1、DEUTSCHE NORM Februarv 1996 I Polyamide tubing for air braking systems I DIN - Part 1 : Requirements and testing I 74324-1 ICs 23.040.20; 43.040.40 Descriptors: Road vehicles, braking systems, tubing, polyamide. Supersedes October 1991 edition Druckluftbremsanlagen - Rohre und Rohrleitungen aus Poly
2、amid - Teil 1 : Anforderungen und Prfungen In keeping with current pratice in standards published by the International Organization for Standardization (ISO), a comma has been used throughout as the decimal marker. Foreword This standard has been prepared by the Normenausschu Kraftfahrzeuge (Road Ve
3、hicles Standards Com- mittee), Technical Committee Polyamidrohre. Amendments In comparison with the October 1991 edition, specifications for types PA 12-HIPHL, PA 11-PHLY and PA 12-PHLY moulding materials have been introduced (cf. tables 2 and 6). Previous editions References to DIN 73378 are to the
4、 February 1996 edition. DIN 74324-1 : 1978-08, 1987-07, 1991 -1 O. Dimensions in mm 1 Scope and field of application This standard specifies requirements and methods of test for single-ply tubing of polyamide (as in DIN 73378) for use in the air braking systems of road vehicles and trailers (cf. def
5、initions in DIN 7001 O). The polyamide materials covered by this standard (cf. clause 6) are resistant to ageing under normal service conditions (i.e. the working pressures and temperatures specified in tables 2 and 3), and, when not under pressure, for three hours at 125 “C. This standard does not
6、apply to tubing connecting trailers to the tow vehicle. The mounting of tubing on vehicles is dealt with in DIN 74324-2. Continued on pages 2 to 6. Translation by DI N-Sprachendienst In case of doubt, the German-language original should be consulted as the authoritative text No pari of this translat
7、ion may be reproduced without the prior permission of Ref. No. DIN 74324-1 : 1996-0 V Deutsches Institut fr Nonung e. V., Berlin. Luth Verlag GmbH, D-10772 Berlin, has the exclusive right of sale for German Standards (DIN-Normen). English price group 07 Sales No. 0107 04.98 Page 2 DIN 74324-1 : 1996
8、-02 2 Normative references This standard incorporates, by dated or undated reference, provisions from other publications. These normative references are cited at the appropriate places in the text and the titles of the publications are listed below. For dated references, subsequent amendments to or
9、revisions of any of these publica- tions apply to this standard only when incorporated in it by amendment or revision. For undated refer- ences, the latest edition of the publication referred to applies. DIN 3861 DIN 58383 DIN 7001 O DIN 73377 DIN 73378 DIN 74324-2 IS0 2768-1 : 1989 Olives for use w
10、ith compression couplings - Design and type W ports Magnifiers - Types and optical characteristics Classification of road vehicles - Terminology associated with passenger cars, commercial vehicles and trailers Fittings for polyamide tubing - Insert profiles Polyamide tubing for use in motor vehicles
11、 Polyamide tubing for air braking systems - Guide for assembly General tolerances - Part 1 : Tol- erances for linear and angular dimensions without individual tolerance indications 3 Concepts 3.1 Tubing without fittings: For the purposes of this standard, tubing without end fittings has an un- speci
12、fied length (cf. clause 4). 3.2 Tubing with fittings: For the purposes of this standard, tubing with end fittings has a specified length (cf. clause 5). 4 Tubing without fittings 4.1 Dimensions and designation Designation of tubing of nominal size 8 x 1 made from polyamide moulding material type PA
13、11 -P, EHL, 22-004 (PA 11 -PHL): Tubing DIN 74324 - 8 x 1 - PA 11-PHL 4.2 Requirements 4.2.1 General 4.2.1.1 Density See table 7 of DIN 73378. 4.2.1.2 Melting temperature See table 7 of DIN 73378. 4.2.1.3 Extractable matter See subclause 5.2.5 of DIN 73378. 4.2.1.4 Workmanship See subclause 5.3 of D
14、IN 73378. 4.2.1.5 Stress utilization factor See table 6 of DIN 73378. 4.2.1.6 Basic stress See subclause 5.4.3 of DIN 73378. 4.2.1.7 Impact strength See subclause 5.4.4 of DIN 73378. 4.2.1.8 Allowable working pressure See tables 2 and 3 of the present standard. 4.2.1.9 Materials The tubing shall be
15、extruded from 1 O0 YO virgin ma- terial (not regrind). The use of recycled material is not permitted, but reworked material may be used as grinding stock, as long as it does not make up more than 20 YO of the new material, is of the same material type and is from the manufacturers own production, an
16、d the tubing meets all other requirements of this standard. 4.2.2 Other requirements 4.2.2.1 Resistance to UV radiation When tested as specified in subclause 4.4.2.1, the specimens shall show no signs of cracking when examined under X6 magnification. In addition, the requirements for impact energy a
17、t (23 k 2) “C specified in table 7 of DIN 73378 shall be met. Figure 1: Tubing dimensions (rotation) 15x1,5 16x2 18 x2 Table 2: Allowable working pressures at 23 “C for tubing designed for a working temperature range of -40 to +lo0 “C f0,15 15 12 f 0,l 1,35 X X 90 16 12 X X 95 18 14 X - 1 O0 f0,15 1
18、,80 Nominal size 4x1 6x1 I 27 I 36 Allowable working pressure, for moulding material of type Pe, zul in bar -PHL PA12-PHL PA1 1 -PHLY PA12-HIPHL PA12-PHLY 45 60 10x1 1Ox1,25 I 19 I 26 15 11 x1,5 I 21 I 28 18x2 12x13 I 19 I 26 17 8x1 9x 1,5 Table 3: Allowable working pressures at 23 “C for tubing des
19、igned for a working temperature range of -40 to +60 “C I 19 26 27 36 Allowable working pressure, Nominal size Pe, zul in bar 14x2 16x2 22 30 19 26 I 15x1,5 I 15 4.2.2.2 Thermal stability The specimens subjected to testing as in subclause 4.4.2.2 a) shall show no signs of cracking when ex- amined und
20、er X6 magnification. The specimens subjected to basic stress testing as in subclause 4.4.2.2 b) shall comply with the mini- mum basic stress requirements given in subclause 5.4.3 and table 7 of DIN 73378. The specimens subjected to impact testing as in subclause 4.4.2.2 c) shall comply with the impa
21、ct energy values for a temperature of (23 k 2) “C speci- fied in table 7 of DIN 73378. Page 4 DIN 74324-1 : 1996-02 Melting temperature Extractable matter 4.2.2.3 Density When tested as specified in subclause 4.4.2.3, tub- ing shall remain leaktight and no other failure shall occur. 6.4.2 6.4.4 4.3
22、Test classes Tubing is to be subjected to type testing (test classA) and/or to in-process testing as part of the quality control procedures (test class B), as specified in table 4. Table 4: Test classes Basic stress Impact energy Property (Requirement) I Tyt c/asses B 6.4.5 6.4.6 I - Density (cf. ta
23、ble 7 of DIN 73378) I - Melting temperature (cf. table 7 of DIN 73378) Extractable matter (cf. subclause 5.2.5 of DIN 73378) Workmanship (cf. subclause 5.3 of DIN 73378) Basic stress (cf. subclause 5.4.3 of DIN 73378) Impact strength (cf. subclause 5.4.4 of DIN 73378) I XI - Resistance to UV radiati
24、on (cf. subclause 4.2.2.1) I - Thermal stability I) (cf. subclause 4.2.2.2) I) Applies only to thermally stabilized moulding materials. t 3 E C a, .- L 2 Q C (u U (u K + .- 4.4 Testing 4.4.1 Testing to DIN 73378 Table 5: Testing Testing as in DIN 73378, subclause Property Density I 6.4.1 Workmanship
25、 I I) I) To be checked visually at a normal viewing dis- tance (e.g. as in DIN 58383). 1.4.2 Other tests 4.4.2.1 Resistance to UV radiation First, expose five 1 O0 mm sections of tubing of each nominal size for a period of 720 hours to radiation in the medium- and long-wave UV ranges (UV-A and UV-B
26、in figure 2). Place the specimens on a turntable with a diameter of 430 mm and a rotating speed of (33 k 3) min- in a radial arrangement so that one end of each specimen touches the edge of the turntable and the other end points towards the centre. Secure both ends of each specimens. Position the ra
27、diation source above the turntable centre and at a distance of (250 k 5) mm. Cool speci- mens, if necessary, so that the temperature of the specimens does not exceed 50 “C. Use a new radia- tion source for each test. 2851 380 600 ts 1000 1400 nm 2000 315 Wavelength, h Figure 2: Spectral distribution
28、 Page 5 DIN 74324-1 : 1996-02 I I I I Then, subject the specimens to impact testing as in DIN 73378, but only at a test temperature of (23 k 2) “C. Place the specimens in a pendulum impact testing machine in such a manner that the irradiated side is not subjected to impact. If the specimens have to
29、be shortened (to fit into the testing machine), they are to be cut equally at both ends so that the centre of the specimens which has been irradiated remains. In any case, the specimens shall be at least 50 mm long. PA1 1 -PHL PA12-PHL PA12-HIPHL 4.4.2.2 Thermal stability Condition nine specimens of
30、 each nominal size in a forced-circulation oven at 150 “C for 72 hours. a) Prior to placing the specimens in the oven, take three specimens of each nominal size and bend them to 180“ according to the values for minimum bending radii given in table 1. After con- ditioning, remove the specimens, strai
31、ghten them and examine them for cracking. b) Thirty minutes after the specimens have been removed from the oven, subject three specimens of each nominal size to basic stress testing as in DIN 73378. c) Thirty minutes after the specimens have been removed from the oven, subject three specimens of eac
32、h nominal size to an impact test at (23 k 2) “C as in DIN 73378. PA1 1 -PHLY PA12-PHLY 4.4.2.3 Density Subject three specimens of each nominal size to the test pressures given in table 6 for three minutes at 23 “C. Table 6: Test pressures at 23 “C 10x1 10 x 1,25 Nominal size 22 - 28 39 12 x 1,5 14x2
33、 28 39 33 45 4x1 I 68 I 90 I 6x1 I 40 I 54 I 8x1 I 28 I 39 I 9x1,5 I 40 I 54 I 11 x1,5 I 32 I 42 I 15x1,5 I 22 I - I 16x2 I 28 I 39 I 18x2 I 25 I - I 5 Tubing with fittings 5.1 Dimensions and designation For general tolerances, tolerance class c as specified in IS0 2768 shall apply. For dimensions,
34、see table 1. End fittings as specified by the road vehicle manufacturer 7 Figure 3: Tubing with fittings Designation of tubing with fittings of nominal size 8 x 1, with a length between fittings, 2, of 500 mml), made of polyamide moulding material of type Tubing DIN 74324 - 8 x 1 x 500 - PA 11 -PHL
35、PA 11 -P, EHL, 22-004 (PA 11 -PHL): 5.2 Requirements 5.2.1 Tensile strength Tubing and fittings shall resist a tensile force, F, in N, calculated according to the following equation (1): where o, = 20 N/mmz; d, s 5.2.2 Density When tested in accordance with subclause 5.3.2, fit- tings shall not work
36、 loose from the tube ends. is the nominal tubing outside diameter, in mm; is the nominal tubing wall thickness, in mm. 5.3 Testing 5.3.1 Tensile strength The tensile test is a class A test (cf. subclause 4.3) and determines the force required to pull the fittings from the tubing. Prior to testing, t
37、he specimens shall be conditioned in an oven for two hours at 100 “C and then cooled to room temperature. Testing shall be conducted at a rate of 25 mm/min. 5.3.2 Density The density test is a class A test (cf. subclause 4.3). Place three specimens (with end fittings) for each dimension in a forced-
38、circulation oven and heat at 125 “C for one hour. Then, subject the specimens to a test pressure which is 50 YO of the value specified in table 6, for five minutes at 125 “C. Cool specimens and condition them again for one hour in a refriger- ating chamber at -40 “C. Subject them to the same test pr
39、essure again for 5 minutes at -40C. I) At the users discretion. I I Page 6 DIN 74324-1 : 1996-02 6 Materials Tubing shall be of type PA 11 -PHL, PA 11 -PHLY, PA 12-PHL, PA 12-HIPHL or PA 12-PHLY moulding material as specified in table 1 of DIN 73378 (at the tube manufacturers discretion) and shall b
40、e stabilized against UV radiation, as specified in subclause 5.2.1.1 of DIN 73378. 7 Marking Tubing shall be indelibly marked at intervals of at least 350 mm (see example below). The marking shall be legible even after removal of any coatings. This marking shall have no detrimental effect on the mec
41、hanical properties or performance of the end fittings. EXAMPLE: DIN symbolLT T T T 1 - Standard number Nominal size (cf. table 1) Material (cf. clause 6) Manufacturers symbol Year of manufacture Month of manufacture DIN 74324 -8 x 1 PA 11-PHL ABC 95 M Other re1 evant standards DIN 74323 Coiled tubin
42、g for air braking systems DIN 7431 0-1 Hoses for use in air braking systems - Dimensions, materials and marking IS0 7628-1 : 1985 Road vehicles -Thermoplastics tubing for use in air braking systems - Part 1 : Dimen- sions and marking ISO/DIS 7628-2 : 1993 Road vehicles - Thermoplastics tubing for ai
43、r braking systems - Part 2: Mounting on vehicle and test methods Ex planat ory not es The requirements specified in this standard are intended to ensure the functional safety and interchangeability of air braking systems mounted on vehicles. In preparing this standard, other national standards and s
44、pecifications were consulted. A materials identifcation test was not included, as the materials which may be used for tubing in accordance with this standard are specified. Although the test for resistance to UV radiation specified here does serve to determine the resistance of the tubing material u
45、sed, it does not provide information regarding the service life of the tubing itself. Any paints, varnishes or solvents used should be tested for compatability with the tubing material to ensure that the tubing is not damaged. For information on the suppliers of radiators suitable for UV testing, contact the Normenausschu Krafffahr- zeuge (FAKRA) im DIN, Postfach 170563, D-60079 FrankfurVMain.
