Patent ID: 6997440

Claim:
Valve apparatus for controlling fluid flow, comprising a valve body having a central axis, a valve base having a first port and a second port in fluid communication with the first port, a valve seat disposed between the first and second ports for having fluid in flowing from the first port to the second port flow through the valve seat, wherein the flow is surrounded by the valve seat, a diaphragm mounted by at least one of the base and body and movable between a valve closed position blocking fluid through the valve seat from the first port to the second port and a valve open position permitting fluid flow through the valve seat, said diaphragm having a central concave portion opening toward the valve seat, a button having a central axis and mounted for axial movement by the valve body for abutting against the diaphragm to move it from its open position to its closed position, said button having a first surface for abutting against the diaphragm, the button first surface in the valve open position having a central concave portion opening to the diaphragm central portion and an annular convexly curved portion joined to the button concave portion and surrounding the button concave portion for abutting against the diaphragm as the diaphragm is moved from its open position to its closed position and means for moving the button from its valve open position to its closed position.