BS EN 15328:2020 pdf free.Railway applications一Braking一Brake pads.
BS EN 15328 The tolerance ranges for the instantaneous and mean coefficients of friction on a dry brake disc are given for the respective applications in the figures of the corresponding annexes. The instantaneous and the mean coefficients of friction measured in the test bench tests shall be documented in the appropriate tolerance diagrams. For the highest nominal application forces of the test program the mean coefficients of friction are summarized in a separate tolerance diagram and documented in tabular form. The average value of these mean cofficients of friction at a speed of 120 km/h at the highest nominal application force (excluding brake application with high initial temperatures) shall not vary more than 10 % upwards or 5 % downwards from the nominal coefficient of friction given in the tolerance diagram of the respective test program. At speeds above 120 km/h, the average values of these mean coefficients of friction shall not vary more than 10 % upwards or 10 % downwards from the nominal coefficients of friction.For brake applications to a stand, which are done from a high initial temperature (approximately 140 °C,excluding brake application after continuous brake applications and for two consecutive emergency brake without cooling time], the mean coefficient of friction under otherwise similar conditions shall not vary by more than士15 % from the average of the mean coefficients of friction of brake applications initiated from the cold and dry condition.5.6.6 Coefficient of friction under wet conditions
In wet conditions, with the highest nominal application force of test program S2.1 and T2 the mean coefficient of friction shall not vary – all other things being equal – by more than + 15 % compared with the average of mean coefficients of friction obtained during braking under dry conditions. The mean
coefficients of friction of the other brake applications to a stand of this test program shall not under-run the absolute value of μm = 0,250 under otherwise similar conditions.BS EN 15328 pdf download.