1、BRITISH STANDARDBS ISO 23935:2006Aircraft Environmental test procedures for airborne fluid system components Resistance to fire in designated fire zonesICS 49.080g49g50g3g38g50g51g60g44g49g42g3g58g44g55g43g50g56g55g3g37g54g44g3g51g40g53g48g44g54g54g44g50g49g3g40g59g38g40g51g55g3g36g54g3g51g40g53g48g
2、44g55g55g40g39g3g37g60g3g38g50g51g60g53g44g42g43g55g3g47g36g58BS ISO 23935:2006This British Standard was published under the authority of the Standards Policy and Strategy Committee on 30 June 2008 BSI 2008ISBN 978 0 580 54464 4National forewordThis British Standard is the UK implementation of ISO 2
3、3935:2006. The UK participation in its preparation was entrusted to Technical Committee ACE/69, Aerospace hydraulic systems, fluids and components.A list of organizations represented on this committee can be obtained on request to its secretary.This publication does not purport to include all the ne
4、cessary provisions of a contract. Users are responsible for its correct application.Compliance with a British Standard cannot confer immunity from legal obligations.Amendments/corrigenda issued since publicationDate CommentsReference numberISO 23935:2006(E)INTERNATIONAL STANDARD ISO23935First editio
5、n2006-06-15Aircraft Environmental test procedures for airborne fluid system components Resistance to fire in designated fire zones Aronefs Mthodes dessai en environnement des lments de systmes de fluides embarqus Tenue au feu dans les zones dsignes zone de feu BS ISO 23935:2006ii iiiForeword ISO (th
6、e 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 member body interested in a subject for which a technical committ
7、ee 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 Inter-national Electrotechnical Commission (IEC) on all matters of electrotech
8、nical 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 adopted by the technical committees are circulated to the member
9、 bodies for voting. Publication as an Interna-tional 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 subject of patent rights. ISO shall not be held responsible for identifyin
10、g any or all such patent rights. ISO 23935 was prepared by Technical Committee ISO/TC 20, Aircraft and space vehicles, Subcommittee SC 10, Aerospace fluid systems and components. BS ISO 23935:2006blank1Aircraft Environmental test procedures for airborne fluid system components Resistance to fire in
11、designated fire zones CAUTION Precautions shall be taken to safeguard the health of personnel conducting tests against the risk of fire, inhalation of smoke and/or toxic products of combustion. 1 Scope This International Standard specifies the requirements for tests which may be applied to all fluid
12、 system com-ponents located in zones designated as “fire zones” and built to satisfy the minimum level specified for with-standing fire. This International Standard does not relate to withstanding fire outside designated fire zones, nor to flammability requirements, or to those conditions induced by
13、 the flame coming from the combustion chamber. 2 Normative references The following referenced documents are indispensable for the application of this document. For dated refer-ences, only the edition cited applies. For undated references, the latest edition of the referenced document (including any
14、 amendments) applies. ISO 2685:1998, Aircraft Environmental test procedure for airborne equipment Resistance to fire in designated fire zones. 3 Terms and definitions For the purposes of this document, the following terms and definitions apply. 3.1 designated fire zone region of an aircraft, for exa
15、mple compartments containing main engines and auxiliary power units, desig-nated as such by the aircraft designer in accordance with the requirements of the approving authority 3.2 component any part of a fluid system which is to convey and/or contain fluid in liquid or gaseous condition 3.3 fire re
16、sistant grade designating components capable of withstanding the application of heat by a standard flame for 5 min 3.4 fireproof grade designating components capable of withstanding the application of heat by a standard flame for 15 min BS ISO 23935:20062 4 Test equipment The test rig shall be in ac
17、cordance with ISO 2685:1998. The test rig shall withstand the test conditions and simulate, as much as possible, the operating conditions of the real fluid circuit. 5 Test requirements 5.1 Test procedure The following procedure applies to all fire tests. For general requirements concerning the mount
18、ing of the specimen, and the choice and calibration of the burner, ISO 2685:1998 applies. The test conditions may vary during the fire exposure duration. The regulation of all these test conditions shall be stipulated in the test report. 5.1.1 Standard test conditions 5.1.1.1 Test fluid Table 1 appl
19、ies. Table 1 Test fluid codes Code Test fluid A Fuel or high-temperature resisting oil B Air or nitrogen 5.1.1.2 Fluid temperature 5.1.1.2.1 For liquid application The fluid temperature inside the component shall be between 93 C and 110 C (200 F and 230 F). 5.1.1.2.2 For gaseous application The flui
20、d temperature inside of the component shall be between 18 C and 22 C (64,5 F and 71,5 F). 5.1.1.3 Pressure The pressure shall be the nominal pressure of the component as specified in the relevant procurement speci-fication. BS ISO 23935:200635.1.1.4 Flow rate The flow rate shall be less than or equa
21、l to the minimum working flow under normal operating conditions, as specified in Table 2. Table 2 Flow rate Flow rate 10 % Code dm3/min (l/min)a(US gallon/min)bA No flow No flow B 0,006 d 21 d 2C 0,03 d 25 d 2ad is the minimal internal diameter of the hose as specified in the relevant procurement sp
22、ecification, expressed in millimetres. bd is the minimal internal diameter of the hose as specified in the relevant procurement specification, expressed in inches. 5.1.1.5 Vibration level Components shall be vibrated along or perpendicular to the axis of the component at a frequency between 30 Hz an
23、d 60 Hz and with a minimum amplitude of 1,6 mm (0,063 in) in front of the flame. 5.1.1.6 Flame location The hose to be tested shall be not less than 600 mm (23,6 in) long. Hoses shall be mounted horizontally and shall include one 90 bend. One end fitting and at least 120 mm (4,7 in) of hose shall be
24、 enveloped by the test flame. 5.1.1.7 Test duration The test duration shall be in accordance with the grade designated for the component to resist fire, i.e. fire re-sistant or fireproof (see 3.3 and 3.4). See Table 3. Table 3 Test duration Code Duration min 05 5 15 15 5.1.2 Specific test conditions
25、 5.1.2.1 Test fluid The test conditions of the test fluid shall be equivalent to the normal operating conditions of the working fluid. Test fluid codes are identical to those in 5.1.1.1. BS ISO 23935:20064 5.1.2.2 Fluid temperature The fluid temperature inside the component shall be greater than or
26、equal to the maximum working temperature under normal operating conditions. When “no flow” or low flow rate is applied, these temperatures are only given at the beginning of the fire test. The fluid temperature shall not be regulated better than under normal operating conditions. 5.1.2.3 Pressure Th
27、e pressure shall be greater than or equal to the maximum working pressure under normal operating condi-tions. 5.1.2.4 Flow rate The flow rate shall be less than or equal to the minimum working flow under normal operating conditions. 5.1.2.5 Vibration level The vibration level shall be in accordance
28、with the worst working vibration level (frequency and amplitude) un-der normal operating conditions. 5.1.2.6 Flame location The flame shall be located in front of the most critical exposed area of the component in accordance with the working position under normal operating conditions. 5.1.2.7 Test d
29、uration The test duration shall be in accordance with the grade designated for the component to resist fire, i.e. fire re-sistant or fireproof (see 3.3 and 3.4). 5.2 Test acceptance conditions As conditions of acceptance, the system components shall show no evidence of leakage over the test duration
30、. 6 Designation Reference to this International Standard shall be made in one of two ways: either by using standard codes (when standard test conditions are applied) or by using the real test condition values, as specified in Figures 1 and 2, respectively. EXAMPLE ISO FFFFF CLASS A15B Figure 1 Desig
31、nation using standard codes BS ISO 23935:20065aOptional codification when different test conditions are used during a second part of the test: EXAMPLE ISO FFFFF A15-0060-210-025-10-0000-210-10 When test conditions are the same for the total duration, the designation shall stop just after the first t
32、emperature value: EXAMPLE ISO FFFFF A15-0060-210-025 When a test condition is unchanged during the second part of the test, it shall not be omitted in the designation. Figure 2 Designation using real test condition values BS ISO 23935:2006BS ISO 23935:2006BSI Group Headquarters389 Chiswick High Road
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