1、BRITISH STANDARD AEROSPACE SERIES CONFIRMED OCTOBER 1983 BS 3G. 100-2.3.4:1972 Specification for General requirements for equipment in aircraft Part 2: All equipment Section 3: Environmental conditions Subsection 3.4: Differential pressure requirements UDC 629.7.05/06:620.162.4BS3G. 100-2.3.4:1972 T
2、his British Standard, having been approved by the AerospaceIndustry Standards Committee, was published under the authorityof the Executive Board of the Institution on 21March 1972 BSI 03-1999 The following BSI references relate to the work on this standard: Committee reference ACE/58 Draft for comme
3、nt 70/26884 ISBN 580 6879 Foreword This British Standard is part of a composite standard in the Aerospace Series of British Standards specifying general requirements for equipment in aircraft. An introduction to the complete standard is given in BS 3G.100-0:Introduction. This subsection of BS 3G.100
4、 supersedes the low pressure test specified in Clause 206 iv) of BS 2G.100-2. It details tests for three types of differential pressure conditions: namely excess pressure, rapid decompression and explosive decompression, which may be applied to some of the various grades of equipment and classes of
5、aircraft listed in BS 3G.100:2:3.2. An appendix stating conversions of the SI units is included for the assistance of readers. This standard makes reference to the following: BS3G.100-0, Introduction. BS3G.100-2.3.0, Standard test requirements 1) . BS3G.100-2.3.2, Temperature-pressure requirements.
6、NOTEInformation regarding metric (SI) units is given in BS 3763 “The International System of units (SI)” and BS 350 “Conversion factors and tables”. A British Standard does not purport to include all the necessary provisions of a contract. Users of British Standards are responsible for their correct
7、 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, pages i and ii, pages 1 to 5 and a back cover. This standard has been updated (see copyright date) and may have h
8、ad amendments incorporated. This will be indicated in the amendment table on the inside front cover. 1) In course of preparation. Amendments issued since publication Amd. No. Date CommentsBS3G.100-2.3.4:1972 BSI 03-1999 i Contents Page Foreword Inside front cover 1 Scope 1 2 General test requirement
9、s 1 2.1 Test requirements 1 2.2 Special precautions 1 3 Excess pressure test 1 3.1 General 1 3.2 Field of application 1 3.3 Test procedure 1 3.4 Test conditions 1 3.5 Information to be specified in the relevant equipment specification 1 4 Rapid decompression test 2 4.1 General 2 4.2 Test procedure 2
10、 4.3 Test conditions 2 4.4 Information to be specified in the relevant equipment specification 2 5 Explosive decompression test 3 5.1 General 3 5.2 Field of application 3 5.3 Test procedure 3 5.4 Test conditions 3 5.5 Information to be specified in the relevant equipment specification 3 Appendix A G
11、uidance for the conduct of the rapid decompression test 4 Appendix B Guidance for the conduct of the explosive decompression test 4 Appendix C Conversion of pressure units 5 Table 1 Pressures for excess pressure tests 1 Table 2 Pressures for rapid decompression tests 2 Table 3 Pressures for explosiv
12、e decompression tests 3 Table 4 Conversion table of pressure units 5ii blankBS3G.100-2.3.4:1972 BSI 03-1999 1 1 Scope This subsection of BS3G.100-2 describes tests to evaluate the effects of various pressure differential effects upon components or equipment used in aircraft. It should also be read i
13、n conjunction with BS 3G.100-0. Three different tests are stated each of which has a specific field of application. The relevant equipment specification will prescribe the test(s) to be used and also the appropriate functional checks. 2 General test requirements 2.1 Test requirements. For the purpos
14、es of this standard the appropriate requirements stated in BS3G.100-2.3.0 2) shall apply. 2.2 Special precautions. To avoid damage during the tests equipment having connections to the atmosphere external to the aircraft, e.g. altimeters, airspeed indicators, mach-meters, etc., shall be so connected
15、as to simulate such conditions. 3 Excess pressure test 3.1 General. An excess pressure test is applicable to equipment mounted within the pressurized zone of an aircraft, its purpose being to demonstrate that the equipment will not be deranged by positive air pressure applied when ground testing air
16、craft pressure cabins. 3.2 Field of application. An excess pressure test need only be applied to equipment having sealed enclosures (either pressurized or evacuated) or partially sealed enclosures having low leakage rates, which might be affected by an excess pressure condition. 3.3 Test procedure 3
17、.3.1 Equipment normally pressurized or evacuated shall have the internal pressure adjusted to the most adverse design limit that would be experienced at ground level. 3.3.2 The equipment shall be placed in the test chamber and orientated into its normal attitude if this is significant, as required b
18、y the relevant specification. 3.3.3 The test chamber shall be conditioned for a period sufficient to allow the equipment to stabilize at the test temperature stated in 3.4.1. 3.3.4 The pressure within the chamber shall then be increased by the appropriate differential test pressure stated in 3.4.2 i
19、n a period of not less than5 minutes, nor longer than 15 minutes. 3.3.5 The pressure shall be maintained at this level for a period of not less than 30 minutes, and shall finally be restored to standard laboratory conditions in a period of not less than 5 minutes and not greater than 15 minutes. 3.3
20、.6 The equipment shall be subjected to this test in its idle or inert condition, unless it is a functional part of the aircraft during a pressurization check. In this event the equipment should be operated and made to function in the representative manner required by the relevant equipment specifica
21、tion. 3.4 Test conditions 3.4.1 The test shall be applied initially with the temperature corresponding to standard laboratory conditions; and additionally at 20C or +70 C, or both, if temperature is likely to contribute to failure. 3.4.2 The appropriate test pressure for the equipment grades and rel
22、evant class 3) of aircraft covered by this test are as shown in Table 1. Table 1 Pressures for excess pressuretests 3.5 Information to be specified in the relevant equipment specification. When an excess pressure test is specified in a relevant specification the following details shall be stated, as
23、 far as they are applicable: 1) Mounting of equipment in the chamber (see 3.3.2 and 2.1). 2) Test severities, e.g. testtemperature(see3.3.3) testpressure(see3.3.4). 3) Operative condition of the equipment (see 3.3.6). 4) The phases of the test when performance checks shall be made (see 2.1). 2) In c
24、ourse of preparation. The requirements of BS 3G.100-2.3.2, Clauses 5.1, 5.2 and 5.4 etc. may be used in the interim. 3) The equipment grades stated here and the relevant class of aircraft correspond with those given in BS 3G.100-2.3.2 for temperature-pressure requirements. Relevant equipment grade a
25、 Max. pressure differential kN/m 2 (see Note 1) Differential test pressure kN/m 2(see Note 2) A 76 85 Q 36 41 NOTE 1In the test conditions stated above, the pressurization level for ground testing has been assumed equal to the maximum level occurring in flight for the particular class of aircraft. N
26、OTE 2The test pressure is based on a proof test concept and is the maximum pressure differential factored by 1.125. a The equipment grades stated here and the relevant class of aircraft correspond with those given in BS 3G.100-2.3.2 for temperature-pressure requirements.5 +0 %BS3G.100-2.3.4:1972 2 B
27、SI 03-1999 4 Rapid decompression test 4.1 General. A rapid decompression test is applicable to equipment mounted within the pressurized zone of an aircraft. Its purpose is to demonstrate that, in the event of a pressurization supply failure or a structural failure of the aircraft causing a rapid but
28、 not explosive loss of pressurization, the equipment will survive or will fail in such a manner so as not to hazard the safety of the aircraft. Guidance in the conduct of rapid decompression tests is given in Appendix A. 4.2 Test procedure 4.2.1 Equipment normally pressurized or evacuated shall have
29、 the internal pressure adjusted to the most adverse design limit that would be experienced at ground level. 4.2.2 The equipment shall be placed in the test chamber and orientated into its normal attitude if this is significant, as required by the relevant specification. 4.2.3 The test chamber shall
30、be conditioned for a period sufficient to allow the equipment to stabilize at the test temperature stated in 4.3.1. 4.2.4 The pressure within the chamber shall then be reduced to the appropriate pressurization level stated in 4.3.2, and shall be maintained at this level for a period of not less than
31、 5 minutes. 4.2.5 The pressure shall then be further reduced to that corresponding to the appropriate maximum flight altitude stated in 4.3.2. in a period not exceeding one minute, or if allowed by the relevant specification at the maximum rate of change obtainable from the test chamber (see also Ap
32、pendix A). 4.2.6 The pressure shall then be maintained at this level for a period not less than 10 minutes, or as required by the relevant specification. 4.2.7 The relevant specification may require the temperature to be changed to simulate temperature levels resulting from pressurization failure, a
33、nd/or the pressure to be increased to simulate descent to a more acceptable flight altitude. The relevant specification will state the conditioning required. 4.2.8 The equipment, unless the test is being made with equipment in its idle or inert state, shall be operated and its performance checked at
34、 the phases of the test stated in the relevant specification. 4.3 Test conditions 4.3.1 The test should be applied initially with the temperature corresponding to standard laboratory conditions; and additionally at +45C or 20C, or both, if temperature is likely to contribute to failure. 4.3.2 The ap
35、propriate pressure requirements for the equipment grades and relevant class 4) , of aircraft covered by this test are as shown in Table 2. Table 2 Pressures for rapid decompression tests 4.4 Information to be specified in the relevant equipment specification. When a rapid decompression test is speci
36、fied in a relevant equipment specification the following details shall be stated, as far as they are applicable: 1) Whether the test is a demonstration of performance or survival (see 4.1). 2) If performance is to be checked, the phase(s) of the test cycle when the equipment is to be operated and th
37、e performance checks to be carried out (see 4.2.8 and 2.1) 3) Mounting of equipment in the chamber (see 4.2.2 and 2.1). 4) Test severities, e.g. pressurization level (see 4.2.4) test pressures related to maximum flight altitude (see 4.2.5) temperature(s) (see 4.2.3). 5) Whether a rate of change lowe
38、r than 1 minute is allowed (see 4.2.5). 6) Duration of maximum flight altitude (see 4.2.6). 4) The equipment grades stated here and the relevant class of aircraft correspond with those given in BS 3G.100-2.3.2 for temperature-pressure requirements. Relevant equipment grade a Use in aircraft class a
39、Pressurization level kN/m 2absolute (see Note below) Test pressure related to max. flight altitude kN/m 2absolute 5 % A II 87.5 11.5 IV 80.5 4.5 Q II 51.5 11.5 III 47.0 7.0 IV 44.5 4.5 NOTEThe test conditions stated above are based upon a pressurization where the differential is 76 kN/m 2for Grade A
40、 equipment and 36 kN/m 2for Grade Q equipment.In the latter case the figure has been increased to 40 kN/m 2 to allow for suction effects. a The equipment grades stated here and the relevant class of aircraft correspond with those given in BS 3G.100-2.3.2 for temperature-pressure requirements.5 +0 %B
41、S3G.100-2.3.4:1972 BSI 03-1999 3 7) Conditioning following decompression phase, stating temperature and pressure (see 4.2.7). 5 Explosive decompression test 5.1 General. The explosive decompression test is applicable to some types of Grade Q equipment. Its purpose is to demonstrate that, in the even
42、t of a structural failure of the aircraft causing an explosive loss of pressurization, such equipment will survive or will fail in a manner that does not hazard the safety of the aircraft. Guidance in the conduct of explosive decompression tests is given in Appendix B. 5.2 Field of application. Expl
43、osive decompression is significant for that equipment where the violent change of pressure would create abnormal stressing, such as equipment of sealed, semi-sealed, or restricted vent (breathing tube) design, or containing components and assemblies of such design. For other equipments where the vio
44、lent change of pressure is not significant the effects of pressure change may be demonstrated by the rapid decompression test given in Section 4 of this standard. 5.3 Test procedure 5.3.1 Equipment which is normally pressurized or evacuated shall have the internal pressure adjusted to the most adver
45、se design limit that would be experienced at ground level. 5.3.2 The equipment shall be placed in the test chamber and orientated into its normal attitude if this is significant, as required by the relevant specification. 5.3.3 The test chamber shall be conditioned for a period sufficient to allow t
46、he equipment to stabilize at the test temperature stated in 5.4.1. 5.3.4 The pressure within the chamber shall then be reduced to the appropriate pressurization level stated in 5.4.2, and shall be maintained at this level for a period of not less than 5 minutes. 5.3.5 The pressure shall then be furt
47、her reduced to that corresponding to the appropriate maximum flight altitude in a period not exceeding 100ms. 5.3.6 The pressure shall then be maintained at that level for a period not less than 10 minutes, or as required by the relevant specification. 5.3.7 The relevant specification may require th
48、e temperature to be changed to simulate temperature levels resulting from pressurization failure and/or the pressure to be increased to simulate descent to a more acceptable flight altitude. The relevant specification shall state the conditioning required. 5.3.8 The equipment, unless the test is bei
49、ng made with equipment in its inert or idle state, shall be operated and its performance checked at the phases of the test stated in the relevant specification. 5.4 Test conditions 5.4.1 The test should be applied, initially with the temperature corresponding to standard laboratory conditions; and additionally at 45C or 20C, or both, if temperature is likely to contribute to failure. 5.4.2 The appropriate pressure requirements for the equipment grades and relevant class of aircraft covered by this test are as shown in Table 3. Table 3 Pressures for
