1、BRITISH STANDARD AEROSPACE SERIES BS3F63:1981 (Superseding BS2F63:1967) Incorporating Amendment Nos.1 and2 Specification for Low pressure oxygen hose for aeronautical purposes UDC629.7.048.4:621.643.3984BS3F63:1981 This BritishStandard, having been prepared under the directionof the Aerospace Standa
2、rds Committee, was published under the authority ofthe Executive Board on 30October1981 BSI02-2000 The following BSI references relate to the work on this standard: Committee reference ACE/25 Draft for comment80/71807 DC ISBN 0 580 12366 9 Foreword This BritishStandard was first published in1957. It
3、 was revised in1967 to permit the use of certain synthetic rubbers in addition to natural rubber, and to include additional requirements relating to the limits on the compression set and the approval in respect of freedom from odour. This revision updates the requirements and introduces metric units
4、. The requirement to produce the hose in standard lengths is now thought to be unrealistic and has been deleted. The purchaser is required to specify the lengths required in the contract or order. A British Standard does not purport to include all the necessary provisions of a contract. Users of Bri
5、tish Standards are responsible for their 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, pagesi andii, pages1 to7 and a back cover. This standard has been
6、 updated (see copyright date) and may have had amendments incorporated. This will be indicated in the amendment table on the inside front cover. Amendments issued since publication Amd. No. Date of issue Comments 4554 May 1984 6029 May 1989 Indicated by a sideline in the marginBS3F63:1981 BSI 02-200
7、0 i Contents Page Foreword Inside front cover 1 Scope 1 2 References 1 3 Construction 1 4 Materials 1 5 Dimensions 2 6 Mass 2 7 Freedom from defects 2 8 Freedom from odour 2 9 Tests on finished hose 2 10 Freedom from foreign matter 2 11 Packaging and identification 2 12 Approval of rubber mixes 5 13
8、 Routine inspection and sampling 5 Appendix A Method of test for freedom from porosity 7 Appendix B Method of test for flexibility 7 Appendix C Method of test for resistance to splitting and kinking 7 Figure 1 Low pressure oxygen hose for aircraft 3 Figure 2 Gauge for plain ends 4 Figure 3 Bore cons
9、triction test bob 5 Table 1 Rubber mix requirements 4ii blankBS3F63:1981 BSI 02-2000 1 1 Scope This BritishStandard specifies the requirements for the construction, dimensions, testing and marking of corrugated rubber hose (generally known as Mark5A hose), of16mm internal diameter, used on aircraft
10、to deliver oxygen and air, at pressures up to0.35bar 1) , from pick-up points on the aircraft oxygen supply system to the aircrew harness. The hose is suitable for use at temperatures between40 C and+70 C. 2 References This standard makes reference to the following standards publications BS 4F55, Me
11、dium mass cotton fabric. BS 3F68, Specification for controlled storage of vulcanized rubbers for use in aerospace applications. BS 3F69, Specification for packaging and identification of vulcanized rubber items. BS 3N100, Specification for general design requirements for aircraft oxygen systems and
12、equipment. BS903, Methods of testing vulcanized rubber Part A1: Determination of density PartA2:Determination of tensile stress-strain properties Part A6: Determination of compression set after constant strain Part A13: Determination of the stiffness of vulcanized rubbers at low temperatures (Gehman
13、 test) Part A19: Heat resistance and accelerated air ageing tests PartA26: Determination of hardness. BS3592, Steel wire for rubber hose reinforcement Part2: Coated patented steel wire. The latest editions of these standards shall be used. 3 Construction 3.1 The hose shall be mandrel-built. It shall
14、 have a lining of rubber with a helix of steel wire sealed between the lining and a second layer of rubber. The second layer shall be enclosed in a cover of woven fabric. The whole shall be firmly and uniformly vulcanized so that the cover forms corrugations due to the embedded wire. (See Figure 1.)
15、 3.2 The rubber lining shall be a smooth, continuous, extruded tube. 3.3 The second layer of rubber shall be applied by wrapping with a single longitudinal overlap of7mm to10mm. 3.4 The cover fabric shall be cut on the bias and applied over the second layer of rubber as a single ply with a longitudi
16、nal overlap of3.5mm to7mm. Any joins in the cover shall run in the warp direction of the fabric, i.e.spirally round the hose, and shall have an overlap of3.5mm to7mm. There shall be not more than one such join in hoses up to and including1.6m in length nor more than two in hoses greater than1.6m in
17、length. 3.5 The cover shall be firmly attached to the second layer and to itself at overlaps by means of the rubber mix specified for the second layer, applied as a solution. The solution edge shall extend3.5mm to7mm beyond the join on the external surface. 3.6 The reinforcing wire shall be uniforml
18、y wound at135 6 turns per metre length of helix. 3.7 Each end of the hose shall be free of wire but shall be reinforced with a single ply of light woven fabric. This fabric shall be cut on the bias and applied between the two rubber layers, extending from the end of the hose over not less than two b
19、ut not more than four complete turns of the wire, with a longitudinal overlap of7mm to15mm. It shall be firmly attached to the rubber on either side by means of the same rubber solution as used for attaching the cover and shall hold the cut end of the wire firmly in position. 3.8 Each and every hose
20、 shall comply with BS3N100 in respect of workmanship, material and finish. 4 Materials 4.1 Rubber mixes 4.1.1 Before any manufacturers hose can be considered for compliance with the requirements of this standard, the rubber mixes shall have received approval. (See clause12 for the procedure for appr
21、oval of rubber mixes.) 4.1.2 The rubber mixes used for the lining and second layer shall be based on natural or synthetic polyisoprene rubber and may contain a proportion of polybutadiene or styrene butadiene rubber, and shall be compounded with ingredients such that the resultant vulcanizate has no
22、 pronounced odour. The mixes shall also contain at least1 part by mass of suitable antioxidant per100 parts by mass of rubber hydrocarbon. 4.1.3 The mixes shall comply with the relevant requirements shown in Table 1 and shall be substantially non-blooming. 4.1.4 The rubber mix used for the lining of
23、 the hose shall comply with4.1.4 of BS3N100:1985. 1) 1bar=10 5 N/m 2 =100kPa.BS3F63:1981 2 BSI 02-2000 4.2 Steel wire. The wire shall be galvanized wire1.250mm diameter and1250N/mm 2to1400N/mm 2tensile strength, complying with the requirements of BS3592-2. 4.3 Woven fabrics. The fabric for the cover
24、 and cuffs shall be cotton fabric No.448 in accordance with BSF55 dyed, in accordance with that standard, with a suitable black dye such that it shows no reflection in red light and no fluorescence in ultra-violet light. 5 Dimensions 5.1 Length. The hose shall be in lengths as specified in the contr
25、act or order. The tolerances on the nominal length shall be+0.05,0.03m. 5.2 Other dimensions. All other dimensions and tolerances shall be as shown in Figure 1. 6 Mass The mass of the hose shall be not greater than0.29kg/m length. 7 Freedom from defects The hose shall be free from malformation, weak
26、 or lifting joins, lack of adhesion between layers, thin places in rubber layers or other visible defects likely to affect its service life or utility. 8 Freedom from odour The hose shall be free from odour other than that of the rubber mixes defined in4.1, e.g.from traces of any solvents used durin
27、g manufacture. 9 Tests on finished hose 9.1 Acceptance of end fittings. Each plain end of each hose shall allow the gauge shown in Figure 2 to be inserted so that the forward narrow part of the gauge enters the wire reinforced part of the hose without damage to the hose. 9.2 Freedom from internal co
28、nstriction. The hose shall allow a brass bob of the form and dimensions shown in Figure 3 to fall readily through it when the hose is suspended vertically from one end. 9.3 Freedom from porosity. When determined by the method described in Appendix A, any fall in air pressure in the hose shall be not
29、 greater than1mmHg. 9.4 Flexibility. The flexibility of the hose at normal temperature shall be such that, when tested as described in Appendix B, the free end of the hose shall bend to a level at least as low as the top of the supporting tube. 9.5 Resistance to splitting and kinking. After subjecti
30、on to the treatment described in Appendix C, the hose shall still comply with the requirements of clause7, 9.2 and9.3. 10 Freedom from foreign matter On completion of examination and testing, the interior of each hose shall be freed from dust, French chalk or other loose particles by blowing through
31、 with clean dry air while the hose is being carefully shaken or knocked to dislodge the particles. The hose shall also be free of other contamination resulting from the use of release agents during manufacture. The ends of the hose shall then be suitably sealed to prevent contamination. 11 Packaging
32、 and identification 11.1 The hose shall be packaged and identified in accordance withBS 3F69. A thin, white flexible label shall be firmly bonded near to each end of the hose, clear of the plain end and following the corrugations. Alternatively, by agreement with the Quality Assurance Authority, a l
33、abel of heat shrinkable material not exceeding30mm in length may be used. 11.2 Each label shall be marked in a bold and durable manner with the following details. a) The number of this BritishStandard (i.e.BS3F63) 2) . b) The length of the hose in metres. c) The manufacturers identity. d) The quarte
34、r and year of manufacture (e.g.4Q81). e) The batch number. f) The life grouping in accordance with the requirements ofBS 3F68. 2) Marking BS2F63 on or in relation to a product is a claim by the manufacturer that the product has been manufactured in accordance with the requirements of the standard. T
35、he accuracy of such a claim is therefore solely the manufacturers responsibility. Enquiries as to the availability of third party certification to support such claims should be addressed to the Director, BritishStandards Institution, Maylands Avenue, Hemel Hempstead, Herts HP24SQ in the case of cert
36、ification marks administered by BSI or to the appropriate authority for other certification marks.BS 3F 63:1981 BSI 02-2000 3 Figure 1 Low pressure oxygen hose for aircraftBS3F63:1981 4 BSI 02-2000 Table 1 Rubber mix requirements Property Requirement Method of test a) Colour 1) Lining: White to pale
37、 brown 2) Second layer: Black b) Hardness, IRHD c) Density at23 C,Mg/m 3 45 4 Nominal value a 0.02 BS903-A26, using one piece of the thicker part of the test sheet superimposed on one piece of the thinner part BS903-A1, method A d) Tensile strength, MPa, minimum e) Elongation at break,%, minimum 20
38、600 BS903-A2, dumb-bell test pieces f) Resistance to accelerated ageing: 1) change in tensile strength,% of original value, maximum 2) change in elongation at break,% of original value, maximum 20 0 20 BS903-A19. Test pieces aged at70 C for168h by method A or B g) Compression set,%, maximum h) Resis
39、tance to low temperature, the stiffness at50 C, MPa maximum 25 70 BS903-A6, method A, using type1, lubricated test pieces,22h compression at70 C BS903-A13 a To be agreed between the manufacturer and the Quality Assurance Authority. Figure 2 Gauge for plain endsBS3F63:1981 BSI 02-2000 5 12 Approval o
40、f rubber mixes 12.1 Before any manufacturers mix can be considered for compliance with the requirements of this standard the rubber mixes shall have received approval. To obtain approval the manufacturer shall provide the Quality Assurance Authority 3)with the following. a) A declaration, in confide
41、nce, of the detailed composition of the mix together with a1kg sample of the unvulcanized mix. b) The proposed conditions of vulcanization (time and temperature), for the two-thickness test sheets prepared from each mix (see13.2.1), together with the value of the nominal density for the test sheets.
42、 (See Table 1.) c) A two-thickness test sheet prepared from the mix under the proposed conditions of12.1 b), together with test results obtained on a similar test sheet in order that tests may be carried out by the Approving Authority. These will include testing for freedom from odour. d) A certific
43、ate of compliance with4.1.4 of BS3N100:1985 for the rubber material proposed for the lining of the hose. 12.2 After formal approval has been given, no change in the composition or departure from the agreed proposals of12.1 b) shall be made without the prior agreement of the Quality Assurance Authori
44、ty. 13 Routine inspection and sampling 13.1 General. Unless otherwise agreed with the Quality Assurance Authority, a batch of hose shall consist of all hoses produced from one uniform batch of each rubber mix and vulcanized under the same conditions. 13.2 Rubber mixes From each batch of rubber mix,
45、a two-thickness test sheet of the following dimensions shall be prepared and tested in accordance with the requirements given in Table 1. The sheet shall be approximately250mm square with a section along one side35mm to50mm wide and6.30 0.15mm thick. The remainder of the sheet shall be2.00 0.15mm th
46、ick. If desired part of the6.3mm section may be moulded in the form of cylindrical buttons complying with the requirements of the type1 test piece as defined in PartA6 of BS903 for the purpose of compression set tests. When such buttons are moulded the cavities shall be individually charged with pel
47、lets and not by the flow of the excess rubber from the remainder of the mould. The minimum number of buttons moulded shall be nine and they shall be in a group at one end of the6.3mm section. The test sheet shall be vulcanized at a temperature appropriate for the mix. No additional vulcanization sha
48、ll be applied to the thicker section (or buttons) of the sheet in any way whatsoever. NOTEThe frequency of testing to any single requirement may be reduced by agreement between the manufacturer and the Quality Assurance Authority. Such an agreement should be based on the uniformity of quality and th
49、e frequency of production of the mix. 13.3 Hose 13.3.1 Each hose shall be examined and tested for compliance with the requirements of clause5 (as far as possible), clause7, 9.1, 9.2, 9.3 and clause11 and, subsequent to cleaning and sealing in accordance with clause10, examined for soundness of seals. 13.3.2 At least two hoses selected at random from each batch shall be tested for compliance with the requirements of clause6, 9.4 and9.5. Figure 3 Bore constriction test bob 3) For MOD contracts, such approv
