ABSTRACT OF THE DISCLOSURE A valve permits articles disposed within a sterilizercontainer to be exposed to an entire sterilization cycle, yetseals the sterilizer container upon completion of the cycle. The valve includes a housing which defines a passage throughwhich fluid can flow between the interior and exterior of thesterilizer container. A sealing member seals the passage aftera predetermined number of high and low pressure stages of asterilization cycle has been completed. A cam member is recip-rocated as the high and low pressure stages of the steril-ization cycle are performed, each reciprocation causing thesealing member to move one step closer toward sealing thesterilizer container. Apparatus is provided to permit thevalve to be reset for further use of the container.