1、 Reference number ISO 23935:2006(E) ISO 2006INTERNATIONAL STANDARD ISO 23935 First edition 2006-06-15 Aircraft 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 embar
2、qus Tenue au feu dans les zones dsignes zone de feu ISO 23935:2006(E) PDF disclaimer This PDF file may contain embedded typefaces. In accordance with Adobes licensing policy, this file may be printed or viewed but shall not be edited unless the typefaces which are embedded are licensed to and instal
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7、35:2006(E) ISO 2006 All rights reserved iii 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 committees. Each membe
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11、atent rights. ISO shall not be held responsible for identifying 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. INTERNATIONAL STANDARD ISO 23935:2006(E) ISO 2006 All right
12、s reserved 1 Aircraft Environmental test procedures for airborne fluid system components Resistance to fire in 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 combust
13、ion. 1 Scope This International Standard specifies the requirements for tests which may be applied to all fluid 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 wit
14、hstanding fire outside designated fire zones, nor to flammability requirements, or to those conditions induced by 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, on
15、ly the edition cited applies. For undated references, the latest edition of the referenced document (including any 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
16、 this document, the following terms and definitions apply. 3.1 designated fire zone region of an aircraft, for example 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 comp
17、onent any part of a fluid system which is to convey and/or contain fluid in liquid or gaseous condition 3.3 fire resistant 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
18、 application of heat by a standard flame for 15 min ISO 23935:2006(E) 2 ISO 2006 All rights reserved4 Test equipment The test rig shall be in accordance 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
19、circuit. 5 Test requirements 5.1 Test procedure The following procedure applies to all fire tests. For general requirements concerning the mounting 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. Th
20、e 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 applies. 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 appl
21、ication 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 fluid 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
22、 component as specified in the relevant procurement speci- fication. ISO 23935:2006(E) ISO 2006 All rights reserved 3 5.1.1.4 Flow rate The flow rate shall be less than or equal to the minimum working flow under normal operating conditions, as specified in Table 2. Table 2 Flow rate Flow rate 10 % C
23、ode dm 3 /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 specification, expressed in millimetres. bd is the minimal internal diameter of the hose as specified in the relevant proc
24、urement 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 and 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 t
25、ested 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 enveloped by the test flame. 5.1.1.7 Test duration The test duration shall be in accordance with the grade designated f
26、or 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 5.1.2.1 Test fluid The test conditions of the test fluid shall be equivalent to the normal operating conditions of the
27、 working fluid. Test fluid codes are identical to those in 5.1.1.1. ISO 23935:2006(E) 4 ISO 2006 All rights reserved5.1.2.2 Fluid temperature The fluid temperature inside the component shall be greater than or equal to the maximum working temperature under normal operating conditions. When “no flow”
28、 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 The pressure shall be greater than or equal to the maximum working pressure under normal ope
29、rating 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 with the worst working vibration level (frequency and amplitude) un- der normal operating
30、 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 duration The test duration shall be in accordance with the grade designated for the compo
31、nent 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. 6 Designation Reference to this International Standard shall be made in one of two wa
32、ys: 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 Designation using standard codes ISO 23935:2006(E) ISO 2006 All rights reserved 5aOptional c
33、odification 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 temperature 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 ISO 23935:2006(E) ICS 49.080 Price based on 5 pages ISO 2006 All rights reserved
