SAFETY PRESSURE RELEASE DEVICE

摘要

A safety pressure relief device including a rupture disk having a concave-convex portion and a radially outer flange portion joined by a curved transition connection. An improved knife means is located adjacent the concave side of said rupture disk, said knife means including a radially outer flange portion which supports said curved transition connection. A substantially circular inner opening is disposed in said knife means. Said knife means includes first and second spaced cutting means projecting radially inward into said opening and inclined towards said concave portion of said rupture disk. Said knife means further includes first and second arcuate non-cutting portions each partially defining said inner opening. The first cutting means is located between said first and second non-cutting portions so that upon reversal of said rupture disk said first and second cutting means will puncture said rupture disk without severing a portion of the disk therefrom.