1、BRITISH STANDARD BS3G 100-2.3.12: 1991 Specification for General requirements for equipment for use on aircraft Part 2: All equipment Section 3: Environmental conditions Subsection 3.12 Fluid contaminationBS3G 100-2.3.12:1991 This British Standard, having been prepared under the directionof the Aero
2、space Standards Policy Committee, waspublished under the authorityof the Standards Boardand comes into effect on 31May1991 BSI 02-1999 First published October1973 Second edition September1986 Third edition May1991 The following BSI references relate to the work on this standard: Committee reference
3、ACE/58 Draft for comment89/78555DC ISBN0 580 19118 4 Committees responsible for this British Standard The preparation of this British Standard was entrusted by the Aerospace Standards Policy Committee (ACE/-) to Technical CommitteeACE/58, upon which the following bodies were represented: Civil Aviat
4、ion Authority The Electronics and Business Equipment Association (EEA) Ministry of Defence Society of British Aerospace Companies Limited Society of Environmental Engineers Amendments issued since publication Amd. No. Date CommentsBS3G 100-2.3.12:1991 BSI 02-1999 i Contents Page Committees responsib
5、le Inside front cover Foreword ii 1 Scope 1 2 Test fluid 1 3 Test samples 1 4 Cleaning 1 5 Initial examination 1 6 Test procedures 1 7 Occasional contamination (class A) 1 8 Intermittent contamination (class B) 3 9 Extended contamination (class C) 3 10 Final examination 3 11 Information to be suppli
6、ed in the product specification 3 Appendix A Guidance on the choice of test fluids and test materials 4 Table 1 Major contaminant fluid groups and test fluids 2 Publication(s) referred to Inside back coverBS3G 100-2.3.12:1991 ii BSI 02-1999 Foreword This British Standard, which has been prepared und
7、er the direction of the Aerospace Standards Policy Committee, 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 British Standard is given in British Standard3G100-0. The tests descri
8、bed in this standard should be specified when there is a real risk of fluid contamination, either occasional, intermittent or extended, under normal conditions of operation. They are normally required where no evidence of previous satisfactory testing is available or where required for quality assur
9、ance purposes. This revision supersedes Subsection3.12:1986, which is withdrawn. The major changes in the revision are as follows: a) the adoption, where possible, of standard test fluids in place of commercial fluids; b) the inclusion of an appendix to assist in the choice of test fluids and test p
10、rocedures. WARNING. This standard calls for the use of substances and/or test procedures that may be injurious to health if adequate precautions are not taken. It refers only to technical suitability and in no way absolves either the supplier or the user from statutory obligations relating to health
11、 and safety at any stage of manufacture or use. A British Standard does not purport to include all the necessary provisions of a contract. Users of British Standards are responsible for their correct application. Compliance with a British Standard does not of itself confer immunity from legal obliga
12、tions. Summary of pages This document comprises a front cover, an inside front cover, pages i and ii, pages1to6, an inside back cover and a back cover. This standard has been updated (see copyright date) and may have had amendments incorporated. This will be indicated in the amendment table on thein
13、side front cover.BS3G 100-2.3.12:1991 BSI 02-1999 1 1 Scope This British Standard specifies tests to demonstrate that the equipment including materials, components or sub-assemblies (incorporating joints, welds or bonds) from which the equipment is constructed will not be unacceptably affected by co
14、ntaminating fluids to which it or they may be exposed. It should be read in conjunction with British Standard3G100-0. The fluids listed in this standard are representative of those commonly encountered in operational applications. Fluids not listed and for which a test is required should be included
15、 in the product specification. These tests are not intended to demonstrate the suitability of an equipment or component to perform in continuous contact with a fluid, e.g.an immersed fuel pump. Nor are they a test to demonstrate immunity from electrolytic corrosion. NOTEThe titles of the publication
16、s referred to in this standard are listed on the inside back cover. 2 Test fluid The product specification (see clause 11) shall specify the required test fluids which shall wherever possible be selected from the list given in Table 1. Each fluid has been specified as being representative of a group
17、 of fluids. NOTESee A.2. The product specification shall also specify any additional fluids not listed in Table 1 for which a test is required. 3 Test samples 3.1 The test sample shall be either: a) an equipment; or b) a component. NOTE 1Where size or availability of an equipment does not permit a f
18、ull test, a specially selected representation of materials, finishes and components used in an equipment may be used as a test sample. NOTE 2Test samples for materials or finishes should have a minimum surface area, where possible, of20cm 2 . 3.2 The product specification shall specify the number an
19、d type of samples to be tested. NOTESee A.4. 4 Cleaning NOTESee A.5. 4.1 Initial cleaning Unless otherwise specified in the product specification the test sample shall be thoroughly cleaned to remove unrepresentative coatings i.e.preservatives, grease or contaminants. 4.2 Intermediate cleaning If se
20、quential testing is required, the product specification shall specify any necessary cleaning method. 4.3 Final cleaning The product specification shall specify any necessary cleaning method prior to final examination. 5 Initial examination 5.1 The test sample shall be visually examined and its condi
21、tion recorded. 5.2 The product specification shall specify any measurements or tests required. NOTESee A.6. 6 Test procedures 6.1 Three test procedures are given in clauses 7 to 9. The product specification shall specify the test or tests to be used and the order of application of the test fluids if
22、 sequential testing is required. NOTESee A.7. 6.2 The product specification shall specify whether the test sample is to be connected electrically or mechanically and, if it is required to operate before, during or after the procedure, the operating parameters shall also be defined. 7 Occasional cont
23、amination (class A) 7.1 Mount the test sample in its normal operating configuration and maintain at room temperature, or as specified in the product specification. 7.2 Dip, brush or spray the test sample with the specified fluid which shall be maintained at the test temperature given in Table 1, or
24、as specified in the product specification. Ensure that the entire surface of the sample is thoroughly wetted. Allow the sample to drain naturally for5min to10min; shaking or wiping is not permitted. 7.3 Transfer the test sample to a suitable test chamber and maintain at the test temperature for the
25、time specified in the product specification. If not specified, the parameters shall be70 2 C for933h. 7.4 At the end of the period allow the test sample to cool to room temperature before being subjected to final examination. 7.5 Repeat this procedure, if specified by the product specification.BS3G
26、100-2.3.12:1991 2 BSI 02-1999 Table 1 Major contaminant fluid groups and test fluids Contaminant fluid group Test fluid ref Test fluid Test temperature a( 2 C) Fuels Kerosene (turbine) a) ISO1817 test liquid F 70 b Gasoline (piston engine) b) ISO1817 test liquid B 40 b Hydraulic fluids Mineral oil b
27、ased c) NATOH-520; (OM-18) c 70 Phosphate ester based (synthetic) d) ISO1817 test liquid103 70 Silicone based e) Dimethyl silicone, 10mm 2 /s (cSt) at25C (ZX42; NATO S1714) 70 Lubricating oils Mineral based f) NATO0-1176 (OMD80) 70 Ester based (synthetic) g) ISO1817 test liquid101 150 Solvents and c
28、leaning fluids h) Propan-2-ol (isopropyl alcohol) (seeBS1595) 50 b i) 1,1,1-Trichloroethane (see BS4487) d 50 j) De-natured alcohol (see BS3591) 23 k) Detergent (see TS10281) 23 De-icing and anti-freeze fluids l) Inhibited ethanediol (ethylene glycol) (seeBS6580) 80% solution in water (V/V) 23 m) In
29、hibited ethanediol (ethylene glycol) (seeBS6580) 50% solution in water (V/V) 23 Runway de-icers n) 25% urea/25% ethanediol (ethyleneglycol) in water d 23 o) 50% inhibited potassium acetate in water d 23 Insecticides p) Dichlorvos (DDVP) pyrethrum based,2% solution in kerosene 23 q) D-phenothrin2% so
30、lution in kerosene 23 Sullage r) 4 0.1% Formaldehyde plus 1 0.1% o-Cresol (general purpose reagent) in water 23 Coolant dielectric fluid (SeeA.2.10) s) Coolanol 25R (see DTD900/4931) 70 Fire extinguishants t) Fluorochemical foam (rapid intervention) 23 u) Fluoroprotein foam 23 NOTEFor information on
31、 the availability of the liquids given in this table, write to Customer Information, BSI, Linford Wood, Milton Keynes MK14 6LE. a See clauses 7, 8 and 9 and A.7. b This temperature exceeds the critical flash point temperature. Expert advice should taken on the conduct of the test. c NATO H-515 may b
32、e used as an alternative if desired. d Subject to possible change (seeA.3).BS3G 100-2.3.12:1991 BSI 02-1999 3 8 Intermittent contamination (class B) 8.1 Mount the test sample in its normal operating configuration and maintain at room temperature, or as specified in the product specification. 8.2 Dip
33、, spray or brush the test sample with the specified fluid which shall be maintained at the test temperature given in Table 1, or as specified in the product specification. Ensure that the entire surface of the sample is wetted. Repeat this procedure one or more times as necessary to maintain all the
34、 test sample surfaces in a wetted condition for the period prescribed in the product specification. If the period is not specified it shall be three cycles each of241h. Each cycle shall consist of8 0.5h in the fully wetted condition followed by a drain period of16 0.5h at ambient temperature during
35、which no additional wetting shall occur. 8.3 Transfer the test sample to a suitable test chamber and maintain at the test temperature and for the time specified in the product specification. If not specified, the parameters shall be70 2 C for933h. 8.4 At the end of the period allow the test sample t
36、o cool to room temperature before being subjected to final examination. 9 Extended contamination (class C) NOTEThis procedure is not intended to demonstrate the operation of an equipment which is normally immersed in a fluid. 9.1 Immerse the test sample fully in the specified test fluid which shall
37、be maintained at the temperature and for the time stated in the product specification. If the temperature and/or duration are not specified, the temperature shall be as given in Table 1, and the duration shall be a minimum of241h. 9.2 Transfer the test sample to a suitable test chamber and maintain
38、at the test temperature and for the time specified in the product specification. If not specified, the parameters shall be70 2 C for933h. 9.3 At the end of the period allow the test sample to cool to room temperature before being subjected to final examination. 10 Final examination 10.1 The test sam
39、ple shall be cleaned in accordance with 4.3. 10.2 Examine the test sample visually and record any change of condition from the initial examination. 10.3 The product specification shall specify any measurements or tests required. NOTESeeA.6. 11 Information to be supplied in the product specification
40、The following information shall be supplied in the product specification: a) test fluids to be used (see clause2); b) details of test sample(s) (see clause3); c) cleaning procedure if required (see clause4); d) initial examination (see clause5); e) test procedure(s) to be used (see6.1); f) order of
41、application of fluids for sequential test if applicable (see6.1); g) connections and operations during the test procedure(s) if required (see6.2); h) test sample configuration and initial temperature if other than normal operating configuration at room temperature (see7.1 and8.1); i) test fluid temp
42、erature if other than in Table 1 (see clauses7, 8 and 9); j) duration of fluid application/immersion and storage temperature during fluid application (seeclauses7, 8 and 9): k) chamber storage temperature and/or time after fluid application (see clauses7, 8 and 9); l) final examination (see clause10
43、).BS3G 100-2.3.12:1991 4 BSI 02-1999 Appendix A Guidance on the choice of test fluids and test materials A.1 General The test procedures detailed in this standard are intended to determine the effects on equipments of contamination by fluids. It may be appropriate to carry out a test or sequence of
44、tests on the equipment itself, on subsystems, components or materials, depending on the likelihood of contamination and the possible effects arising. Fluids, application procedures and test conditions should be chosen as far as possible to represent typical worst case real life situations. A.2 Conta
45、minating fluids and their effects A.2.1 General A.2.1.1 Components and equipment used in aircraft may be subjected to contamination by fluids, either through normal operation, accidental spillage or through leakage from faulty pipes or pipe joints. A.2.1.2 The contaminating fluid may not be at an el
46、evated temperature, but a component or equipment may become contaminated while itself at its elevated working temperature or it may attain such a temperature after having been contaminated. Any effect may thus depend upon the behaviour of the contaminant at elevated temperature,e.g.if it is volatile
47、 it may disappear rapidly. If it is non-volatile and slowly oxidizes, a hard residue may remain A.2.1.3 Effects which may occur include packaging failure, crazing or swelling of plastics and rubbers, leaching of anti-oxidants and other soluble materials, seal failures, adhesion failures, paint/legen
48、d removal and corrosion. A.2.2 Fuels In most cases fuels will be of the gasoline or kerosene type. The former may be expected to evaporate rapidly, possibly with few permanently harmful effects, whereas the latter being more persistent, will be damaging to many elastomers, particularly at elevated t
49、emperature. Paints and most plastics are not normally affected by fuels, but silicone resin bonded boards may tend to de-laminate after prolonged exposure. Some fuels may have additives to inhibit icing, or to dissipate static charges. Where there is reason to suppose that these additives may increase the severity of the test, they should be included in the test fluids. A.2.3 Hydraulic fluids Commonly used hydraulic fluids, may be of the mineral oil or ester-based synthetic type, the latter are damaging to most elastomers and to plastics. Phosphate est
