1、BRITISH STANDARD AEROSPACE SERIES BS2F67:1980 (Superseding BSF67) Specification for Hose for aviation fuel and engine lubricating oil for aeronautical purposes UDC 629.7.065:621.643.3.038BS2F67:1980 This BritishStandard, having been prepared under the directionof the Aerospace Standards Committee, w
2、as published under the authority ofthe Executive Board and comesinto effect on 30September1980 BSI 02-2000 The following BSI references relate to the work on this standard: Committee reference ACE/25 Draft for comment 79/77610 DC ISBN 0 580 11565 8 Foreword This BritishStandard was first published i
3、n1966 as a replacement for the then Ministry of Aviation DTD625A. This revision updates the requirements and introduces metric units. The metrication of the internal diameters of the hose has been based on the original imperial dimensions to avoid unnecessary changes in manufacturing equipment. BSF6
4、7 specified that the hose was suitable for use in lengths not exceeding18inches. This requirement is now thought to be unrealistic, and has been omitted from the revision. It should be recognized, however, that the hose is intended to be used in short lengths as couplings between rigid metal pipes.
5、The purchaser is required to specify the individual lengths of type2 hose required, to enable the ends to be finished without the embedded wire helix. A British Standard does not purport to include all the necessary provisions of a contract. Users of British Standards are responsible for their corre
6、ct 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 to6 and a back cover. This standard has been updated (see copyright date) and may have had
7、 amendments incorporated. This will be indicated in the amendment table on the inside front cover. Amendments issued since publication Amd. No. Date of issue CommentsBS2F67:1980 BSI 02-2000 i Contents Page Foreword Inside front cover 1 Scope 1 2 References 1 3 Construction 1 4 Materials 2 5 Dimensio
8、ns 2 6 Freedom from defects 2 7 Tests on finished hose 2 8 Marking 2 9 Routine inspection and sampling 3 Table 1 Bead height 1 Table 2 Rubber requirements 4 Table 3 Dimensions and physical properties of types1 and2 hose 5 Table 4 Dimensions and physical properties of type3 hose 6ii blankBS2F67:1980
9、BSI 02-2000 1 1 Scope This BritishStandard specifies the requirements for the construction, dimensions, testing and marking of the following three types of hose used for coupling rigid metal pipes, carrying aviation fuel or engine oil of either mineral or synthetic di-ester type, in aircraft. Type1.
10、 Woven fabric reinforced hose. Type2. Woven fabric reinforced hose with embedded wire helix. Type3. Braided textile reinforced hose. The hose is suitable for use at continuous working temperatures from40 C up to100 C and at maximum working pressures of a quarter of the specified minimum bursting pre
11、ssure. At higher temperatures the service life would be progressively shortened. 2 References This standard makes reference to the following standards publications. BS381C, Colours for specific purposes. BS903, Methods of testing vulcanized rubber Part A1: Determination of density PartA2:Determinati
12、on 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 test) Part A16: The resistance of vulcanized rubber to liquids PartA19: Heat resistance and accelerated ai
13、r ageing tests Part A26: Determination of hardness. BS3592, Steel wire for rubber hose reinforcement Part 1: Coated round and flat mild steel wire. BS5173, Methods of test for hoses Part1:Measurement of dimensions Part2:Hydraulic pressure tests Part3: General physical tests. 3 Construction 3.1 Type1
14、 3.1.1 Type1 hose shall be made of a lining of rubber, covered with a number of fabric plies which in turn shall be covered with an outer layer of rubber. The hose shall be mandrel built, consolidated by wrapping and uniformly vulcanized. 3.1.2 The rubber lining shall be seamless in all hose having
15、an internal diameter of50mm or less. It may be made from rubber sheet in the case of larger hose and, if so made, shall be formed of at least two whole turns of the sheet. The minimum thickness of the lining shall be in accordance withTable 3, column (iii). 3.1.3 The fabric shall be cut on the bias.
16、 The number of plies shall be in accordance withTable 3, column(vii). The fabric shall be longitudinally wrapped. All overlaps shall be not less than7mm. 3.1.4 The fabric shall be coated with a suitable oil-resisting synthetic rubber so that the plies of fabric adhere firmly to each other and to the
17、 rubber lining and cover and are separated from each other by a thin layer of rubber. 3.1.5 The cover shall be of sufficient thickness to bury the overlap. 3.2 Type2 3.2.1 Type2 hose shall be constructed like type1 hose as specified in3.1, but with the addition of a helix of wire embedded in the wal
18、l between two plies of fabric in accordance withTable 3, column (viii). 3.2.2 The hose shall show externally the natural corrugations caused by the embedded wire. 3.2.3 The hose shall be supplied in lengths as specified in the contract or order and each length shall have75mm at each end free of wire
19、. 3.3 Type3 3.3.1 Type3 hose shall be similar to type1 hose, except that the reinforcement shall consist of two plies of textile braid. 3.3.2 The angle of braiding and hardness of the rubber shall be such that the hose can, without undue force, be fitted on to a pipe whose external diameter is the s
20、ame as that of the nominal bore of the hose and with a beaded end, the height of the bead being as specified inTable 1. Table 1 Bead height The hose shall fit snugly on to the pipe at a distance of not more than25mm from the bead. 3.3.3 The plies of braid shall be separated from oneanother by an ins
21、ulating layer of a suitable oil-resisting synthetic rubber and shall be so impregnated with the rubber that they give the adhesion strength required. 3.3.4 The cover shall be of the minimum thickness necessary to cover the braid. Nominal internal diameter Bead height mm Up to and including25 Over25
22、up to and including75 Over75 mm 0.8 1.6 2.5BS2F67:1980 2 BSI 02-2000 4 Materials The following materials shall be used in the construction of all types of hose. 4.1 Rubber mix 4.1.1 Lining. The rubber mix used for the lining shall be based on a butadiene-acrylonitrile copolymer and shall comply with
23、 the relevant requirements ofTable 2. 4.1.2 Cover. The rubber mix used for the cover shall be based on a chloroprene polymer. It shall be ozone resistant, black in colour and shall comply with the relevant requirements ofTable 2. 4.2 Fabric. The fabric reinforcement used in types1 and2 hose shall be
24、 cotton duck weighing not less than240g/m 2 , or an equivalent viscose fabric. 4.3 Wire. The wire used in type2 hose shall be steel wire in accordance with BS3592-1, of the gauge and number of turns per metre run of hose specified inTable 3, columns (ix) and (x). 4.4 Braided reinforcement. The braid
25、ed reinforcement used in type3 hose shall be textile cord. 5 Dimensions The dimensions and tolerances shall be in accordance withTable 3 orTable 4, columns (i) to(vi). The wall thickness shall be measured at a part of the hose that is free from overlap and, in the case of type2 hose, at the ends whe
26、re the wall is free from wire. NOTESuitable methods for measuring wall and lining thickness are given in BS5173-1. 6 Freedom from defects 6.1 The hose shall be of substantially circular section and the rubber lining and cover shall be uniform, reasonably concentric and free from holes, porosity and
27、other visible defects likely to affect its service life or utility. 6.2 The outer surfaces may have a cloth-mark finish such as that resulting from the imprint of closely woven fabric of not less than16 ends and16 picks per centimetre. Occasional shallow surface defects produced by weaving faults in
28、 the fabrics used for external wrapping during manufacture shall not be regarded as a cause for rejection. 7 Tests on finished hose 7.1 Resistance to ply separation. The resistance of the hose to ply separation shall be determined by the method described in BS5173-3. Two adjacent test pieces shall b
29、e taken for each test, and the starting point for the test in the second test piece shall be at180 to that in the first. The adhesion strength shall be not less than 1.8N/mm width for the cover/fabric interface 1.8N/mm width for the lining/fabric interface 2.2N/mm width for the fabric/fabric interfa
30、ce If there are visible areas of poor adhesion in a test piece, their combined area shall not exceed15% of the stripped area of the test piece, with no single area exceeding10% of the stripped area. 7.2 Resistance to hydraulic pressure. The hose shall be hydrostatically tested by the method for gene
31、ral industrial rubber hoses described in BS5173-2 except that the minimum rate of pressure increase shall be1.75 bar/s 1)and the maximum3.5bar/s. 7.2.1 The bursting pressure shall be not less than the value given inTable 3, column xi, orTable 4, column vii. 7.2.2 For type3 hose only, the increase in
32、 the external diameter, at a pressure equal to one-third of the minimum bursting pressure, shall be not more than the value given inTable 4, columnviii. 8 Marking Each length of hose shall be marked with the following information: a) the number of this BritishStandard, i.e.BS2F67 2) ; b) the type (e
33、.g.3); c) nominal internal diameter, in mm; d) the manufacturers identity; e) the quarter and year of manufacture (e.g.1/81). The information shall be marked by print, vulcanized label or moulded imprint on the surface of the hose at one end of lengths up to2m, and at each end of lengths over2m. The
34、 print, vulcanized labels or moulded imprint shall be resistant to aviation fuels and engine oil of either mineral or synthetic di-ester type. 1) 1bar=10 5 N/m 2 =100kPa. 2) Marking BS2F67 on or in relation to a product is a claim by the manufacturer that the product has been manufactured in accorda
35、nce with the requirements of the standard. The accuracy of such a claim is therefore the manufacturers sole 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 H
36、empstead, Herts HP24SQ in the case of certification marks administered by BSI or to the appropriate authority for other certification marks.BS2F67:1980 BSI 02-2000 3 Additionally, a longitudinal straight colour-fast blue line (approximately to109 middle blue BS381C) of between3mm and6mm width shall
37、be marked along the entire length of the hose. 9 Routine inspection and sampling 9.1 Batch. Unless otherwise agreed with the Quality Assurance Authority, a batch of hose shall consist of all lengths of one size produced from a uniform batch of each rubber mix and vulcanized under the same conditions
38、. 9.2 Rubber mixes. From each batch of rubber mix, a two-thickness test sheet of the following dimensions shall be prepared and tested to the requirements ofTable 2. NOTEThe frequency of testing to any single requirement may be reduced by agreement between the manufacturer and the quality assurance
39、authority. Such an agreement should be based on the uniformity of quality and the frequency of production of the material. 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 thick. If desired
40、, part of the6.3mm section may be moulded in the form of cylindrical buttons conforming to the requirements of the type1 test piece as defined in BS903-A6 for the purpose of compression set tests. When such buttons are moulded, the cavities shall be individually charged with pellets and not by the f
41、low 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 for a time and at a temperature appropriate for the mix. No additional vulcanization shall be
42、 applied to the thicker section (or buttons) of the sheet in any way whatsoever. 9.3 Hoses 9.3.1 Each length of hose supplied shall be examined for compliance with the requirements of clauses3, 5 and6. 9.3.2 At least one piece of hose of types1 and3, approximately1.5m long, from each batch shall be
43、tested for compliance with the requirements of7.1 and7.2. 9.3.3 At least two lengths of type2 hose, as ordered, from each batch shall be tested for compliance with the requirements of7.1 and7.2. 9.4 Additional testing. The quality assurance authority may, at any time, require test sheets, prepared,
44、as described in9.2, to be tested for compliance with any of the requirements specified inTable 2, or samples of hose to be tested for compliance with any of the requirements of clauses3, 5, 6 and7.BS2F67:1980 4 BSI 02-2000 Table 2 Rubber requirements Test Requirement Method Lining Cover i) Hardness,
45、 IRHD ii) Density, Mg/m 3 Nominal value a 4 Nominal value a 0.02 Nominal value a 4 Nominal value a 0.02 BS903-A26, method N BS903-A1, method A iii) Tensile strength, MPa, minimum iv) Elongation at break,%, minimum 8.5 150 10.5 200 BS903-A2, dumbbell test pieces v) Resistance to accelerated ageing: a
46、) Change in hardness, IRHD, maximum b) Change in tensile strength, percentage of original value, maximum c) Change in elongation at break, percentage of original value, maximum +5 2 10 +5 25 +8 2 15 +5 25 BS903-A19, method A or B,168h at70 C vi) Compression set,%, maximum vii) Resistance to low temp
47、erature: stiffness at 20 C, MPa, maximum 30 70 35 70 BS903-A6, type1 test pieces, 24h at70 C (lubricated) BS903-A13 viii) Volume change,%, after immersion in: liquid A liquid B +10 2 +30 0 +75 0 BS903-A16, volumetric method. Immersion for96h at40 C liquid101 +20 0 BS903-A16, volumetric method. Immer
48、sion for96h at120 C a The nominal values for hardness and density are not critical. They should, however, be agreed between the manufacturer and the quality assurance authority, and recorded for the purpose of ensuring consistency between batches within the tolerances given. BS2F67:1980 BSI 02-2000
49、5 Table 3 Dimensions and physical properties of types1 and2 hose Internal diameter Minimum lining thickness Nominal external diameter Wall thickness No. of fabric plies Embedded wire (type2 only) Minimum burst pressure Nominal Tolerance min. max. Position a Diameter No. of turns per metre Nominal Tolerance mm (i) 4.8 b 6.3 b 8.0 b 9.5 b 11.0 b 12.7 b 15.9 19.0 22.2 25.4 28.6 30.2 31.8 35.0 38.1 41.3 mm (ii) 0.4 0.4 0.4 0.4 0.4 0.4 0.4 0.8 0.8 0.8 0.8 0.8 0.8 0.8 0.8 0.8
