Rupture discs are also referred to as bursting discs or bursting diaphragms. The names describe the disc’s operation well. A rupture disc is a shaped metal or graphite disc on which a certain breaking point has been technically implemented. In a process pipe, the rupture disc is completely tight and keeps the pressure behind it until the breaking point is exceeded. If the set pressure is exceeded, the rupture disc breaks and releases the pressure from the system. When the pressure drops again, a new, intact disc is installed in the line.
Rupture discs can be equipped with detectors and/or gauges indicating the rupture of the disc.
A rupture disc can be installed directly between flanges or into a special holder. Of these, the holder is a better solution, since it involves no risk of rupture pressure changes in the course of installation or use. A rupture disc installed between flanges often requires a special elevation ring for maintenance works.
Explosion vent panels function in a similar manner, but are typically used for protecting structures against explosions (for example, dust explosions).
The choice is a sum of several subfactors
Especially in large size classes, rupture discs are significantly lighter than safety valves of the respective size.
Various aspects should be considered when dimensioning and selecting the rupture disc. These include, for example, operating pressure, rupture pressure required, pulsating or even load, need for vacuum protection, whether fragmentation is allowed upon rupture, use with liquid/gas, etc. Rupture discs have different manufacturing and rupture tolerances, which nowadays are included under an operating range tolerance (min./max.). Our sales personnel will dimension and select a suitable and cost efficient rupture disc for you.
Material options include nickel, RST/HST, hastelloy, Inconel, Monel, tantalum, titanium, silver, gold, graphite, etc.
Examples of media include vapours, other gases, liquids, (liquid) nitrogen, oxygen, carbon dioxide, ozone, helium, fuels, cryogenic fluids, etc.
Link: Grounds for rupture disc selection, blog text