Knife blade apparatus for severing rupture disks

#1. Field of the Invention

#The present invention relates to improved knife blade apparatus for severing rupture disks, and more particularly, but not by way of limitation, to an improved knife blade apparatus adapted to be installed in a reverse buckling rupture disk assembly.

#2. Description of the Prior Art

#FIG. 1 is a side cross-sectional view of a reverse buckling rupture disk assembly including the improved knife blade apparatus of the present invention clamped between a pair of companion flanges.

#FIG. 2 is a cross-sectional view of the assembly of FIG. 1 taken along line 2--2 of FIG. 1.

#FIG. 3 is a side cross-sectional view of an alternate form of the improved knife blade apparatus of the present invention.

#Referring now to the drawings and particularly to FIGS. 1 and 2, a reverse buckling rupture disk assembly including the improved knife blade apparatus of the present invention is illustrated and generally designated by the numeral 10. The assembly 10 is shown clamped between a pair of companion inlet and outlet flanges 12 and 14, respectively, which are in turn attached to inlet and outlet conduits 16 and 18, respectively. As is well understood by those skilled in the art, the inlet conduit 16 is connected to a vessel or system containing fluid under pressure whereby such pressure is communicated to the rupture disk assembly 10. When the pressure exerted on the rupture disk assembly 10 exceeds the predetermined design rupture pressure thereof, the rupture disk assembly opens whereby fluid pressure is relieved through the assembly and led to the atmosphere or to another vessel or system for receiving relieved fluids by the conduit 18.

#The rupture disk assembly 10 and conventional gaskets 11 and 13 are clamped between the flanges 12 and 14 by a plurality of studs 20 and nuts 22 positioned in openings around the peripheries of the flanges. The assembly 10 is comprised of an annular inlet support member 24, the knife blade apparatus of the present invention 25 which includes an annular outlet support member 26, and a reverse buckling rupture disk 28 positioned therebetween. The knife blade apparatus 25 includes knife blade means 30 positioned within the interior of the support member 26 whereby upon failure of the rupture disk 28, i.e., the reversal thereof due to excess fluid pressure being exerted thereon, the rupture disk 28 contacts the knife blade means 30 and is severed thereby allowing fluids under pressure to be relieved through the assembly 10. As mentioned above, the rupture disk assembly 10 can take various other forms, e.g., more than one rupture disk can be utilized in the assembly, and the support members 24 and 26 can take various other forms.

#Refering now to FIGS. 5 and 6, the most commonly used prior art knife blade apparatus is illustrated and generally designated by the numeral 40. The apparatus 40 includes an annular rupture disk support member 42 adapted to be installed in a rupture disk assembly of the type illustrated in FIGS. 1 and 2 with knife blade means, generally designated by the numeral 44, welded to the interior thereof. The knife blade means 44 are comprised of four sharpened blade legs 46, the interior ends of which are welded together at right angles to each other and the exterior ends of which are welded to the interior of the annular support member 42. The sharpened blade legs 46 are positioned across the opening in the support member 42 and the apparatus 40 is installed in a rupture disk assembly whereby the sharpened portions of the blade legs 46 face the rupture disk to be severed thereby.