Patent ID: 8257321

Claim:
A valve comprising: a first housing including a first lumen extending therethrough and defining a first disk-facing surface; a second housing including a second lumen extending therethrough and defining a second disk-facing surface, the second housing being coupled to the first housing so that the second disk-facing surface faces the first disk-facing surface; a flexible disk gripped between gripping portions of the first and second disk-facing surfaces, the disk including a slit extending therethrough which, when acted upon by a fluid pressure of at least a predetermined threshold level opens to permit fluid flow between the first and second lumens and which, when acted upon by a fluid pressure less than the threshold level, prevents fluid flow between the first and second lumens; and a relief well between opposing portions of the first and second housings radially outside the gripping portions, a width of the relief well exceeding a width of a radially outer portion of the flexible disk so that the radially outer portion of the disk is free to move therewithin, the relief well including a first protrusion that deforms the radially outer portion of the flexible disk so that it extends away from a plane defined by a central portion of the disk.