High-pressure technology is the controlled application of high pressures. Bursting discs are used to protect the components of a pressure system against excessive pressures and pressure peaks.
Pressure systems, pressure vessels, safety valves and bursting disc equipment are subject to technical regulations and rules which constantly need to be adapted to the latest state of technology.
Safety valves are valves which open automatically when the actuation pressure level is reached, and let the media escape into the atmosphere. The system is closed again when the pressure falls below the actuation level.
Bursting elements will be destroyed upon actuation and they release the relief cross-section in the range of milliseconds. In contrast to safety valves the relief cross-sections remain open after the burst disc assembly has reacted. The system is pressure-free. (see AD2000A1-sheet)
Safety valves in connection with bursting discs are used if unfavourable operating conditions may result in deposits, bonds or corrosion impacting the function of safety valves.
Bursting disc equipment must:
- be fitted with a bursting disc,
- whose material is unaffected by the filling (also taking into account any impurities which might occur) or by an industrial atmosphere; if necessary the disc must have a coating which can neither become porous nor split during bulging,
- whose clamping force is created by torque wrenches when necessary
- be designed in such a way that the bursting disc has a concentric seat, can be fitted to parallel faces, and is not damaged in pressure areas in which it merely bulges,
- be sealed tight in respect to the atmosphere until it reacts within the range of operating temperatures,
- release the necessary cross-section when the disc bursts; in the case of a disc which is supported against over-pressure, the reduction in the cross-section caused by the support must be taken into consideration,
- be protected against the disc fixing coming loose.
Bursting discs are basically made of corrosion-resistant materials such as stainless steel, nickel, nickel-base materials (e.g. Inconel, Hastelloy) Tantalum as well as in connection with corrosion-resistant plastics such as FEP and PTFE, so that a solution for nearly every application can be offered. The actuation pressure changes according to the temperature at the place of installation. Generally, the actuation pressure decreases as the temperature increases. Various metals react in different ways to temperature changes, such as nickel to stainless steel. The different material properties can be used meaningfully when selecting the bursting discs.