1、BRITISH STANDARD BS ISO 8829-2:2006 Aerospace Test methods for polytetrafluoro- ethylene (PTFE) inner-tube hose assemblies Part 2: Non-metallic braid ICS 49.080; 83.140.40 BS ISO 8829-2:2006 This British Standard was published under the authority of the Standards Policy and Strategy Committee on 31
2、October 2006 BSI 2006 ISBN 0 580 49346 6 National foreword This British Standard was published by BSI. It is the UK implementation of ISO 8829-2:2006. The UK participation in its preparation was entrusted to Technical Committee ACE/69, Aerospace hydraulic systems, fluids and components. A list of or
3、ganizations represented on ACE/69 can be obtained on request to its secretary. This publication does not purport to include all the necessary provisions of a contract. Users are responsible for its correct application. Compliance with a British Standard cannot confer immunity from legal obligations.
4、 Amendments issued since publication Amd. No. Date Comments Reference number ISO 8829-2:2006(E)INTERNATIONAL STANDARD ISO 8829-2 First edition 2006-09-15 Aerospace Test methods for polytetrafluoroethylene (PTFE) inner-tube hose assemblies Part 2: Non-metallic braid Aronautique et espace Mthodes dess
5、ai des tuyauteries flexibles tube intrieur en polyttrafluorothylne (PTFE) Partie 2: Tuyauteries gaine non mtallique BS ISO 8829-2:2006ii iii Contents Page Foreword iv Introduction v 1 Scope . 1 2 Normative references . 1 3 Terms and definitions. 2 4 Test temperature. 2 5 Tests on PTFE inner tubes 2
6、5.1 Density and relative density 2 5.2 Tensile tests 2 5.3 Rolling and proof-pressure tests 4 5.4 Electrical conductivity test 6 6 Test on hoses and hose assemblies 6 6.1 Stress degradation test 6 6.2 Pneumatic effusion test . 8 6.3 Electrical conductivity test 9 6.4 Visual and dimensional inspectio
7、n. 10 6.5 Determination of elongation or contraction. 10 6.6 Volumetric expansion test . 10 6.7 Leakage test 12 6.8 Proof-pressure test. 12 6.9 Burst-pressure tests. 12 6.10 Impulse test . 13 6.11 Flexure test 13 6.12 Fuel resistance test 15 6.13 Low-temperature flexure testing . 15 6.14 Pneumatic l
8、eakage test 15 6.15 Vacuum test. 15 6.16 Pneumatic surge test 16 6.17 Thermal shock test . 16 6.18 Light-radiation aging 17 6.19 Push-pull test 18 6.20 Fire test 19 Annex A (informative) Test fluids . 20 Bibliography . 21 BS ISO 8829-2:2006iv Foreword ISO (the International Organization for Standard
9、ization) is a worldwide federation of national standards bodies (ISO member bodies). The work of preparing International Standards is normally carried out through ISO technical committees. Each member body interested in a subject for which a technical committee has been established has the right to
10、be represented on that committee. International organizations, governmental and non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization. International Stand
11、ards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2. The main task of technical committees is to prepare International Standards. Draft International Standards adopted by the technical committees are circulated to the member bodies for voting. Publication as an Inte
12、rnational Standard requires approval by at least 75 % of the member bodies casting a vote. Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. ISO shall not be held responsible for identifying any or all such patent rights. ISO 8829-2
13、 was prepared by Technical Committee ISO/TC 20, Aircraft and space vehicles, Subcommittee SC 10, Aerospace fluid systems and components. ISO 8829-2 cancels and replaces ISO 8829:1990, which has been technically revised. ISO 8829 consists of the following parts, under the general title Aerospace Test
14、 methods for polytetra- fluoroethylene (PTFE) inner-tube hose assemblies: Part 1: Metallic (stainless steel) braid Part 2: Non-metallic braid BS ISO 8829-2:2006v Introduction This part of ISO 8829 is intended to standardize the test methods for qualification of polytetrafluoroethylene (PTFE) hose an
15、d hose assemblies used in aircraft fluid systems. The tests are intended to simulate the most strenuous demands encountered in aircraft. Compliance with these test methods is necessary for hose and hose assemblies which are used in systems where a malfunction could affect the safety of flight. BS IS
16、O 8829-2:2006blank1 Aerospace Test methods for polytetrafluoroethylene (PTFE) inner-tube hose assemblies Part 2: Non-metallic braid 1 Scope This part of ISO 8829 specifies test methods for flexible polytetrafluoroethylene (PTFE) inner tubes with non-metallic braided hose and hose assemblies used in
17、aircraft fluid systems, in the pressure and temperature ranges covered by pressure classes and temperature types, as specified in ISO 6771. This part of ISO 8829 applies to the hose and the hose coupling. The tests and assembly requirements for the connecting end fittings are covered in the procurem
18、ent specification. This part of ISO 8829 is applicable when reference is made to it in a procurement specification or other definition document. NOTE Fluids used for the tests are listed in Annex A. 2 Normative references The following referenced documents are indispensable for the application of th
19、is document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. ISO 2685:1998, Aircraft Environmental test procedure for airborne equipment Resistance to fire in designated fire zones ISO 677
20、1 1) , Aerospace Fluid systems and components Pressure and temperature classifications ISO 6772:1988, Aerospace Fluid systems Impulse testing of hydraulic hose, tubing and fitting assemblies ISO 6773:1994, Aerospace Fluid systems Thermal shock testing of piping and fittings ISO 7258:1984, Polytetraf
21、luoroethylene (PTFE) tubing for aerospace applications Methods for the determination of the density and relative density 1) To be published. (Revision of ISO 6771:1987) BS ISO 8829-2:20062 3 Terms and definitions For the purposes of this document, the following terms and definitions apply. 3.1 fire
22、sleeve flame- and heat-retardant element, normally tubular, slipped over the hose assembly and fastened to the hose fitting 3.2 fire-cover flame- and fire-retardant element, normally (silicone) rubber, moulded over the hose and hose fittings 4 Test temperature Unless otherwise specified, tests shall
23、 be conducted between 15 C and 32 C (59 F and 90 F). 5 Tests on PTFE inner tubes 5.1 Density and relative density 5.1.1 Principle The test is intended to control the crystallinity of PTFE inner tubes. 5.1.2 Test methods The relative density of the PTFE tubing shall be measured in accordance with ISO
24、 7258:1984, method A or method B. The density of the PTFE tubing shall be measured in accordance with ISO 7258:1984, method C. 5.2 Tensile tests 5.2.1 Principle This test is intended to determine the mechanical properties of the PTFE tubing. 5.2.2 Test conditions Test specimens shall be conditioned
25、for at least 2 h at room temperature prior to testing. 5.2.3 Apparatus 5.2.3.1 Testing machine The test shall be carried out using a power-driven machine which is capable of maintaining a uniform rate of jaw separation at 50 mm/min (2 in/min) and which has a suitable dynamometer and a device for mea
26、suring the force applied within 2 %. If the capacity range cannot be changed during a test, as in the case of pendulum dynamometers, the force applied at breaking point shall be measured within 2 %, and the smallest tensile force measured shall be accurate to within 10 %. If the dynamometer is of th
27、e compensating type for measuring tensile stress directly, means shall be provided to make adjustments for the cross- sectional area of the test specimen. The response of the recorder shall be sufficiently rapid for the force applied to be measured accurately during the elongation of the test specim
28、en to breaking point. If the test machine is not equipped with a recorder, a device shall be provided that indicates, after fracture, the maximum force applied during elongation. Testing machines shall be capable of measuring elongation in increments of 10 %. BS ISO 8829-2:20063 5.2.3.2 Micrometer T
29、he micrometer used for measuring flat test specimen thickness shall be capable of exerting a pressure of 25 kPa 5 kPa (3,63 psi 0,7 psi) on the test specimens, and of measuring the thickness to within 0,025 mm (0,001 in). Dial micrometers exerting either a force of 0,8 0,15 N (0,18 lbf 0,034 lbf) on
30、 a circular foot 6,35 mm (0,25 in) in diameter or a force of 0,2 0,04 N (0,045 lbf 0,009 lbf) on a circular foot 3,2 mm (0,125 in) in diameter conform to the pressure requirement specified above. A micrometer should not be used to measure the thickness of test specimens narrower in width than the di
31、ameter of the foot, unless the contact pressure is properly adjusted. 5.2.4 Calibration of testing machine The testing machine shall be calibrated. If the dynamometer is of the strain-gauge type, the test machine shall be calibrated at one or more forces at regular intervals. 5.2.5 Test specimens Th
32、e specimens shall be in accordance with Figure 1. NOTE Careful maintenance of the cutting edges of the die is extremely important and can be achieved by light daily honing and touching up of the cutting edges with jewelers hard honing stones. The condition of the die may be assessed by determining t
33、he breaking point on any series of broken test specimens. When broken test specimens are removed from the jaws of the test machine, it is advantageous to pile these test specimens and note if there is any tendency to break at or near the same portion of each test specimen. Breaking points consistent
34、ly occurring at the same place may be an indication that the die is dull, nicked or bent at that particular position. Dimensions in millimetres Figure 1 Test specimen for tensile test 5.2.6 Determination of tensile strength and elongation 5.2.6.1 Procedure Place the test specimens (see 5.2.5) in the
35、 jaws of the testing machine (5.2.3.1), taking care to adjust the specimen symmetrically so that the tension will be distributed uniformly over the cross-section. Start the machine and note continuously the distance between the jaws, taking care to avoid parallax. At fracture, measure and record the
36、 elongation to the nearest 10 % on the scale. BS ISO 8829-2:20064 5.2.6.2 Expression of results Calculate the tensile strength, R m , in newtons per square millimetre 2) , using the following equation: m F R S = where F is the measured force, in newtons, required to fracture the test specimens; S is
37、 the cross-sectional area, in square millimetres, of the test specimen before application of force. Calculate the percentage total elongation at fracture, A t , using the following equation: uo t o 100 LL A L = where L uis the length measured between the jaws at fracture of the test specimen; L ois
38、the original length measured between the jaws before application of force. 5.3 Rolling and proof-pressure tests 5.3.1 Principle This test is intended to check that there are no flaws in the sintered tube. 5.3.2 Rolling test Procedure Pass each tube, in a single pass, through six sets of metal roller
39、s so that it is subjected to the sequence of diametral flexings specified in Table 1; rollers shall be arranged to prevent inadvertent rotation in the tube. It is assumed that the tube is in a horizontal position and that pressure of the first set of rollers is exerted vertically; angles given for t
40、he final three sets of rollers may be taken as either clockwise or counterclockwise from the vertical diameter of the tube. Roller angles shall be as specified in Table 1. A tolerance of 2 is allowed on each roller angle. The roller gap dimensions shall not be larger than those specified in Table 2
41、for each size. Table 1 Roller functions and angles Set of metal rollers Type of action Roller angle 1 Flattening 0 2 Flattening 90 3 Rounding 0 4 Flattening 45 5 Flattening 135 6 Rounding 45 2) 1 N/mm 2= 1 MPa BS ISO 8829-2:20065 Table 2 Roller gap dimensions 3)Hose size Flattening gap max. Rounding
42、 gap max. Metric part Inch part Equivalent outside diameter of tube Class B 10 500 kPa (1 523 psi) and lower nominal pressure Class D 21 000 kPa (3 046 psi) and higher nominal pressure Class B 10 500 kPa (1 523 psi) and lower nominal pressure Class D 21 000 kPa (3 046 psi) and higher nominal pressur
43、e Size Size mm (in) mm (in) mm (in) mm (in) mm (in) DN05 03 4,762 (0,187) 5,2 (0,203) 5,2 (0,203) 5,5 (0,218) 6,4 (0,250) DN06 04 6,350 (0,250) 5,5 (0,218) 7,1 (0,281) 5,5 (0,218) 6,4 (0,250) DN08 05 7,937 (0,312) 5,5 (0,218) 6,4 (0,250) DN10 06 9,525 (0,375) 5,5 (0,218) 7,1 (0,281) 7,9 (0,312) 8,3
44、(0,328) DN12 08 12,700 (0,500) 5,9 (0,234) 8,3 (0,328) 9,5 (0,375) 11,9 (0,469) DN16 10 15,875 (0,625) 6,4 (0,250) 8,3 (0,328) 12,7 (0,500) 14,7 (0,578) DN20 12 19,050 (0,750) 6,4 (0,250) 8,3 (0,328) 12,7 (0,500) 17,5 (0,688) DN25 16 25,400 (1,000) 6,4 (0,250) 8,3 (0,328) 19,1 (0,750) 21,0 (0,828) D
45、N32 20 31,750 (1,250) 7,9 (0,312) 11,1 (0,438) 22,2 (0,875) 25,4 (1,000) DN40 24 38,100 (1,500) 9,5 (0,375) 31,8 (1,250) 5.3.3 Proof-pressure test Procedure After the roll test, hold the tube for not less than 2 min. at proof pressures as shown in Table 3, using water or air as the test medium. Tabl
46、e 3 Proof pressure 3)Hose size Proof pressure Metric part Inch part Equivalent outside diameter of tube Class B 10 500 kPa (1 523 psi) and lower nominal pressure Class D 21 000 kPa (3 046 psi) and higher nominal pressure Nominal pressure 10 342 kPa (1 500 psi) and lower nominal pressure Nominal pres
47、sure 20 684 kPa (3 000 psi) and higher nominal pressure Size Size mm (in) kPa (psi) kPa (psi) kPa (psi) kPa (psi) DN05 03 4,762 (0,187) 2 690 (390) 3 310 (480) 2 690 (390) 3 310 (480) DN06 04 6,350 (0,250) 2 480 (360) 2 620 (380) 2 480 (360) 2 620 (380) DN08 05 7,937 (0,312) 2 000 (290) 2 000 (290)
48、DN10 06 9,525 (0,375) 1 590 (230) 1 930 (280) 1 590 (230) 1 930 (280) DN12 08 12,700 (0,500) 1 240 (180) 1 520 (220) 1 240 (180) 1 520 (220) DN16 10 15,875 (0,625) 1 170 (170) 1 170 (170) 1 170 (170) 1 170 (170) DN20 12 19,050 (0,750) 965 (140) 890 (130) 965 (140) 890 (130) DN25 16 25,400 (1,000) 62
49、1 (90) 660 (95) 621 (90) 660 (95) DN32 20 31,750 (1,250) 448 65) 660 (95) 448 (65) 660 (95) DN40 24 38,100 (1,500) 310 (45) 310 (45) 3) Special size high pressure hose assembly callout shall utilize lower hose size value noted. BS ISO 8829-2:20066 5.4 Electrical conductivity test 5.4.1 Preconditioning The test specimen sha
