Patent ID: 6913168

Claim:
A pressure-activated valve for use with a container for dispensing fluid materials, the valve comprising: a base comprising a portion for covering an end of the container and a valve seat, the covering portion having an aperture; a cap mounted to the base and comprising a sidewall, a flexible annular portion extending radially inward from the sidewall and terminating in a valve rim, the flexible portion being configured to flex downward when subjected to pressure from the container fluid material, and means for attaching the cap to the base such that the cap can be rotated with respect to the base; and means for retaining the flexible annular portion in an un-flexed position; wherein rotating the cap causes the retaining means to disengage, enabling the flexible annular portion to flex downward when subjected to pressure from the container fluid material to expose an annular opening between the valve rim and the valve seat through which fluid may flow.