1、BRITISH STANDARD AEROSPACE SERIES BS ISO 14952-6:2003 Space systems Surface cleanliness of fluid systems Part 6: Precision-cleaning processes ICS 49.080; 49.140 BS ISO 14952-6:2003 This British Standard was published under the authority of the Standards Policy and Strategy Committee on 20 February 2
2、004 BSI 20 February 2004 ISBN 0 580 43467 2 National foreword This British Standard reproduces verbatim ISO 14952-6:2003 and implements it as the UK national standard. The UK participation in its preparation was entrusted to Technical Committee ACE/68, Space systems and operations, which has the res
3、ponsibility to: A list of organizations represented on this committee can be obtained on request to its secretary. Cross-references The British Standards which implement international publications referred to in this document may be found in the BSI Catalogue under the section entitled “Internationa
4、l Standards Correspondence Index”, or by using the “Search” facility of the BSI Electronic Catalogue or of British Standards Online. This publication does not purport to include all the necessary provisions of a contract. Users are responsible for its correct application. Compliance with a British S
5、tandard does not of itself confer immunity from legal obligations. aid enquirers to understand the text; present to the responsible international/European committee any enquiries on the interpretation, or proposals for change, and keep the UK interests informed; monitor related international and Eur
6、opean developments and promulgate them in the UK. Summary of pages This document comprises a front cover, an inside front cover, the ISO title page, pages ii to iv, pages 1 to 7 and a back cover. The BSI copyright notice displayed in this document indicates when the document was last issued. Amendme
7、nts issued since publication Amd. No. Date Comments Reference number ISO 14952-6:2003(E) OSI 3002INTERNATIONAL STANDARD ISO 14952-6 First edition 2003-11-15 Space systems Surface cleanliness of fluid systems Part 6: Precision-cleaning processes Systmes spatiaux Propret des surfaces en contact avec d
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13、41 O6:(3002E) I SO 3002 All irhgts seredevr iiiForeword ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO member bodies). The work of preparing International Standards is normally carried out through ISO technical committees. Each me
14、mber body interested in a subject for which a technical committee has been established has the right to be represented on that committee. International organizations, governmental and non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the International E
15、lectrotechnical Commission (IEC) on all matters of electrotechnical standardization. International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2. The main task of technical committees is to prepare International Standards. Draft International Standards ad
16、opted by the technical committees are circulated to the member bodies for voting. Publication as an International Standard requires approval by at least 75 % of the member bodies casting a vote. ISO 14952-6 was prepared by Technical Committee ISO/TC 20, Aircraft and space vehicles, Subcommittee SC 1
17、4, Space systems and operations. ISO 14952 consists of the following parts, under the general title Space systems Surface cleanliness of fluid systems: Part 1: Vocabulary Part 2: Cleanliness levels Part 3: Analytical procedures for the determination of nonvolatile residues and particulate contaminat
18、ion Part 4: Rough-cleaning processes Part 5: Drying processes Part 6: Precision-cleaning processes BSISO149526:2003IS-25941 O6:(3002E) iv I SO 3002 All irhgts seredevrIntroduction This part of ISO 14952 defines precision-cleaning processes for fluid equipment and components used in space fluid syste
19、ms. The purpose of this part of ISO 14952 is to establish procedures and processes for use in the cleaning, analysis and verification of launch vehicles, spacecraft and ground support equipment. BSISO149526:2003INTENRATIONAL TSANDADR IS-25941 O6:(3002E)I SO 3002 All irhgts seredevr 1Space systems Su
20、rface cleanliness of fluid systems Part 6: Precision-cleaning processes 1 Scope This part of ISO 14952 specifies precision-cleaning processes for parts, components and systems used in flight-critical fluid applications. It can be used on equipment for ground support equipment, launch vehicles and sp
21、acecraft. This part of ISO 14952 identifies precision-cleaning processes and procedures that can be used on parts and components used in fluid systems and is applicable equally to ground support equipment, launch vehicles and spacecraft. 2 Normative references The following referenced documents are
22、indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. ISO 14951-3:1999, Space systems Fluid characteristics Part 3: Nitrogen ISO 14951-10:1999
23、, Space systems Fluid characteristics Part 10: Water ISO 14952-1:2003, Space systems Surface cleanliness of fluid systems Part 1: Vocabulary ISO 14952-3:2003, Space systems Surface cleanliness of fluid systems Part 3: Analytical procedures for the determination of nonvolatile residues and particulat
24、e contamination ISO 14952-5:2003, Space systems Surface cleanliness of fluid systems Part 5: Drying processes 3 Terms and definitions For the purposes of this document, the terms and definitions given in ISO 14952-1 apply. 4 Precision-cleaning requirements 4.1 General All parts, components, assembli
25、es, subsystems, systems or related equipment for use in ground support equipment, launch vehicles and spacecraft requiring cleaning shall be cleaned to the specified cleanliness level and inspected in accordance with this part of ISO 14952. Subsystems and systems may require disassembly to permit cl
26、eaning. Any part or component that might be damaged during cleaning shall be protected or removed before cleaning and cleaned as a separate item. Cleaning or disassembly operations on BSISO149526:2003IS-25941 O6:(3002E) 2 I SO 3002 All irhgts seredevrprecision components shall be performed only by c
27、ompetent personnel who have been trained and certified to perform these functions. The designs for systems and system components should, where practical, include the capability to remove all valves and components from the system for precision cleaning. 4.2 Environmental, health and safety considerat
28、ions This part of ISO 14952 allows the use of materials, processes, and equipment that may be hazardous, toxic and/or detrimental to the environment. This part of ISO 14952 does not purport to address all of the environmental, health or safety problems associated with precision-cleaning processes. I
29、t is the responsibility of the cleaning organization to determine and establish the appropriate environmental, health and safety practices that are in compliance with applicable regulations. a) Hazardous materials It is the responsibility of the cleaning organization to store all hazardous materials
30、 and inform the local emergency planning organization as to the quantity on hand and the storage location. Records shall be maintained by this organization as to the mass of hazardous material used and what happened to the material consumed in the product, released to the environment (spilled, air e
31、mission, land discharge, water discharge, underground injection), used for energy onsite, used for energy offsite, recycled offsite, recycled onsite, treated offsite or treated onsite. b) Waste minimization (recycling) It is the responsibility of the cleaning organization to implement waste reductio
32、n practices. Materials, especially test fluids, shall be recycled where applicable. 4.3 Precision cleaning All critical surfaces of system hardware shall be precleaned to remove dirt, grit, scale, corrosion, grease, oil and other foreign matter prior to any final precision-cleaning process. Metallic
33、 items shall be surface treated (cleaned, passivated and/or coated), as applicable, to prevent latent corrosion and contamination. Assembled items that do not lend themselves to this type of treatment shall be treated prior to assembly. Surface-treated areas degraded during subsequent fabrication an
34、d assembly shall be reprocessed, as required, to restore the original surface finish. Critical surfaces of system hardware that have been precleaned shall be visually clean prior to proceeding to any precision-cleaning operation. Scale-free discoloration due to welding or passivation shall be permit
35、ted. All critical hardware surfaces shall be precision cleaned to meet the requirements specified by the customer. Precision-cleaning operations shall be performed in an environment compatible with the component cleanliness requirements to preclude adverse effects on the functional performance. Exem
36、ptions may be requested for hardware which, due to size or other considerations, cannot meet this requirement. Precision cleaned articles shall be packaged immediately after verification and drying operations, or suitably protected prior to leaving the controlled environment. Solvents identified in
37、ISO 14952-3:2003, Table 1, as having low threshold limit values are not suitable for precision-cleaning processes conducted in enclosed environments, such as cleanrooms, due to their toxicity unless the facility is especially designed for their use. 4.4 Cleaning process approval Cleaning processes s
38、hall be left to the discretion of the cleaning organization; however, the process shall not be detrimental to the hardware being cleaned. Process approval shall be obtained from the customer prior to cleaning and handling. To obtain approval, the cleaning organization shall submit to the customer th
39、e following information: a) customer-specified cleanliness levels or proposed cleanliness levels, including analysis and rationale for the selected cleanliness levels; BSISO149526:2003IS-25941 O6:(3002E) I SO 3002 All irhgts seredevr 3b) description of items to be cleaned, including identification o
40、f materials; c) processing materials, to include as applicable, trade names, specifications, chemical and physical properties, and compatibility information as specified; d) processing equipment and cleaning procedures to be used; e) quality assurance provisions to be utilized; this shall include in
41、-process control procedures to prevent contamination, latent corrosion, or other degradation of surfaces and open systems or vessels; f) controlled environment levels to be maintained for cleaning and handling; g) preservation methods and materials; h) verification methods; see ISO 14952-3 for recom
42、mended verification procedures. 4.5 Materials The selection of materials used in processing shall be left to the discretion of the customer. However, the fluids shall be compatible with the items being cleaned. The following compatibility issues, as applicable, shall be considered and evaluated in t
43、he selection of processing materials: a) corrosion; b) stress corrosion cracking; c) embrittlement; d) leaching; e) masking of crack-like indications; f) residue; g) crazing (nonmetallics); h) reversion (nonmetallics); i) hydrolysis (nonmetallics)/water absorption; j) chemical activity. 4.6 Final ri
44、nsing solutions The final rinsing solution shall meet or exceed the cleanliness requirements for which they are intended. They shall also meet or exceed the following specific requirements. a) There shall be no particles greater than 175 m in any dimension and no more than 5 particles per millilitre
45、 between 100 m and 175 m per 500 ml. Particle corrections by subtracting the test solvent particles from the final particle count are not allowed. b) Nonvolatile residues shall not be greater than 10 mg per 500 ml. c) If water is used as the final rinse fluid, it shall meet the requirements of ISO 1
46、4951-10. d) The final rinsing solution shall be compatible with the fluid in the system being cleaned. BSISO149526:2003IS-25941 O6:(3002E) 4 I SO 3002 All irhgts seredevr4.7 Verification Precision-cleaned parts, components, systems and vessels shall be visually inspected and verified to meet the req
47、uired cleanliness in accordance with ISO 14952-3. Alternative verification procedures and/or corresponding cleanliness levels may be used only upon demonstration of equivalence and upon written approval by the customer. Verification shall be performed in an environment that is compatible with the en
48、vironment in which the cleaning was performed. 4.8 Packaging and protection 4.8.1 Approved coverings All critical surfaces or openings to critical surfaces shall be protected from contamination by sealing the surfaces or openings with approved coverings, and securing with tape or other approved meth
49、ods. Protected components shall be placed in clean bags, fabricated from packaging materials listed in ISO 14952-3:2003, Table 2, which have been cleaned internally and verified in accordance with ISO 14952-3:2003, 4.6. The interior of the bags and parts shall be purged with dry nitrogen meeting the requirements of ISO 14951-3, Type A. The bags shall be completely sealed to ensure the storage package is ine
