Patent ID: 7240740

Claim:
A valve for controlling fluid flow, said valve comprising: an inlet duct; an outlet duct in fluid communication with said inlet duct; a seat positioned between said inlet duct and said outlet duct; a pressure chamber positioned in facing relation with said seat; a closure member positioned between said pressure chamber and said seat and having a seat engaging surface facing said seat, said closure member being pivotable about an axis to bring said seat engaging surface into and out of sealing engagement with said seat to open and close said valve; and a diaphragm sealingly partitioning said pressure chamber from said outlet duct, said diaphragm being positioned between said pressure chamber and said closure member and attached thereto, said diaphragm being flexible and transferring pressure from said pressure chamber onto said closure member, said closure member being pivoted into sealing engagement with said seat when said pressure chamber is pressurized, thereby closing said valve, said closure member being pivotable out of engagement with said seat when said pressure chamber is depressurized, thereby allowing said valve to open.