Patent ID: 7299817

Claim:
A vent valve assembly comprising: a housing including an opening formed thereon, the housing defining an interior therein that is substantially evacuated; a vent valve coupled to the housing, the vent valve including: a valve housing including an inner surface, an outer surface, and an opening extending therebetween, the inner surface defining a cavity in fluid communication with the housing opening; a valve element disposed at least partially within the valve housing cavity and movable between a closed position, in which fluid is prevented from flowing through the valve housing opening into the housing interior, and an open position, in which fluid may flow through the valve housing opening into the housing interior; and bellows disposed at least partially within the valve housing and coupled to the valve element, the bellows having an internal chamber and configured to selectively move the valve element between the closed and open position in response to a differential pressure between the bellows internal chamber and the valve housing cavity.