OVERVIEW

The use of a rupture disc is the most basic method of protecting a piping system from overpressurization. A rupture disc is a sacrificial component and after the disc has been ruptured during overpressurization, this component must be replaced to protect the vessel and the piping system.

Rupture discs are the pressure and temperature sensitive element of non-reclosing pressure relief devices, consisting of the rupture disc and a holder. They are designed to protect pressure systems against damage from excessive overpressure or vacuum by bursting at a predetermined pressure differential across the disc.

The original rupture disc consisted of a plain metal sheet that was clamped between two flanges. When exposed to pressure on one side, the disc would stretch and form a hemispherical dome before bursting. The predictability of the burst pressure, however, was poor. To improve the predictability, rupture discs were subsequently predomed by applying pressure to one side of the disc that was higher than the normal operating pressure by some margin.

The rupture disc thus produced is today's solid-metal forward-domed rupture disc. Flat metal rupture discs have also been reengineered for low-pressure applications. Both types of rupture discs are of the tension-loaded type in which the fluid pressure stretches the disc material as the fluid pressure increases.

The continuing effort to raise the operating ratio of rupture discs led to the development of reverse-buckling discs. This type of disc is domed against the fluid pressure so that the fluid pressure introduces a compression load on...