A dispensing system is provided for a container having an opening to the
container interior. The dispensing system includes a closure with an
elevator that is disposed within the container opening for movement
between a fully elevated position and a fully lowered position while the
elevator is restrained by the container from rotating. The elevator has a
seat defining an inlet passage and has a thread. A rotatable housing is
mounted on the container at the opening and has a thread engaged with the
elevator thread. The housing has a dispensing passage and an occlusion
member. The occlusion member sealingly engages the elevator seat and
prevents flow through the elevator inlet passage when the elevator is in
the fully elevated position. When the elevator is moved away from the
fully elevated position by rotation of the housing, flow is permitted
through the inlet passage and into the housing dispensing passage. A
flexible dispensing valve is sealingly secured across the dispensing
passage in the housing. The valve has a self-sealing slit which opens to
permit flow therethrough in response to increased pressure on the side of
the valve facing the interior of the container.