A valve comprises a flexible member including a slit formed on a central portion thereof and a first housing defining a first lumen extending therethrough, the first housing including a first contacting surface adapted, when the slit of the flexible member is aligned with the first lumen, to contact a first side of the flexible member the first housing defining a relief area extending about a perimeter of the first contacting surface radially outside the central portion relative to a longitudinal axis of the first lumen in combination with a second housing adapted to mate with the first housing with a second lumen defined by the second housing aligned with the first lumen and separated therefrom by the flexible member, the second housing including a second contacting surface.
