Abstract: A rupturable fluid pressure relief apparatus and method of manufacturing such apparatus capable of rupturing in either the normal or reverse rupture modes at predetermined rupture pressures are provided. The apparatus is basically comprised of a circular rupture disk positioned between a pair of annular rupture pressure control members. The rupture pressure control members include centrally positioned circular openings therein of sizes such that the rupture disk ruptures at predetermined rupture pressures or pressure differentials exerted from either side of the rupture disk.

Abstract: Rupturable pressure relief apparatus are provided which are less subject to damage and premature failure as a result thereof and which reliably rupture at very low pressure differentials. The apparatus are adapted to be clamped between conventional pipe flanges or annular support members and are basically comprised of a first circular rupturable member formed of solid flexible material and a second circular rupturable member also formed of flexible material positioned adjacent the first rupturable member. The second rupturable member includes a solid annular flange portion and a plurality of arcuate slots circumscribing a substantially circular central portion wth rupture tabs between the arcuate slots. Knife means having a cutting edge forming at least a portion of a circle are positioned adjacent the second rupturable member on the side thereof opposite from the first rupturable member so that when the second rupturable member ruptures, the first rupturable member is severed by the knife means.

Abstract: A rupturable pressure relief apparatus which is non-fragmenting and which is particularly suitable for liquid and low pressure gas service. The apparatus includes an annular rupture disk having an annular flange portion connected to a concave-convex portion by a circular transition connection. The concave-convex portion includes a groove in a side thereof creating a substantially circular line of weakness therein and at least one concave-convex hinge reinforcing member is attached to a side of the concave-convex portion of the rupture disk. The hinge reinforcing member is positioned and is of a shape whereby upon rupture of the rupture disk, the concave-convex portion tears along the line of weakness created by the groove and bends about an integral untorn portion corresponding with the hinge reinforcing member.

Abstract: An improved reverse buckling rupture disk apparatus which includes a reverse buckling rupture disk, an annular rupture disk support member and knife structure for severing the rupture disk upon the reversal thereof. The knife structure are comprised of at least three blade legs having sharpened cutting edges formed thereon facing the rupture disk attached together at the internal ends thereof and attached to or supported by the annular support member at the external ends thereof. Each of the blade legs has at least a portion of the cutting edge thereof inclined towards the rupture disk from the internal end to the external end thereof whereby upon reversal of the rupture disk, the rupture disk is progressively severed by the cutting edges of the blade legs from points near the periphery of the reversing portion of the rupture disk to the center of the rupture disk.

Abstract: A four way reversing valve utilized in the refrigerant flow system of a heat pump or the like for selectively directing the flow of high pressure refrigerant either to the inside or outside heat exchange coil of the heat pump thereby to selectively either effect heating or cooling of the space in which the inside coil is located. The valve has an improved slide valve design which significantly lessens flow losses through the valve.