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 reaffirmed, revised, or cancelled. SAE invites your written comments and suggestions. Copyright 2010 SAE International All rights reserved. No part of this publication ma
3、y 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 (outside US
4、A) Fax: 724-776-0790 Email: CustomerServicesae.org SAE WEB ADDRESS: http:/www.sae.orgSAE values your input. To provide feedback on this Technical Report, please visit http:/www.sae.org/technical/standards/AS611EAEROSPACESTANDARDAS611 REV. E Issued 1963-03 Reaffirmed 2004-07 Revised 2010-04Supersedin
5、g AS611D (R) Hose Assembly and Tubing, Polytetrafluoroethylene, Cleaning Methods for RATIONALERevision E change implements a modification to Class 0 cleaning, para 3.1.2 and 3.4.1.a. This Revision also updates and reformats the Specification. 1. SCOPE 1.1 This SAE Aerospace Standard (AS) describes c
6、leaning methods for four cleanliness levels of polytetrafluoroethylene hose assemblies and rigid tube assemblies for use in aerospace systems. 1.2 Classification Class 0 Cleaning, Hydraulic minimum thickness of 2 mil. The bag, tubing, or film shall be at least as clean as the internal surfaces of th
7、e hose assembly onto which they are installed. c. Tape Material shall be per A-A-1689 or MIL-T-22085 and is used to secure the intimate barrier bag, tubing, or film to the hose assembly. The tape may also be used to close the open ends of bags, tubing, or film when used for an outer barrier.Copyrigh
8、t SAE International Provided by IHS under license with SAENot for ResaleNo reproduction or networking permitted without license from IHS-,-,-SAE AS611E Page 4 of 11d. Bags, Tubing, and Films - Outer Barrier Outer barrier bags, tubing, and films are used as a packaging technique and are not in contac
9、t with the cleaned internal surfaces of the hose assembly. Materials may be anti-static PTFE, FEP (fluorinated ethylene-propylene), nylon, or polyethylene with a 4 mil minimum thickness (these outer barrier materials are suitable for use as an intimate barrier for Class 0 and Class I only - due to r
10、elatively low criticality of the cleaning levels). 3.2 Purging Gases Purging, drying and pressure testing of Class I, II and III hose assemblies after cleaning and prior to shipment or use of Class I, II and III hose assemblies shall be done with nitrogen in accordance with MIL-PRF-27401 or BB-N-411
11、 Type I, Class I, Grade A. Clean, dry air may also be used if its purity conforms to the requirements in specified in Table 1. TABLE 1 - PURITY REQUIREMENTS - AIR TotalHydrocarbons(PPM max) by Weightas Carbon ParticlesOver 100 m Max Grams of Water Vapor per Liter of Gas at 70 F (21.1 C) and 760 mm
12、Hg 3 0 0.0000211Equivalent Dew Point: at 760 mm Hg -63.5 F (-53 C).3.3 Handling After Cleaning 3.3.1 All hose assemblies shall be sealed immediately or as specified after the level of cleanliness is achieved and testing, inspection and drying are completed. See 3.5 for preservation requirements. 3.3
13、2 All handling after cleaning and sealing shall be planned to maintain the clean condition of the hose assembly during the packaging, shipment and storage. Handling and preservation after cleaning shall be done in areas away from high manufacturing contamination; for example: areas of high solvent
14、use, grinding, blasting or other abrasion processes. 3.3.3 Class II hose assemblies shall be processed after cleaning in a dust control area as described in 3.3.4 or in a normal manufacturing area if hose assembly parts are sealed immediately after drying. 3.3.4 Class III hose assemblies shall be pr
15、ocessed after cleaning in a dust control area: The area shall be enclosed and kept clean from dust, dirt, oil and such contaminants. Smoking or eating shall not be allowed within the area. A slight positive air pressure shall be maintained with respect to adjacent, lesser controlled areas, the input
16、 air shall be filtered.Floor, walls and ceiling, benches and tables shall be painted or have non-dusting, non-flaking and easily cleaned surfaces.Parts and equipment not related to the work function shall be kept from the work area. 3.4 Cleaning Procedures 3.4.1 Class 0 Cleaning Hose assemblies for
17、use in hydraulic and other general purpose applications (that require minimum cleaning) shall be cleaned in the following manner: Copyright SAE International Provided by IHS under license with SAENot for ResaleNo reproduction or networking permitted without license from IHS-,-,-SAE AS611E Page 5 of
18、11a. Immerse or flush the hose assemblies, using a suitable cleaning solution in accordance with 3.1.2, 3.1.3 or 3.1.4. b. If using 3.1.4 fluids other than organic solvents, rinse inside surfaces thoroughly with 3.1.2 water. c. Drain hose assemblies and blow dry with shop air. Gas in accordance with
19、 3.2 may be used instead of or in addition to shop air. d. See Section 4 and Table 4 for Quality Assurance Provisions. Accepted hose assemblies shall be preserved for shipment per 3.5. 3.4.2 Class I Cleaning Hose assemblies for use in hydraulic and/or other systems where a moderate degree of cleanli
20、ness is required shall be cleaned in the following manner: a. Prior to assembly, all fittings shall be cleaned with a 3.1.3 or 3.1.4 fluid. If using 3.1.4 fluids other than organic solvents, follow with a thorough water rinse per 3.1.2. Dry with purging gas in accordance with 3.2 or by heating for 6
21、0 min at 250 to 275 F (121 to 135 C) in a suitably designed oven. b. Immerse or flush hose assemblies in a cleaning fluid in accordance with 3.1.3 or 3.1.4 and brush bore of fittings and first inch of hose with a nylon or similar synthetic bristle brush with a diameter at least 0.06 in (1.59 mm) lar
22、ger than the fitting bore. For hose sizes -08 and smaller, the brush size may be reduced but must be greater than hose bore. The brush should have a corrosion resistant core. On hose assemblies incorporating tight elbow end fittings, the brushing operation may be eliminated. c. Subject hose assembly
23、 to a flood of cleaning fluid in accordance with 3.1.3 or 3.1.4 through the bore of the hose assembly for a minimum of 1 min. d. If using 3.1.4 fluids other than organic solvents, rinse inside surfaces thoroughly with 3.1.2 water. e. Dry the hose assembly with purging gas in accordance with 3.2 both
24、 internally and externally (the external drying need not coincide with that for internal surface) for a minimum of 1 min or by heating for 45 min (minimum) at 250 to 275 F (121 to 135 C) in a suitably designed oven. f. See Section 4 and Table 4 for Quality Assurance Provisions. Accepted hose assembl
25、ies shall be preserved for shipment per 3.5. 3.4.3 Class II Cleaning Hose assemblies for use in cleanliness controlled systems or systems not compatible with oil, such as oxygen systems, shall be cleaned as follows: a. Prior to assembly, all fittings shall be cleaned with a 3.1.3 or 3.1.4 (except do
26、 not use organic solvents in the processing of Class II components) fluid. If using 3.1.4 fluids, follow with a thorough water rinse per 3.1.2. Dry with purging gas in accordance with 3.2 or by heating for 45 min (minimum) at 250 to 275 F (121 to 135 C) in an oven free from all vapors except water a
27、nd that of the solution used in cleaning. b. Handling practices shall be consistent with requirements under 3.3.3 or 3.3.4. Parts and assemblies shall be stored and handled during manufacture in clean, grease free and oil free containers. c. Proof testing shall be done with clean water in accordance
28、 with 3.1.2. Any gas pressure testing shall be done with gases in accordance with 3.2 or equivalent. d. Immerse hose assemblies in a cleaning fluid in accordance with 3.1.3 or 3.1.4 (except do not use organic solvents in the processing of Class II assemblies) and brush bore of fittings and first inc
29、h of hose with a nylon or similar synthetic bristle brush with a diameter at least 0.06 in (1.59 mm) larger than the fitting bore. Copyright SAE International Provided by IHS under license with SAENot for ResaleNo reproduction or networking permitted without license from IHS-,-,-SAE AS611E Page 6 of
30、 11For hose sizes -08 and smaller, the brush size may be reduced but must be greater than hose bore. The brush should have a corrosion resistant core. On hose assemblies incorporating tight elbow end fittings, the brushing operation may be eliminated. e. Subject the hose assembly to a flood of clean
31、ing fluid in accordance with 3.1.3 or 3.1.4 (except do not use organic solvents in the processing of Class II assemblies) through the bore of the hose assembly for a minimum of 3 min. The minimum flow rate shall be in accordance with Table 2: TABLE 2 - MINIMUM FLOW RATES Size Flowgpm Size Flowgpm-03
32、 0.5 -10 6.0 -04 1.0 -12 9.5 -05 1.5 -16 19.0 -06 2.5 -20 30.0 -08 4.0 -24 40.0 f. If using 3.1.4 fluids, rinse inside surfaces thoroughly with 3.1.2 water. g. Dry the hose assembly with purging gas in accordance with 3.2 both internally and externally (the external drying need not coincide with the
33、 internal) for a minimum of 3 min or by heating for 45 min (minimum) at 250 to 275 F (121 to 135 C) in a suitably designed oven. h. See Section 4 and Table 4 for Quality Assurance Provisions. Accepted hose assemblies shall be preserved for shipment per 3.5. 3.4.4 Class III Cleaning Hose assemblies f
34、or use in contaminant free or highly reactive fluid systems shall be cleaned in the following manner: a. Follow steps a. through f. of 3.4.3. b. Passivate assemblies internally with the following solution heated to 120 to 140 F (49 to 60 C) for 20 to 30 min: (1) Nitric Acid (Reagent Grade 69-71 by w
35、eight): 25 to 35% by volume (2) Sodium Dichromate: 1.5 to 2.5% by weight (3) Water in accordance with 3.1.2: Remainder NOTE: Sodium dichromate may be omitted from the solution if only 300 Series stainless steel metal components are to be passivated. c. Rinse assemblies in 170 to 190 F (77 to 88 C) w
36、ater in accordance with 3.1.2 for a minimum of 5 min; parts should be agitated during rinsing. d. Dry hose assemblies with drying gas in accordance with 3.2 or by heating for 45 min (minimum) at 250 to 275 F (121 to 135 C) in a suitably designed oven. Copyright SAE International Provided by IHS unde
37、r license with SAENot for ResaleNo reproduction or networking permitted without license from IHS-,-,-SAE AS611E Page 7 of 11The next three steps (e, f, and g) to take place in a dust control area. e. Flush assemblies internally with clean, filtered, or distilled O-E-760 Ethyl Alcohol, MIL-F-5566 Ant
38、i-Icing Fluid, ASTM D 4376 Perchloroethylene, ASTM D 4080 Trichloroethylene, ASTM D 4126 1,1,1 Trichloroethane, TT-I-735 Isopropyl Alcohol, Hydrofluroether (3M HFE-7100, other grades should be tested for compatibility), MSFC 237 solvent or equivalent.f. Dry hose assemblies with drying gas in accorda
39、nce with 3.2 or by heating for 45 min (minimum) at 250 to 275 F (121 to 135 C) in a suitably designed oven. g. See Section 4 and Table 4 for Quality Assurance Provisions. Accepted hose assemblies shall be preserved for shipment per 3.5. 3.5 Preservation The objective of the preservation process is t
40、o maintain the cleanliness level of the hose assembly during subsequent packaging, shipment, handling, and storage. In the case of Class II and III cleaned assemblies, identification of the precision clean status of the hose assemblies is also provided. Unit packaging requirements for shipment is a
41、separate issue which is not addressed in this specification. 3.5.1 Preservation for Class 0 and Class I Assemblies a. Each hose assembly shall be preserved with threaded caps and closures (3.1.5(a) or bags (3.1.5(b) or 3.1.5(d). If threaded caps or closures are used, they should be installed hand ti
42、ght. If bags are used, the bag should be heat sealed or taped (3.1.5(c) shut. Preservation materials should be clean and dry. 3.5.2 Preservation for Class II and Class III Assemblies a. Each hose assembly shall be preserved with an intimate barrier consisting of a threaded cap or closure (3.1.5(a) o
43、r a nylon barrier (3.1.5(b) secured with tape (3.1.5(c). The closure shall be at least as clean as the internal surfaces of the hose assembly onto which they are installed. If threaded caps and closures are used, they should be installed hand tight. If nylon is used, it should be constructed from fi
44、lm or tubing into a bag shape with one end left open. The closed sides may be sealed via tape or heat sealing technique. Slide the open end of the bag over the end fitting and seal/secure in place with tape (3.1.5(c). The tape is applied at the interface between the nylon bag and the collar or socke
45、t. b. Each hose assembly shall be preserved with an outer barrier consisting of a bag (3.1.5(d) with two compartments separated by a heat sealed divider. The hose assembly with intimate barriers is placed inside one compartment and partially sealed with tape (3.1.5(c) or with heat (continuous 0.06 i
46、n (1.59 mm) seam, minimum). Purge the interior of the partially sealed compartment with nitrogen (3.2). Remove as much gas as practical from the compartment and complete the seal. Install and seal the appropriate identification tag per Table 3 in the remaining separate compartment of the outer bag.
47、TABLE 3 - IDENTIFICATION ClassIdentificationTag Color IdentificationTag Legend II Green Not to be opened except by authorized personnel - This assembly is specially cleaned in accordance with AS611, Class II. III Tan Not to be opened except by authorized personnel - This assembly specially cleaned i
48、n accordance with AS611, Class III. Copyright SAE International Provided by IHS under license with SAENot for ResaleNo reproduction or networking permitted without license from IHS-,-,-SAE AS611E Page 8 of 114. QUALITY ASSURANCE PROVISIONS 4.1 Frequency of Tests Each lot of hose assemblies shall be subjected to the conformance tests shown in 4.2 as specified in 4.3. A lot consists of all hose assemblies processed at one time, not to exceed 100 pieces. If the tested assembly fails to pass the conformance test requirements, the entire lot of assemblies shall be recl
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