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/AIR4071AAEROSPACEINFORMATION REPORTAIR4071 REV. AIssued 1997-10Revised 2010-11Reaffirmed 2015
5、-08Superseding AIR4071Lubricants for Oxygen UseRATIONALEAIR4071A has been reaffirmed to comply with the SAE five-year review policy.1. SCOPE 1.1 Scope This SAE Aerospace Information Report (AIR) describes two classes of lubricants which, when properly applied, can be used in oxygen systems and compo
6、nents. 1.2 Product Classification Lubricants covered by this document are classified as follows: Class I Fluids and greases Class II Solids and dry films 1.3 Field of Application Molecular oxygen is an aggressive oxidizer, which will support and highly intensify combustion, which is why contact with
7、 conventional lubricants must be avoided. Only special sliding agents, tested under standardized conditions / materials and approved by certified Agencies, can safely handle their jobs in valves, fittings or systems that carry oxygen. The major requirement established is that lubricants must be prim
8、arily non-reactive, in all expected use conditions, to gaseous oxygen (GOX) and if applied to liquid oxygen (LOX). The emphasis on oxygen compatibility confines the choice of the components making up the formulation to non-reactive fluids, thickeners, powders and binders. These are typified by the f
9、ully fluorinated fluids - polyperfluoroalkylethers and polytetrafluoroethylene (PTFE), fluorinated ethylenepropylene (FEP) and by saturated hydrogen-free chlorofluorocarbons. 1.3.1 In selecting lubricants for oxygen systems, not only oxygen compatibility has to be considered but also their toxicity
10、property. A toxic or just skin irritating chemical, even if it is oxygen compatible, should not be used in oxygen systems. 1.3.2 Oxygen compatible lubricants are safer in oxygen systems only in the sense that the energy required to initiate a reaction is higher than that of conventional materials. U
11、nder appropriate conditions, all such materials are combustible in oxygen. 1.3.3 Prior to application of any lubricant, all components which come in contact with oxygen must be cleaned for oxygen service and thoroughly dried. 1.3.4 Fluids and greases will not function as lubricants at LOX temperatur
12、es -183 C (-297 F). Only solid or dry film lubricants can be used at these temperatures. To ensure maximum safety, contact the application engineers of the manufacturer. 1.3.5 Fluoro and chloro-organic compounds are capable of reacting with aluminum and magnesium, even in the absence of oxygen, when
13、 the metals are subjected to conditions of high shear or galling, as is the case with pipe threads. 1.3.6 Bonded solid lubricants do not provide corrosion resistance. The metal substrate must be protected or be a corrosion-resistant material prior to the application of the solid film. 1.3.7 Before u
14、se, check the product information leaflet, the data sheet and the materials safety data sheet to check the compatibility between the lubricant and the metal piping and any possible surrounding fluids. 1.3.8 If the lubricant should be used in connecting fittings/hose couplings (pipes, valves etc.), i
15、nform about the sealing effects. Read the data sheet and decide whether the lubricant meets your requirements. 1.3.9 If the lubricant should be used in connecting fittings in contact with other sealing materials (NBR, EPDM,FPM or PTFE), inform about the compatibility with those materials. 2. REFEREN
16、CES 2.1 SAE 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. ARP1176 Oxygen System and Component Cleaning and Packaging 2.2 ASTM Publications Available from ASTM Int
17、ernational, 100 Barr Harbor Drive, P.O. Box C700, West Conshohocken, PA 19428-2959, Tel: 610-832-9585, www.astm.org. ASTM G 72 Standard Test Method for Autogenous Ignition Temperature of Liquids and Solids in a High Pressure Oxygen-Enriched Environment 2.3 U.S. Government Publications Available from
18、 Document Automation and Production Services (DAPS), Building 4D, 700 Robbins Avenue, Philadelphia, PA 19111-5094, Tel: 215-697-6257, http:/assist.daps.dla.mil/quicksearch/ MIL-PRF-27617 Grease, Aircraft and Instrument, Fuel and Oxidizer Resistant MIL-PRF-81329 Lubricant, Solid Film, Extreme Environ
19、ment, NATO Code Number S-1737, Metric SAE AMS-M-7866 Molybdenum Disulfide Technical, Lubrication Guide A-A-58092 Tape, Anti-Seize, Polytetrafluoroethylene NAEG Misc. 92-0354 Compatibility of Materials with Oxygen NATO AEP-15C Lubricants for use in Oxygen Systems with Oxygen Rich Environments NATO ST
20、ANAG No. 3976 SAE INTERNATIONAL AIR4071A 2 OF 52.4 Other Publications Solid Lubrication Technology - Mahlon E. Cambell Midwest Research Institute, Kansas City, Missouri Du Pont Technical Bulletin G-6 Krytox Fluorinated Greases Du Pont Technical Bulletin L-6 Krytox 143 Fluorinated Oils Burman-Castrol
21、, Inc. Technical Bulletin Perfluorinated Greases Klber Lubrication, Technical Information, CRC Handbook of Lubrication and Tribology, E. Richard Booser, 1994 3. TECHNICAL REQUIREMENTS 3.1 Selection of Lubricants Lubricants, when needed, must be carefully selected for safe operation of equipment in
22、oxygen enriched environments. Lubricants should be selected through qualification tests. The qualification tests should be more severe than the conditions expected in actual use. Use only lubricants which have been qualified and batch/lot tested for oxygen service and use them sparingly. NOTE: The l
23、imits of temperature, pressure and pressure rise rate for their intended application must be specified and observed. The use of Class I lubricants (fluids and greases) that see direct oxygen service at pressures in excess of 500 psig (= 35 bar) is not recommended. Age controlled lubricants must not
24、be used after their shelf life has expired. Check the manufacturers certification, like ISO 9000ff, ISO 14001, ISO 21469 or OHSAS 18001. These types of quality-certificate stand for steady good products. 3.2 Description of Lubricants 3.2.1 Fluids and Greases 3.2.1.1 Specification MIL-PRF-27617 cover
25、s five types of grease. Separation of types is based primarily on the operating temperature of each. The definition of types is as follows: Type I -54 to 149 C ( -65 to 300 F) Type II -40 to 204 C ( -40 to 400 F) Type III -34 to 204 C ( -30 to 400 F) Type IV -73 to 204 C (-100 to 400 F) Type V -73 t
26、o 232 C (-100 to 450 F) Manufacturers designations for the various types are as noted in Military Qualified Products List, QPL-27617. NOTE: Check the latest issue of the above document to ensure current listing of qualified suppliers. 3.2.1.1.1 Krytox (E.I. du Pont Co.) 240 series fluorinated grease
27、s are straight greases without additives. They are insoluble in all common solvents including aliphatic hydrocarbons, aromatic hydrocarbons, alcohols, ketones, chlorinated hydrocarbons and water. One solvent which will gradually cause disintegration of the grease structure is trichlorotrifluoroethan
28、e. In general, Krytox 240 greases are not dissolved by highly chlorinated solvents but show some solubility in highly fluorinated liquids. These greases are suggested for use as lubricants for “O“ rings, valves and other fittings used in gasous oxygen systems. SAE INTERNATIONAL AIR4071A 3 OF 53.2.1.
29、1.2 Fomblin Y-VAC-3 (Montedison, USA, Inc.) is a perfluorinated polyether fluid, chemically similar to Krytox. This grease meets the type III requirement of MIL-PRF 27617. 3.2.1.1.3 Tribolube (Aerospace Lubricants, Inc.) is a perfluorinated ether base fluid meeting MIL-PRF-27617 requirements for Typ
30、e I, II, and Type III greases. They can be used at temperatures ranging from -42.7 to 204.4 C (-45 to 400 F). 3.2.1.1.4 Braycote (Burmah-Castrol Inc.) perfluorinated polyether greases are based upon perfluoroalkylether base oils and blended with tetrafluoroethylene thickeners. 3.2.1.1.5 Fluoroether
31、(William F. Nye, Inc.) Fluoroether greases are based on fluorinated oils gelled with fluorocarbon polymers. 3.2.1.1.6 CHRISTO-LUBE (Lubrication Technology Inc.) MCG 111 is a fluorinated polyether grease meeting MIL-PRF-27617 requirements for type I, II, and type III. 3.2.1.1.7 Krytox (E.I. du Pont C
32、o.) 143 oils are perfluorinated alkyl polyethers. Depolyermerization of the oil starts at about 288 C (550 F) when certain metal oxides are present, and the decomposition products are highly toxic. The oils are of a low order of toxicity at room temperature and are not significantly irritating to th
33、e skin or eyes. 3.2.1.2 Other Lubricants than mentioned in MIL Spec 3.2.1.2.1 Oxigenoex FF250 (Klber Lubrication), fluorinated polyether oil, PTFE, silicate. The oil is of a low order of toxicity and is not significantly irritating to the skin or eyes. 3.2.1.2.2 Oxigenoex FF450 (Klber Lubrication),
34、fluorinated polyether oil 3.2.1.2.3 Oxigenoex S4 (Klber Lubrication), methyle silicone oil, PTFE, silicate. The oil is of a low order of toxicity and is not significantly irritating to the skin or eyes. 3.2.1.2.4 Barrierta L55/3 OX (Klber Lubrication), PFPE, PTFE 3.2.1.2.5 Gleitmo 595 (Fuchs Lubrite
35、ch GmbH), white paste for high pressure and LOX, perfluorinated alkyl-polyether 3.2.2 Solids and Dry Films 3.2.2.1 A solid lubricant can be defined as a material that provides lubrication to two relatively moving surfaces under dry conditions. The most generally used solid lubricants are graphite, m
36、olybdenum disulfide, and polytetrafluoroethylene. MIL-L-81329 covers one grade of a solid film lubricant for use at temperatures ranging from -185 to 400 C (-301 to 752 F). 3.2.2.2 Molylube N: Molylube N is an inorganic, molybdenum disulfide, dry film lubricant. It is a LOX insensitive coating. All
37、surfaces should be thoroughly degreased before appling the coating which can be air-dried or baked. This lubricant meets all the requirements of MIL-M-7866. 3.2.2.3 Molylube Spray: Molylube spray contains molybdenum disulfide powder meeting the specification of MIL-M-7866. 3.2.2.4 Molybdenum Disulfi
38、de: It has been found that molybdenum disulfide oxidizes to molybdenum trioxide, which acts as an abrasive at 150 C (302 F) in oxygen and 398.9 C (750 F) in air. This oxide reduces the ability of the solid lubricant to protect the moving surfaces. SAE INTERNATIONAL AIR4071A 4 OF 5Although molybdenum
39、 disulfide is an inorganic compound, it is not inert in oxygen-enriched enviroments. Its auto ignition temperature (AIT) is about 260 C (525 F) in oxygen (ASTM G 72) which is low as compared with lubricants with AITs over 427 C (826 F). The above characteristics should be considered when utilizing m
40、olybdenum disulfide in oxygen enriched enviroments when the associated temperatures are encountered. 3.2.2.5 Teflon (E.I. du Pont Co.) Polytetrafluoroethylene, Teflon or PTFE is probably the most LOX compatible of all the organic material and is used extensively in oxygen systems. Generally the more
41、 halogenated (particularly with fluorine) a hydrocarbon is, the more compatible it is with oxygen. Teflon tape per MIL-T-27730 is used as an antiseize and sealant for pipe threads in oxygen systems. 4. NOTES 4.1 A change bar (|) located in the left margin is for the convenience of the user in locati
42、ng areas where technical revisions, not editorial changes, have been made to the previous issue of this document. An (R) symbol to the left of the document title indicates a complete revision of the document, including technical revisions. Change bars and (R) are not used in original publications, nor in documents that contain editorial changes only. PREPARED BY SAE COMMITTEE A-10, AIRCRAFT OXYGEN SAE INTERNATIONAL AIR4071A 5 OF 5
