1、- BSI 3F*65 91 M 1624669 0239896 7 E BRITISH STANDARD AEROSPACE SERIES Specification for Flexible corrugated oxygen and air tubes for aircraft (natural or synthetic polyisoprene) Srie aerospatiale. Spcification pour les tubes onduls souples oxygne et air pour laronautique (polyisoprne naturel ou syn
2、thtique) Luft-und Raumfahrt-Reihe, Spezifikation fr Faltenschiuche fr Sauerstoff und Luft fr Flugzeuge (Natur- oder Kunstpolyisopren) BS 3F 65 : 1991 (Superseding BS 23 65 : 1981) t ES1 3F*b5 91 1b24bb9 0239897 9 BS 3F 65 : 1991 Foreword This British Standard, prepared under the direction of the Aer
3、ospace Standards Policy Committee, is a new edition of BS 2F 65 : 1981, which is withdrawn. This edition introduces technical changes to bring the standard up-to-date, but it does not reflect a full review of the standard, which will be undertaken in due course. Compliance with a British Standard do
4、es not of itself confer immunity from legal obligations. BS 3F 65: 1991 Contents Foreword Page Inside front page Committees responsible Back page Specification 1 2 3 4 5 6 7 8 9 10 11 Scope Construction Materials Dimensions Freedom from defects Freedom from foreign matter Freedom from odour Freedom
5、from internal constriction Vertical load test Marking Approval of rubber mixes 2 2 2 3 3 3 3 3 3 4 4 12 Quality assurance, sampling and packaging 4 Tbles 1 Rubber mix requirements 3 1 Flexible corrugated oxygen tube 2 2 Bore constriction test bob 3 Figures 1 BS 3F 66 : 1991 1 Scope This British Stan
6、dard specifies the requirements for the construction, dimensions, testing and marking of corrugated rubber tubes of 17 mm inteinal diameter, used to deliver oxygen and air at pressures up to 35 kPa to the oxygen-breathing mask, NOTE 1. It does not specify the length or mass of the hose, which will d
7、epend on the purchasers individual requirements, and which should be stated in the contract or order. NIX 2. The latest revision of an Aerospace Series Standard is indicated by a prefix number. The latest edition of the standard should be used. NUIB 3. The titles of the publications referred to in t
8、his standard are listed on the inside back page. 2 Construction 2.1 The tubes shall be seamless and consist entirely of homogeneous rubber compound, corrugated and vulcanized to conoim to the shape shown in figure I. 2.2 All hoses shall comply with BS N 100 in respect of workmanship, material and fi
9、nish. 3 Materials 3.1 The rubber mix from which the tubes are to be manufactured shall be based on high-quality natural or synthetic polyisoprene rubber, and shall be compounded with ingredients such that the finished tubes have no pronounced odour. 3.2 The rubber mix shall be black in coloui; non-b
10、looming and shall comply with the requirements of table 1. 3.3 Before any manufactureis product can be considered for compliance with this standard, the rubber mixes shall have received approval from the Quality Assurance Authority. (See clause 11 for the approval procedure for rubber mixes,) 3.4 Th
11、e rubber mix used for the lining of the hose shall comply with 4.1.4 of BS N 100. + -4.7 2 1.7 Nominal length 1 r - a- A 0:I I IIIIIIIII Sliqht thickenins of end Il All dimensions are in miiiimetres. Figure 1. Flexible corrugated oxygen tube 10.3 2 0.8 - - 2 O a Qble 1. Rubber mix requirements Test
12、Hardness (IRHD) Density (Mg/m3) Tensile strength (ma, min,) Elongation at break (%, min.) Resistance to accelerated ageing (a) Change in tensile strength (% of original value, max.) (b) Change in elongation at break (% of original value, max.) Requirement 66 i 4 Nominal valuel) f 0.02 16 600 - 10 -
13、16 Method BS 903 : Part A26 BS 903 : Part Al method A BS 903 : Part A2 Dumb-bell test pieces BS 903 : Part A19 method A or B, 168 h at 70 OC )The nominal value for density is not critical. It should, howeveq be agreed between the manufacturer and the Quality Assurance Authority, and recorded for the
14、 purpose of ensuring consistency between batches within the tolerances given. 4 Dimensions The dimensions and tolerances of the tubes shall be in accordance with figure 1 and BS 3734, The length of the tubes shall be measured with the tube in a horizontal position and free from stress. 5 Freedom fro
15、m defects 5.1 The tubes shall be free from visible defects such as malformation, pin-holes and inclusions# The internal and external surfaces of the rubber shall be uniformly smooth and the smoothness shall be maintained at the base and apex of each corrugation of the finished tubes. The plain ends
16、shall be cut clearly and square to the longitudinal axis of the tubing. 5.2 If manufactured by moulding, a flash witness is pei-missible on the outside diameter of the tube, but it shall not protrude more than 0.2 mm. 6 Freedom from foreign matter On completion of examination and testing, the interi
17、or of each hose shall be freed from dust, French chalk or other loose particles by blowing through with clean dry air while the hose is being shaken or knocked to dislodge the particles. The hose shalI also be free of other contamination resulting from the use of release agents during manufacture. T
18、he ends of the hose shall then be suitably sealed to prevent contamination. 7 Freedom from odour The tubes shall have no odour other than that of the approved rubber mix described in clauses 3 and 11. 8 Freedom from internal constriction The tube shall allow a brass bob the dimensions shown in figur
19、e 2 to fall readily through it when the tube is suspended vertically. All dimensions are in metres. Figure 2. Bore constriction test bob 9 Vertical load test The tubes shall not fracture when one plain end is held stationary and a mass of 13.6 kg is applied for 10 min to the other plain end. BSI 3F*
20、b5 93 3624669 0239903 7 my - BS 3F 65 : 1991 10 Marking Each tube shall be marked with the following information: (a) the number of this British Standard, i.e, BS 3F 66l); (b) the name or initials of the manufacturer; (c) the quarter and year of manufacture, e.g. 4.91; (d) the batch number. The info
21、rmation shall be marked on a thin white rubber label, firmly adhered near to one end of each tube, clear of the plain end and following the corrugations of the tubes. The marking shall be bold and durable so that the tubes may be readily identified after prolonged service. 11 Approval of rubber mixe
22、s 11.1 Before any manufacturers mixes can be considered for compliance with the requirements of this standard, the rubber mix shall have received approval, l obtain approval the manufacturer shall provide the Quality Assurance Authority with the following: (a) a declaration, in confidence, of the de
23、tailed composition of the mix together with a 1 kg sample of the unvulcanized mix; (b) the proposed conditions of vulcanization (time and temperature) for the two-thickness test sheet prepared from the mix (see 12.2), together with the value for the nominal density for the test sheet (see table 1);
24、(c) a two-thickness test sheet prepared from the mix under the proposed conditions of ll.l(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 certificate of compl
25、iance with 4.1.4 of BS N 100 for the rubber material proposed for the lining of the hose. 11.2 After formal approval has been given, no change in the composition or departure from the agreed proposals of ll.l(b) shall be made without the prior agreement of the Quality Assurance Authority. 12 Quality
26、 assurance, sampling and packaging 12.1 Batch Unless otherwise agreed with the Quality Assurance Authority, a batch of tubes shall consist of all tubes manufactured from one batch of rubber mix and vulcanized under the same conditions. 12.2 Rubber mixes nom each batch of rubber mix, a two-thickness
27、test sheet of the following dimensions shall be prepared and tested in accordance with table 1. The sheet shall be approximately 250 mm2 with a section along one side 35 mm to 50 mm wide and 6.30 f 0.15 mm thick. The remainder of the sheet shall be 2.00 f 0.15 mm thick. The test sheet shall be vulca
28、nized at a temperature appropriate for the mix. No additional vulcanization shall be applied to the thicker section of the sheet in any way whatsoever. NCYE. The frequency of testing to any single requirement may be reduced by agreement between the manufacturer and the Quality Assurance Authority. S
29、uch an agreement should be production of the mix. based on the uniformity of quality and the frequency of 12.3 Tubes 12.3.1 Each tube shall be examined for compliance with the requirements of clauses 4 (excluding wall thickness and radii of corrugations), 5, 6 and 8. 12.3.2 At least one tube from ea
30、ch batch shall be examined for compliance with the requirements of clause 7 and 9. After the test specified in clause 9, the tube shall be cut longitudinally from end to end into several strips, which shall be used for checking the wall thickness and radii of corrugations throughout the length of th
31、e tube. 12.4 Additional testing The Quality Assurance Authority may at any time require test sheets, prepared as described in 12.2 to be tested for compliance with any of the requirements specified in table 1 or samples of the tubes to be tested for compliance with any of the requirements of clauses
32、 4 to 10. 12.6 Packaging and storage Tubes shall be packaged and identified in accordance with BS F 69 and stored in accordance with BS F 68. - i) Marking BS 3F 65 on or in relation to a product represents a manufacturers declaration of conformity, i.e. a claim by or on behalf of the manufacturer th
33、at the product meets the requirements of the standard. The accuracy of the claim is therefore solely the responsibility of the person making the claim. Such a declaration is not to be confused with third party certification of conformity, which may also be desirable. Enquiries as to the availability
34、 of third party certification to suppoi-t such claims should be addressed to the Director, British Standards Institution, Maylands Avenue, Hemel Hempstead, Herts HF2 4SQ in he case of certification marks administered by BSI or to the appropriate authority for other certification marks. 4 BSI 3F*b5 9
35、1 Lb24bb9 0239902 9 S BS 3F 65 : 1991 Publications referred to British Standard F 68 applications British Standard F 69 Specification for controlled storage of vulcanized rubbers for use in aerospace specification for packaging and identification of vulcanized rubber items British Standard N 100 Spe
36、cification for general design requirements for aircraft oxygen systems and equipment BS 903 Physical testing of rubber Part Al Determination of density Part A2 Determination of tensile stress-strain propei3ies Part A19 Heat resistance and accelerated ageing tests Part A26 Determination of hardness S
37、pecification for dimensional tolerances of solid moulded and extruded rubber products BS 3734 e - BSI 3F*b5 91 9 Lb24bb9 0239903 O - e BS 3F 65 : 1991 This British Standard, having been prepared under the direction of the Aerospace Standards Policy Committee, was published under the authority of the
38、 Standards Board and comes into effect on 31 May 1991 O BSI 1991 “he following BSI references relate to the work on this standard: Committee reference ACE/26 Draft for comment 90/76880 DC ISBN O 680 19604 X 9106- 3- 0.7k- B Committees responsible for this British Standard The preparation of this Bri
39、tish Standard was entrusted by the Aerospace Standards Policy Committee (ACE/-) to Technical Committee ACE/25, upon which the following bodies were represented: British Adhesives and Sealants Association British Hydromechanics Research Association British Narrow kbiics Association Biitish Rubber Manufacters Association Ministry of Defence Society of British Aerospace Companies Ltd. Amendments issued since pu dication Amd. No. Date Text affected I I BSI, 2 Park Street, London WlA 2BS BSI, Linford Wood, Miiton Keynes MK14 6LE ACE126
