1、BRITISH STANDARD BS ISO 14624-7:2006 Space systems Safety and compatibility of materials Part 7: Determination of permeability and penetration of materials to aerospace fluids ICS 49.025.01; 49.140 BS ISO 14624-7:2006 This British Standard was published under the authority of the Standards Policy an
2、d Strategy Committee on 31 May 2006 BSI 2006 ISBN 0 580 48332 0 National foreword This British Standard reproduces verbatim ISO 14624-7:2006 and implements it as the UK national standard. The UK participation in its preparation was entrusted by Technical Committee ACE/68, Space systems and operation
3、s, 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 relat
4、ed 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 found
5、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 respons
6、ible 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 9 and a back cover. The BSI copyr
7、ight notice displayed in this document indicates when the document was last issued. Amendments issued since publication Amd. No. Date Comments Reference number ISO 14624-7:2006(E)INTERNATIONAL STANDARD ISO 14624-7 FIrst edition 2006-04-15 Space systems Safety and compatibility of materials Part 7: D
8、etermination of permeability and penetration of materials to aerospace fluids Systmes spatiaux Scurit et compatibilit des matriaux Partie 7: Dtermination de la permabilit et de la pntration des matriaux aux fluides arospatiaux BS ISO 14624-7:2006ii BS ISO 14624-7:2006iii Contents Page Foreword iv In
9、troduction v 1 Scope . 1 2 Normative references . 1 3 Terms and definitions. 1 4 Safety precautions 2 4.1 Laboratory facilities 2 4.2 Protective clothing 2 5 Test procedure 2 5.1 Inspection of sample on receipt 2 5.2 Preparation of sample 2 5.3 Penetration test. 3 5.4 Permeation test . 4 Annex A (in
10、formative) Examples of forms . 7 Bibliography . 9 BS ISO 14624-7:2006 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 tec
11、hnical committees. 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 closel
12、y with the International 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
13、International 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. ISO 14624-7 was prepared by Technical Committee ISO/TC 20, Aircraft and space v
14、ehicles, Subcommittee SC 14, Space systems and operations. ISO 14624 consists of the following parts, under the general title Space systems Safety and compatibility of materials: Part 1: Determination of upward flammability of materials Part 2: Determination of flammability of electrical-wire insula
15、tion and accessory materials Part 3: Determination of offgassed products from materials and assembled articles Part 4: Determination of upward flammability of materials in pressurized gaseous oxygen or oxygen- enriched environments Part 5: Determination of reactivity of system/component materials wi
16、th aerospace propellants Part 6: Determination of reactivity of processing materials with aerospace fluids Part 7: Determination of permeability and penetration of materials to aerospace fluids v Introduction The purpose of this part of ISO 14624 is to provide procedures to determine the permeabilit
17、y rate and penetration resistance of materials exposed to aerospace fluids. BS ISO 14624-7:2006blank 1 Space systems Safety and compatibility of materials Part 7: Determination of permeability and penetration of materials to aerospace fluids 1 Scope This part of ISO 14624 specifies test equipment an
18、d techniques used to identify interactions resulting from exposure of a material to an aerospace fluid. This part of ISO 14624 can be used to determine the reactivity of materials with aerospace fluids. It provides a means to determine the effects of minor amounts of aerospace fluids, such as in a s
19、plash or spill, on materials used in ground support processing operations, and in the selection of personal safety equipment. 2 Normative references The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For un
20、dated references, the latest edition of the referenced document (including any amendments) applies. ISO 4954, Steels for cold heading and cold extruding ISO 6529, Protective clothing Protection against chemicals Determination of resistance of protective clothing materials to permeation by liquids an
21、d gases ISO 6530, Protective clothing Protection against liquid chemicals Test method for resistance of materials to penetration by liquids 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
22、 apply. 3.1 aerospace fluid fluid that is commonly used in the fabrication, development, processing of materials and production of aerospace and ground support equipment EXAMPLES Cleaning agents, lubricants and solvents. 3.2 degradation adverse physical or chemical change in a substance BS ISO 14624
23、-7:20062 3.3 reaction chemical change in which a substance decomposes, combines with other substances, or interchanges constituents with other substances 4 Safety precautions 4.1 Laboratory facilities Some aerospace fluids are considered to be toxic chemicals. These chemicals shall only be exposed t
24、o room atmosphere inside an approved laboratory hood. Separate, dedicated hoods shall be used for the oxidizers and fuels. 4.2 Protective clothing Personal protective clothing shall be worn by personnel when performing these tests. The minimum protection required is fluid-compatible gloves, laborato
25、ry apron and face shield or goggles. 5 Test procedure 5.1 Inspection of sample on receipt When received, the test material shall be accompanied by proper identification. The minimum information required is the manufacturer, trade name, composition, specification, generic name and batch/lot number (i
26、f known). A visual inspection shall be performed and any anomalies shall be noted. A suitable sample identification form is shown in Table A.1. 5.2 Preparation of sample 5.2.1 General The sample shall be tested in the intended use form (such as sheets or foams) and in the as-received thickness. 5.2.
27、2 Sample cleaning Samples shall be cleaned and dried to the end-use specifications. Contamination on the surfaces of solid, nonporous samples shall be removed by washing with deionized water and mild detergent, rinsing with deionized water, and drying with filtered, gaseous nitrogen. Particulates on
28、 the surfaces of solid, porous samples shall be removed with filtered, gaseous nitrogen meeting the requirements of ISO 14951-3. 5.2.3 Sample inspection The sample shall be inspected to ensure it is at the specified worst-case thickness. Flaws and any residual contamination shall be noted. If the fl
29、aws result from sample preparation 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. BS ISO 14624-7:2006 3 5.3 Penetration test 5.3.1 Gener
30、al This test is used to determine the possible liquid penetration of materials when exposed to aerospace fluids or other chemicals of interest. 5.3.2 Test procedure The test procedure shall be as follows. a) Place an appropriately sized sample of the test material (see Figure 1) over a beaker. b) Ad
31、d the test fluid, approximately 1 ml of the specified test fluid, to the centre of the sample, taking care not to expose the edges of the sample to the fluid, and start the timer. c) Allow the test fluid to stand on the sample for the specified exposure time. d) Add test fluid as required to maintai
32、n a liquid film on the test sample during the specified exposure time. e) Carefully observe for the first fallen droplet at the bottom of the beaker, stop the timer, and note the time of occurrence. f) For materials used for protective garments, observe for initial wetness underneath the test sample
33、 and note the time of occurrence. NOTE Atmospheric condensation could occasionally form underneath a sample during a test, giving a false indication of penetration. In such an event, verification can be made by applying a hypergol-compatible blotter that is known to discolour when in contact with a
34、particular aerospace fluid. g) Carefully blot the liquid from the sample at the end of the specified exposure time. h) Rinse the sample with running water for 60 s. i) Allow the test sample to air dry for 24 h prior to final evaluation. Dimensions in millimetres a) Penetration test specimen aRadius
35、as specified in ISO 6529 or ISO 6530. b) Permeability test specimen Figure 1 Test specimens BS ISO 14624-7:20064 5.3.3 Report The report shall consist of the following as a minimum (an example of a suitable form for reporting the results of this test is shown in Table A.2): a) name of the test mater
36、ial, supplier, and manufacturer; b) test temperature, pressure, duration, and sample thickness before and after the test; c) any penetration observed during the exposure and the elapsed time of occurrence; d) for materials used for protective garments, any wetness observed underneath the test sample
37、 during the exposure and the elapsed time of occurrence; e) any reactivity observed during the exposure, such as burning, smoking, bubbling, frothing, charring, solubility, swelling or fracture of the sample; f) any changes in the condition of the sample after the exposure, such as colour, flexibili
38、ty, rigidity, surface condition, transparency, pitting, hardness, tackiness, friability or powder formation. 5.4 Permeation test 5.4.1 General This test is used to determine the vapour or liquid permeation rate of a material when exposed to aerospace fluids or other chemicals of interest as specifie
39、d by the requester. Two kinds of permeability tests may be performed: conditioned and/or unconditioned. The conditioned test is performed on specimens that have been exposed to the test fluid prior to a permeability test in order to simulate used materials. The unconditioned test is performed on new
40、, unused specimens in the as-received condition. Unless otherwise specified, the duration of the permeability test shall be 120 min. 5.4.2 Configuration requirements The permeability tests shall be performed in accordance with ISO 6529 or ISO 6530, or other approved test methods as appropriate. Mate
41、rials used for enclosed, pressurized, protective garments shall always be tested with the pressure on the collection side of the test cell maintained between 10 mm and 20 mm of water above the pressure applied on the test fluid side of the cell. If conditioned test specimens are used, the conditione
42、d side shall be facing the test fluid side of the cell. 5.4.3 Preparation of conditioned test samples The preparation shall be as follows. a) Place the test specimen (Figure 1) on a flat stainless-steel or polytetrafluoroethylene base plate (see Figure 2). The side of the material that is normally e
43、xposed in service shall be in the up position. The stainless-steel base plate shall meet the requirements of ISO 4954. b) Apply a bead of fluid-compatible grease to a template (see Figure 2) around the opening (to prevent wicking under the template). c) Clamp the template (with the grease against th
44、e test specimen) and test specimen to the base plate. The test specimen shall be sandwiched between the template and the base plate. d) Place sufficient test fluid on the specimen to wet the entire surface. e) Allow the test fluid to remain in contact with the test specimen for 60 s. BS ISO 14624-7:
45、2006 5 f) Carefully remove the test fluid, rinse the test specimen with deionized water for 60 s, and disassemble the test fixture. g) Wipe the grease off the test specimen, taking care not to contaminate the propellant exposed area of the test specimen. h) Allow the test specimen to air dry for 24
46、h. i) Perform this process with the same sample using, in order, monomethylhydrazine, nitrogen tetroxide and hydrazine. j) Condition the test specimen a second time. Dimensions in millimetres a) Base plate b) Template NOTE Items are constructed from stainless steel or Teflon, to a size specified in
47、ISO 6529 or ISO 6530. Figure 2 Conditioning fixture for permeability test 5.4.4 Test procedure for oxidizer permeability The method specified in either ISO 6529 or ISO 6530 shall be used as appropriate. The test cell shall be compatible with the oxidizer. This test shall be conducted with the test c
48、ell oriented such that the test specimen is in contact with the gas phase only. The test procedure shall be as follows. a) Fill the assembled test cell approximately half full with liquid oxidizer. b) Allow the oxidizer vapours to vent freely for approximately 60 s, then seal the test cell. c) After
49、 120 min, open the seals and drain the oxidizer from the test cell. d) Disassemble the test cell. e) Decontaminate the test specimen by gently blotting any liquid from the sample and rinsing it with running water for 60 s. f) Allow the test sample to air dry for 24 h. BS ISO 14624-7:20066 5.4.5 Test procedure for aerospace fluid permeability The method specified in either ISO 6529 or ISO 6530, or another suitable test
