ISO 2758:2014 pdf free

ISO 2758:2014 pdf free.Paper一Determination of bursting strength
Any clamping pressure-indicating device fitted should preferably be scaled to indicate the actual clamping pressure, not the pressure in the clamping system itself. The clamping pressure may be calculated from clamping-force and clamp-area information.
Diaphragm, circular, of natural or synthetic rubber, free from filler orloading and 0,86 mm±0,06 mm thick, clamped securely with its outer surface, when at rest, recessed about 3,5 mm relative to the outer plane of the diaphragm-mounting plate.
The material and construction of the diaphragm shall be such that the pressure required to bulge the diaphragm 9,00 mm±0,2 mm outside the outer plane of the diaphragm plate is 30 kPa±5 kPa.Diaphragms in use shall be regularly checked and changed if the bulge-height requirement is no longer met.
The apparatus should be ftted, or able to be fitted, with suitable test points to facilitate checking of the fluid pumping rate, calibration of the maximum pressure-measurement and display system and calibration of the clamping-pressure-indicating device where fitted.
Calibration shall be carried out before initial use and at sufficiently frequent intervals to maintain the specified accuracy. Wherever possible, calibration of the pressure-sensing device should be carried out with it mounted in the same position it occupies on the apparatus and preferably on the apparatus itself.
If necessary, zero the hydraulic-pressure-indicating device according to the manufacturer’s instructions.Apply hydraulic pressure until the test piece bursts. Retract the piston until the diaphragm is below the level of the diaphragm-clamping plate. Read the indicated bursting pressure to the nearest kilopascal.Release the clamp and prepare the instrument for the next test. Readings shall be rejected when visible slippage of the test piece (as shown by movement of the test piece outside the clamps or by creasing of the test piece in the clamped area) has ocurred. In cases of doubt, the use of a larger test piece will frequently establish whether slippage is occurring. Readings shall be rejected if the type of failure (for example, severance at the periphery of the test zone) indicates that the test piece was damaged by excessive clamping pressure or rotation of the clamps during clamping.ISO 2758 pdf free download.