Patent ID: 8286656

Claim:
A unidirectional pressure sensitive valve for placement in an environment such that during use the valve receives a first fluid and regulates flow of the first fluid therethrough, said valve comprising: a frame; and a number of flexible leaflets attached to said frame in a manner such that the number of flexible leaflets resist flow of said first fluid therethrough when in a first arrangement, provide minimal resistance to flow of said first fluid therethrough when in a second arrangement, and provide minimal resistance to flow of said first fluid therethrough when a failure occurs, in which when in the first arrangement the number of flexible leaflets resist flow of said first fluid therethrough in either a first direction or a second direction which is opposite to the first direction, and when in the second arrangement the number of flexible leaflets provide minimal resistance to flow of said first fluid therethrough in the first direction and prevent back-flow or the flow of said first fluid therethrough in the second direction, and in which each leaflet has a channel for receiving a second fluid such that during operation when desired to resist flow of said first fluid, the second fluid is caused to flow into each said channel so as to stiffen each said leaflet, and when desired to provide minimal resistance to flow of said first fluid, the second fluid is removed from each said channel.