BS ISO 4708-2015 pdf download.Composition cork – Gasket material一1 Test methods. 7.6 Flexibility 7.6.1 Method A 7.6.1.1 Procedure Firmly hold the test specimen at one point on a circular mandrel (4.1) and slowly but firmly, under finger pressure, force the test specimen to contact 1800 of the lull mandrel diameter for approximately (5 ± 1) s. Repeat this flexure using decreasing mandrel diameters on new test specimens until failure (3.3) occurs. 7.6.1.2 Calculation and expression of results The test result is the minimum diameter, expressed in millimetres, on which the test specimen could be flexed without any signs of failure (3.3). A flexibility factor may be calculated by dividing this minimum diameter by the nominal thickness of the test specimen. 7.6.2 Method B 7.6.2.1 Procedure Place the test specimens in the oven (42) set at (100 ± 2) °C, for 70 h. After this period, remove the test specimens, allow them cool for (24 ± 1) h under laboratory ambient conditions. Carry out the test as specified in 7.6.1.1. 7.6.2.2 Calculation and expression of results The test result is the minimum diameter, expressed in millimetres, on which the test specimen could be flexed without any signs of failure (ii). 7.7 Behaviour of composition cork and rubbercork in fluids These test methods provide a standardized procedure to measure the effect of immersion in specified fluids under definite conditions of time and temperature. The test results are not intended to give any direct correlation with service conditions, taking into account the wide variations in temperature and special use that may be found in gasket applications. The specific test fluids and test conditions outlined were selected as typical for purposes of comparing different materials and may be used as a routine test when agreed between the interested parties. 7.7.1 Behaviour in ASTM IRM 903 oil 7.7.1.1 Procedure The test specimens shall have the dimensions defined in Table 1 and the material thickness defined in Table 2. The test specimens shall be conditioned before the test as specified in 63. Determine the thickness of the test specimens as specified in Li. Place the test specimens in the containers (4.3) with ASTM IRM 903 oil (or equivalent), for 72 h, at ambient temperature (between 22 °C and 30 °C). At the end of this period, remove the test specimens, clean them with absorbent paper (4.5) and determine the new thickness of the test specimens.BS ISO...
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