US Patent 7628376 Diaphragm valve

A diaphragm valve having a diaphragm valve element including a valve element body movable into contact with a valve seat, a web portion extending outward from the valve element body, and a fixed portion formed at an outer peripheral edge of the web portion. The web portion includes a vertical portion vertically formed continuous with the valve element body, a horizontal portion horizontally formed continuous with the fixed portion, and a connecting portion of a circular arc shape (an upward protruding shape) in section to connect the vertical portion with the horizontal portion, thereby holding the vertical portion in constant contact with an outer surface of a backup.