1、BRITISH STANDARD BS ISO 14624-5:2006 Space systems Safety and compatibility of materials Part 5: Determination of reactivity of system/component materials with aerospace propellants ICS 49.025.01; 49.140 BS ISO 14624-5:2006 This British Standard was published under the authority of the Standards Pol
2、icy and Strategy Committee on 31 May 2006 BSI 2006 ISBN 0 580 48330 4 National foreword This British Standard reproduces verbatim ISO 14624-5:2006 and implements it as the UK national standard. The UK participation in its preparation was entrusted by Technical Committee ACE/68, Space systems and ope
3、rations, to Subcommittee ACE/68/-/1, Design engineering production, which has the responsibility to: aid enquirers to understand the text; present to the responsible international/European committee any enquiries on the interpretation, or proposals for change, and keep UK interests informed; monitor
4、 related international and European developments and promulgate them in the UK. A list of organizations represented on this subcommittee can be obtained on request to its secretary. Cross-references The British Standards which implement international publications referred to in this document may be
5、found in the BSI Catalogue under the section entitled “International 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 r
6、esponsible for its correct application. Compliance with a British Standard does not of itself confer immunity from legal obligations. Summary of pages This document comprises a front cover, an inside front cover, the ISO title page, pages ii to v, a blank page, pages 1 to 11 and a back cover. The BS
7、I copyright notice displayed in this document indicates when the document was last issued. Amendments issued since publication Amd. No. Date Comments Reference number ISO 14624-5:2006(E)INTERNATIONAL STANDARD ISO 14624-5 First edition 2006-04-15 Space systems Safety and compatibility of materials Pa
8、rt 5: Determination of reactivity of system/component materials with aerospace propellants Systmes spatiaux Scurit et compatibilit des matriaux Partie 5: Dtermination de la ractivit des matriaux des systmes/composants avec les ergols spatiaux BS ISO 14624-5:2006ii BS ISO 14624-5:2006iii Contents Pag
9、e Foreword iv Introduction v 1 Scope . 1 2 Normative references . 1 3 Terms and definitions. 1 4 Fluid transfer, storage, and flight systems 2 4.1 General. 2 4.2 Test criteria 2 4.3 Sample . 3 4.4 Test system . 3 4.5 Procedure 4 4.6 Precision 6 4.7 Good laboratory practices . 6 Annex A (informative)
10、 Example forms . 7 Bibliography . 11 BS ISO 14624-5:2006 iv Foreword 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 commit
11、tees. Each member 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 In
12、ternational Electrotechnical 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
13、 Standards adopted 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. Attention is drawn to the possibility that some of the elements of this document may be the
14、subject of patent rights. ISO shall not be held responsible for identifying any or all such patent rights. ISO 14624-5 was prepared by Technical Committee ISO/TC 20, Aircraft and space vehicles, Subcommittee SC 14, Space systems and operations. ISO 14624 consists of the following parts, under the ge
15、neral title Space systems Safety and compatibility of materials: Part 1: Determination of upward flammability of materials Part 2: Determination of flammability of electrical-wire insulation and accessory materials Part 3: Determination of offgassed products from materials and assembled articles Par
16、t 4: Determination of upward flammability of materials in pressurized gaseous oxygen or oxygen- enriched environments Part 5: Determination of reactivity of system/component materials with aerospace propellants Part 6: Determination of reactivity of processing materials with aerospace fluids Part 7:
17、 Determination of permeability and penetration of materials to aerospace fluids v Introduction This purpose of this part of ISO 14624 is to identify changes resulting from exposure of a material to an aerospace fluid that renders either the material or the fluid unsuitable for use. BS ISO 14624-5:20
18、06blank 1 Space systems Safety and compatibility of materials Part 5: Determination of reactivity of system/component materials with aerospace propellants 1 Scope This part of ISO 14624 specifies test equipment and techniques used to identify interactions resulting from exposure of a material to an
19、aerospace fluid. This part of ISO 14624 may be used to determine the reactivity of system and component materials with aerospace fluids. It is applicable for determining interactive reactions between propellants and materials used in the design, construction, and operation of propellant storage, tra
20、nsfer, and flight systems. While this procedure is an excellent quick screen test for long-term propellant compatibility, it is semi-qualitative, and (if exposures exceed 12 months) long-term tests need to be used to quantify degradation as a function of time under use conditions. 2 Normative refere
21、nces The following referenced documents are 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 4954:1993, Steels for cold heading and c
22、old extruding ISO 14951-3, Space systems Fluid characteristics Part 3: Nitrogen 3 Terms and definitions For the purposes of this document, the following terms and definitions apply. 3.1 degradation adverse physical or chemical change in a substance 3.2 immersion test test in which the fluid covers t
23、he entire sample for the duration of the test 3.3 propellants fluids, such as hydrazine and monomethylhydrazine, and oxidizers usually used for space projects 3.4 reaction chemical change in which a substance decomposes, combines with other substances, or interchanges constituents with other substan
24、ces BS ISO 14624-5:20062 4 Fluid transfer, storage, and flight systems 4.1 General 4.1.1 Procedure This procedure is applicable for determining interactive reactions between propellants and materials used in the design, construction, and operation of propellant storage, transfer, and flight systems.
25、 The sample is immersed in the test fluid for 48 h at the maximum system temperature or 71 C (160 F), whichever is higher. This accelerated test provides semi-qualitative information. Tests used to evaluate the long-term interaction of materials with reactive fluids shall be conducted for a period o
26、f time no less than that of the anticipated time of use. 4.1.2 Safety The proper safety equipment must be worn by the technician performing the test. A face shield, gloves, and a laboratory coat or apron shall be worn when handling the test fluids. The laboratory conducting the tests shall have a de
27、tailed emergency plan in the event of a runaway reaction. 4.2 Test criteria 4.2.1 Screening test Exposure of the material (screening test) to the fluid for 2 h at ambient temperature and pressure shall not visibly change either the material or the fluid. 4.2.2 Immersion test The sample immersed in t
28、he test fluid for 48 h at test temperature shall not cause a pressure rate increase that is 1,5 times more than the pressure rate increase that is caused by ISO 4954 stainless steel when exposed to the identical fluid and conditions. The standard test temperature for the hydrazine propellants (see I
29、SO 14951-6 and ISO 14951-7) is 71 C. This temperature shall be used when the intent of the test is ranking of materials or comparison to literature information. Other temperatures may be used to test materials for specific applications. For other fluids, the standard test temperature will depend upo
30、n the vapour pressure of that fluid; for example, the standard temperature for nitrogen tetroxide (see ISO 14951-5) is 21 C. For fluids that do not decompose into gaseous products at the test temperature (for example, nitrogen tetroxide), the pressure increase shall not be greater than the vapour pr
31、essure of the fluid after exposure to polytetrafluoroethylene (for nonmetals) or ISO 4954 stainless steel (for metals). 4.2.3 Post-test analysis After the sample has been exposed, decontaminated, and dried, no visible change in colour or texture of the material or test fluid shall be apparent. In ad
32、dition, the sample mass change shall not be greater than 2 %. The following also apply: the mass of impurities in the fluid after exposure to the material shall not be greater than twice the mass of impurities in the identical fluid after exposure to polytetrafluoroethylene (for nonmetals) or ISO 49
33、54 stainless steel (for metals); halide (F , Cl , Br ) concentrations in the fluid after exposure to the material shall not exceed the appropriate ISO specification for the fluid purity. BS ISO 14624-5:2006 3 4.3 Sample 4.3.1 Receiving inspection When received, the test material must be accompanied
34、by proper identification. The minimum information required is the manufacturer, trade name, composition, specification, generic name, and batch/lot number (if known). A visual inspection shall be performed and any anomalies shall be noted. A suitable material identification form is shown in A.1. 4.3
35、.2 Sample preparation The sample shall be tested in the intended use form (such as sheets or foams) and in the as-received thickness. Samples for the screening test shall weigh u 0,25 g. Samples for the immersion test shall have a surface area of 25 10 mm 2 . 4.3.3 Sample cleaning Samples shall be c
36、leaned and dried to the end-use specifications. Contamination on the surfaces of solid, nonporous samples shall be removed by washing with de-ionized water and mild detergent, rinsing with de- ionized water, and drying with filtered, gaseous nitrogen. Particulate on the surfaces of solid, porous sam
37、ples shall be removed with filtered, gaseous nitrogen meeting the requirements of ISO 14951-3. 4.3.4 Sample inspection The cleaned sample shall be inspected to ensure it is at the specified worst-case thickness. Flaws and any residual contamination shall be noted. If the flaws result from sample pre
38、paration at the test facility, new samples shall be prepared. Samples with flaws that inordinately increase the surface area to bulk mass ratios shall not be tested. Samples shall be weighed and individually identified. 4.4 Test system 4.4.1 Screening test The test system for the screening test shal
39、l consist of a glass beaker. 4.4.2 Immersion test The test system for the immersion test shall consist of one reference and one sample chamber and temperature- and pressure-measuring devices (see Figure 1). Differential pressure transducers may be used for fluids, such as hydrazine and monomethylhyd
40、razine, that decompose into gases at the test temperature. Absolute pressure transducers (on the sample and reference sides of the test system) may be used for those fluids that do not decompose into gases or undergo wide pressure fluctuations. Recommended analytical instruments for the post-test an
41、alyses include a differential scanning calorimeter, gas chromatography, gas chromatography/mass spectrograph, atomic absorption spectrophotometer, inductively coupled plasma optical spectrometer, inductively coupled plasma/mass spectrometer, ion chromatography, and high-performance liquid chromatogr
42、aphy. BS ISO 14624-5:20064 Key 1 solution valve 1 2 solution valve 2 3 test sample aVent to hood. bGaseous nitrogen source. cHeated volume. Figure 1 Immersion test system 4.5 Procedure 4.5.1 Before testing The test system shall be clean, and all measuring devices shall be in current calibration. The
43、 pretest procedure shall be as follows. a) Analyse the fluid to be used in testing for impurities. b) Verify the fluid meets the required use specifications before being exposed to the samples. c) Record all pertinent information for the test, such as sample identification and pretest information ab
44、out the sample and fluid. d) Clean and dry the test and reference samples. e) Photograph the samples. BS ISO 14624-5:2006 5 4.5.2 Test 4.5.2.1 Screening test The screening test shall be as follows. a) Place a 0,25 g test sample in the glass beaker. b) Apply 10 mm 3of fluid one drop at a time to the
45、test sample at ambient temperature and pressure. c) Wait 2 h, then examine the sample and fluid visually for obvious changes caused by the exposure. d) Complete a suitable screening test report form (see A.2). 4.5.2.2 Immersion test The immersion test shall be as follows. a) Place the test sample in
46、 the sample chamber and add sufficient liquid, approximately 25 ml, to completely cover the test sample for the duration of the test. The addition of the test fluid must be performed to rigorously exclude water and carbon dioxide in the case of the propellant hydrazines and water in the case of nitr
47、ogen tetroxide. Contamination of the test fluid by these chemicals may give false indications of reactivity. b) Seal the sample chamber to the sample side of the test apparatus. c) Add sufficient test fluid to the reference chamber to obtain the same ullage as in the sample chamber. d) Seal the refe
48、rence chamber to the reference side of the test apparatus. e) Activate the temperature- and pressure-monitoring devices. f) Heat both chambers at a rate of less than 2 C per minute until the test temperature, 71 C minimum, is reached. g) Continue the test for 48 h or until the pressure difference be
49、tween the sample and reference transducers (PT) has exceeded the vapour pressure of the fluid plus 140 kPa. h) Allow the temperature to lower to ambient. 4.5.3 Post-test analysis The post-test analysis shall be as follows. a) Perform a post-test analysis of the material and fluid to determine the extent of changes in the physical and chemical characteristics. The removal of the test fluid from the test system m
