Relief valve for use with hermetically sealed flexible container

A pressure relief valve for use with a sealable flexible container for storing and transporting food stuffs such as coffee, said pressure relief valve comprising:

• a valve body having an inlet surface, a valve seat surface, at least one gas inlet passageway between said inlet surface and said valve seat surface, said valve body includes a recess, said recess formed by said valve seat surface, at least one enclosing sidewall and substantially open opposite said valve seat surface, said said at least one enclosing sidewall includes at least one valve diaphragm retaining boss extending radially inwardly;
• and
• a valve diaphragm formed from a resilient material, said valve diaphragm being substantially flat and having a valve seat contacting surface, said valve seat contacting surface being coated with a viscous liquid, said valve diaphragm being sized to avoid contact with said at least one enclosing sidewall, when substantially centered on said valve seat, and large enough that the resilient diaphragm is deformed will being inserted past said at least one valve diaphragm retaining boss, said at least one valve diaphragm retaining boss being spaced from said valve seat that said resilient diaphragm does not contact the diaphragm retaining boss in normal operation, normal operation being that pressure is relieved by said resilient diaphragm deforming such that only a portion of the diaphragm lifts off of the valve seat thereby allowing pressure release, the diaphragm retaining boss only present to prevent an unlikely dislodging of the diaphragm during installation of the valve onto an inner wall of the sealable flexible container.