High flow pressure relief assembly

Abstract

A safety pressure relief assembly of the rupture disc type guards against pressure differentials, beyond a predetermined range in a vent system, and includes a relief disc perforated to permit reverse flow without rupture, a sealing disc positioned adjacent the relief disc and blocking positive flow through the perforations, a support member with a stay structure positioned to support the sealing disc nested within the relief disc, and a cutting member positioned to cut the sealing disc at a predetermined vacuum within the vent system. The relief disc has a concave surface and a convex surface. When a predetermined vacuum pressure differential is applied to the assembly, the sealing disc and the support structure are inverted to project away from the relief disc. During the inversion, the support structure is recessed between cutting blades of the cutting member and the sealing disc impacts the cutting blades and is cut thereby into a pattern having petals and a silhouette portion in the shape of the support structure. As fluid under pressure flows through the rupture disc assembly, the silhouette portion of the sealing disc is supported by the support structure and is located between the cutting blades. After cutting by the blades, the petal portions are no longer supported by the support structure and fold out of the way of the fluid to open channels or passageways through the rupture disc assembly and permit rapid equilibration of pressure between opposite sides of the system without loose portions of the assembly being formed.