ISO 07628:2010 pdf free download – Road vehicles一Thermoplastics tubing for air braking systems.
9.13 Heat ageing
9.13.1 Procedure
The applied materials shall comply with this International Standard, including thermoplastic adhesive materials
used to join together any dissimilar material layers.
9.13.2 Requirement
The long-term heat ageing test and properties are to be specified by the end user.
9.14 Artificial weathering test
9.14.1 Procedure
Use a suitable radiation source with reproducible spectrum and constant output as specified in ISO 4892-2, preferably a xenon arc test cabinet. The use of other cabinets using other types of light sources, for example an open-flame carbon arc, is in principle acceptable but shall be agreed upon between the tube manufacturer and the end user.
Place three samples of the tube of about 150 mm length facing the lamp, ensuring that there is no movement of the samples during the test.
Expose samples to radiation according to method A of ISO 4892-2:2006 or ISO 4892-4:2004 with 550 W/m2 irrad iance:
a) for 750 h with the xenon arc lamp, at (65 ±3) °C or
b) for 400 h with an open-flame carbon arc lamp, at (65 ± 3) °C.
The test shall be carried out with water spray cycles, (18 ± 0,5) mm spraying time and (102 ± 0,5) mm dry interval, at a relative humidity of (65 ± 5) % for the dry interval.
Remove the samples from the cabinet and then assemble with end fittings. Subject the samples to a burst test at a temperature of 23 °C (in accordance with 9.1.2).
9.14.2 Requirements
All samples shall withstand
4 000 kPa (40 bar) for 1 000 kPa (10 bar) tubes;
5 000 kPa (50 bar) for 1 250 kPa (12,5 bar) tubes;
and at least 80 % of the burst pressure at 23 °C initially measured on samples from the same batch. The burst area shall be ductile. Brittle fractures shall be regarded as failures.
9.15 Ozone test
9.15.1 Procedure
Subject the air brake tube hose to an ozone concentration of 100 pphm for 70 h at 40 00 according to FMVSS No. 1060 where the hose is secured around a mandrel 10 x the outer diameter of the tube.
B.2 Leak test
B.2.1 Procedure
The test shall be carried out on three tube assemblies and consists, depending on the temperature class, of a temperature cycle from 80 °C, 100 °C or 125 °C to —40 °C. The tube assemblies shall be held under pressure with inert gas or dry air. The free length of the tube shall be at least 150 mm.
Place three specimens with end fittings in a forced-circulation oven and heat at 80 °C, 100 °C or 125 °C depending on the temperature class. When the temperature is reached, subject the specimens to a test pressure of twice the working pressure for 5 mm at the required temperature, 80 °C, 100 °C or 125 °C according to the temperature class. Cool and condition the test specimen for one hour at —40 °C. Subject the specimen to a test pressure of twice the working pressure for 5 mm at —40 °C.
Condition the specimen at 23 °C for 1 h. Subject the specimens to the working pressure and check on leakage using leakage detection spray.
B.2.2 Requirement
The test specimens shall show no leakage.
B.3 Vibration test
A vibration test shall be performed on the tube assembly.
Until such time as appropriate test procedure(s) and performance requirement(s) have been agreed upon, it is
necessary that either an existing national standard or a vehicle manufacturer’s internal specification be used.
BA Pulsating pressure fatigue test
B.41 Procedure
This test shall be carried out on three tube assemblies where the pipe length between the pipe fittings shall be at least 300 mm. The test set-up is schematically shown in Figure B.1.
Test conditions:
pressurizing medium: inert hydraulic fluid.