A valve assembly (10) is provided which includes a housing (11) having an inlet end and an outlet end and defining a fluid channel (18) and a central chamber (34). A dissolvable valve member (16) is positioned to obstruct flow through the channel within the chamber. The dissolvable valve member is formed of a material which is dissolvable at a predetermined rate upon contact with a preselected fluid. The preselected fluid is selected from the group consisting of blood, urine, saline and antimicrobial solutions. The dissolvable valve member can be formed from a fluid soluble glass or a starch based material.
