice of location is limited.4. INSTALLATION:Care should be taken in the installation of the oxygen s

11、ystem. Protect all lines and fittings from any unnecessary abuse or scratches during installation. Low pressure aluminum alloy plumbing lines are likely to become damaged; therefore, installation and location should be so accomplished as to prevent oxygen equipment or plumbing from subjection to vib

12、ration, abrasion, or damage during other maintenance operations. All oxygen system lines, after installation, should be carefully inspected for damage and leakage. Leak testing can be accomplished by introducing the oxygen pressure into the system and examining connections by the use of a leak detec

13、tion solution specifically approved for oxygen service. Before any oxygen system component is removed or any connection is loosened, oxygen system pressure should first be dissipated.5. EQUIPMENT HANDLING:All oxygen equipment should be handled with care to avoid association with hydrocarbons such as

14、 fuels and lubricants which are ever present where aircraft are serviced and/or maintained. Because most oxygen components are of an intricate nature and all require cleanliness for proper operation, they should be kept in their original containers or be provided with a proper protective covering un

15、til ready for installation in the aircraft. This is also necessary when any of the items from an aircraft are removed for service and/or overhaul. Keep protective caps in position on equipment as long as possible and replace as soon as possible. Do not tamper with safety device or mar identifying ma

16、rkings or symbols and/or nameplates.SAE INTERNATIONAL AIR1392A Page 2 of 6_6. MODIFICATION INSTALLATION:When oxygen equipment is modified and/or replaced with new or different equipment, the following should be taken into consideration prior to making the actual installation:The oxygen equipment, tu

17、bing, and fittings shall be located as remotely as practicable from fuel, oil, hydraulic fluid, storage batteries, exhaust sacks and manifolds, electrical radios, and insulating materials. Insofar as practical, oxygen lines should not be grouped with lines carrying flammable fluids. Where necessary,

18、 deflector plates should be used to keep flammable fluids away from oxygen lines and equipment. Components of any oxygen system should not be installed where they will be subjected to temperatures in excess of that specified in the individual component specifications, and no part of the system shall

19、 be installed in an area which will be subjected to a temperature of 180 F (82 C) or greater.7. CLEARANCE REQUIREMENTS:Wherever possible oxygen lines, fittings, and equipment shall be installed above and at least 6 inches (152.4 mm) away from fuel, oil, and hydraulic systems to avoid contamination.

20、Deflector plates should be used where necessary to keep hydraulic fluid away from oxygen lines, fittings, and equipment. Open ends of cleaned and died tubing should be plugged with impermeable caps at all times except during attachment or detachment. There should be at least 2 inches (50.8 mm) of cl

21、earance between the oxygen system and flexible moving parts of the aircraft. There should be at least half-inch clearance between the oxygen system and rigid parts of the aircraft. The oxygen system tubings, fitting and equipment should be separated by at least 6 inches (152.4 mm) from all electrica

22、l wiring, heat conduits and heat emitting equipment in the aircraft. Insulation shall be provided on the hot ducts, conduits, or equipment to prevent overheating of the oxygen system.8. TORQUENING OF JOINTS:Tightening of flared tube and pipe connections shall be accomplished in accordance with the b

23、est commercial practice. Torque wrenches shall be used, and the torque applied shall be within the limits specified in Tables 1 and 2.SAE INTERNATIONAL AIR1392A Page 3 of 6_9. OXYGEN SYSTEM AND COMPONENT CLEANING:9.1 Oxygen system components, including supply plumbing, can most effectively be cleane

24、d when not installed in the system. Components containing plastic or elastomeric parts are subject to damage when exposed to some cleaning agents and they result in odors which are difficult to remove satisfactorily. Contaminants, such as oil, dust, metal chips, etc., cannot be easily removed by gas

25、 purging or liquid flushing within the installed system. Such contaminants can eventually become trapped in some narrow orifices causing either partial or complete failure of the system. In addition, if the contaminant is of the combustible type, a fire hazard is possible. Such contaminants can only

26、 be removed by complete disassembly of the affected component followed by proper cleaning procedures and controlled handling of the clean component until reinstalled into the using system.9.2 Cleaning materials and processes used shall be compatible with the pieces being cleaned. Solutions and solve

27、nts used for cleaning and gases used for drying shall be of sufficient purity to prevent accumulation of undesirable residue after drying.TABLE 1 - Torque Requirements for Flared Tube ConnectionsTubing O.D.Inch (mm)MinimumTorqueInch-Pounds (Nm)MaximumTorqueInch-Pounds (Nm)5/16 (8) 100 (135.6) 125 (1

28、69.5)3/8 (10) 200 (271.2) 250 (339.0)1/2 (13) 300 (406.8) 400 (542.3)TABLE 2 - Torque Requirements for Pipe Connections1Nominal PipeSizeInch (mm)MinimumTorqueInch-Pounds (Nm)MaximumTorqueInch-Pounds (Nm)1/8 (3) 40 (54.2) 150 (203.4)1/4 (6) 60 (81.4) 200 (271.2)3/8 (10) 100 (135.6) 400 (542.3)1Torque

29、 to specified minimum value and check for leakage. Ifadditional torque is required to stop leakage, torque may beapplied up to specified maximum value.SAE INTERNATIONAL AIR1392A Page 4 of 6_9.3 Cleaning agents must be completely removed from all equipment. The cleaned equipment shall be carefully ex

30、amined for any trace of cleaning agents. After solvent cleaning, check for solvent residues using a Halogen Detector. After cleaning with a water-soluble cleaning agent, visually inspect the equipment for complete moisture removal. If components that have been previously cleaned are not to be used i

31、mmediately they should be wrapped and/or sealed in a polyethylene bag and to the exterior of the bag should be placed the following: “Cleaned for Oxygen Use” and date.10. TRANSFILLING OF OXYGEN CYLINDERS:10.1 Filling or recharging of oxygen cylinders may be accomplished by removal of the cylinder fr

32、om the aircraft or by the use of central point filler valves normally accessible from outside the aircraft. Either method is acceptable. The central point filling minimizes a major difficulty in cylinder removal which is maintaining the mandatory cleanliness of the system. In cylinder removal, one o

33、r more lines must be disconnected, and the cylinder and/or systems are subjected to the possibility of contamination. Before any oxygen cylinder filling the following precautions must be taken: Each cylinder should be inspected for conformance to latest DOT regulations. Oxygen cylinders that conform

34、 to the DOT regulations are marked to indicate specification number and the “service pressure” for which the cylinders are designed. This marking is normally located immediately below the neck ring and consists of a combination of numbers and letters. For example, the designation DOT 3A1800 (12.4 MP

35、a) indicates that the cylinder was fabricated and tested in accordance with DOT specification 3A for a service pressure of 1800 psig (12.4 MPa). Additional marks normally located beneath this marking include an identifying number of the cylinder owners and a series number. In addition, the date of o

36、riginal manufacture and a symbol identifying the manufacturer are also located on the shoulder of the cylinder. In accordance with specific DOT regulations, certain cylinders must be retested before recharging as follows: Specification 3A and 3AA cylinders must be retested every 5 years; Specificati

37、on 3HT cylinders must be retested every 3 years. In the case of 3HT cylinders, after 4380 refills or 15 years (whichever comes first), the cylinder must be scrapped. All cylinders that do not conform to the above requirements should not be filled. Nonconforming cylinders may be forwarded to a cylind

38、er manufacturer or DOT/FAA authorized reconditioning facility.10.2 If non-standard ambient temperatures should prevail at the time of filling, refer to Table 3 to determine the proper filling pressure for oxygen cylinders. Table 3 should be used as a guide and has been found to be sufficiently accur

39、ate.SAE INTERNATIONAL AIR1392A Page 5 of 6_PREPARED BY SAE COMMITTEE A-10, AIRCRAFT OXYGEN EQUIPMENTTABLE 3At TemperatureF (C)Fill to Working Pressurex Figure BelowAt TemperatureF (C)Fill to Working Pressurex Figure Below110 (43.3) 1.10 70 (21.1) 1.000105 (40.6) 1.0875 65 (18.3) 0.9875100 (37.8) 1.075 60 (15.6) 0.97595 (35.0) 1.0625 55 (12.8) 0.962590 (32.2) 1.05 50 (10.0) 0.9585 (29.4) 1.0375 45 (7.2) 0.937580 (26.7) 1.025 40 (4.4) 0.92575 (23.9) 1.0125SAE INTERNATIONAL AIR1392A Page 6 of 6_