Temperature influence

The burst pressure of metal bursting discs is influenced by the prevailing temperature at the bursting disc when reacting. With increasing temperature the strength of the metallic material decreases which leads to a lower response pressure of the bursting disc. This will pose no problem with regard to the safety requirements as the bursting disc opens below the pressure critical for the facility to be protected. If, however, a bursting disc is designed for a higher temperature than the one actually prevailing at the bursting disc in operation, the bursting disc will react at a higher pressure than intended. The temperature influence depends on the material used but may range up to 18 per cent of the bursting pressure when deviating by 100 K from the design temperature, depending on the material and the type of bursting disc. This is why the correct temperature at which the bursting disc reacts is that crucial. For bursting discs made of graphite the influence is considerably smaller, if not completely negligible. Therefore graphite bursting discs are an excellent alternative to metal bursting discs whenever the temperature at which the bursting disc reacts cannot be foreseen.