Pressure-responsive valve

A closure for sealing a passageway from the flow of fluid therethrough, said closure comprising an elastically deformable diaphragm made of material impermeable to said fluid, said diaphragm having a plurality of non-intersecting, non-meeting, separate slits, each slit having a base which is intersected by at least one other slit, and each slit being out of intersecting relation with its own base, wherein said slits only partially penetrate said diaphragm whereby to maintain the impermeability thereof, the material being readily severable at said partially penetrating slits whereby to convert said closure into a pressure-responsive valve.

A closure for sealing a passageway to the flow of fluid therethrough, said closure comprising an elastically deformable diaphragm formed of fluid impermeable material, said diaphragm having at least three non-intersecting, non-meeting, separte arcuate slits, each slit having a base which is intersected by at least one other slit, and each slit being out of intersecting relation with its own base, wherein said slits only partially penetrate said diaphragm for creating a closure which is breakable along said partially penetrating slits for converting said closure into a pressure-responsive valve.