US Patent 10054234 One-way valve

A one-way valve, comprises a valve housing; a valve member provided within the valve housing, the valve member being operative to open and close the valve and comprising a diaphragm with a central orifice to allow fluid to pass from one side of the diaphragm to the other; a valve inlet provided on a first side of the diaphragm; and a valve outlet provided on a second side of the diaphragm; wherein the configuration of the diaphragm and the valve housing biases the diaphragm to seal the inlet at rest.