Patent attributes
A valve device includes a valve body; a valve seat; an inner disk made of a metal alloy having an inner annular portion, outer annular portion and a connecting portion that connects the inner annular portion and the outer annular portion; a diaphragm made of a metal alloy covering the inner disk and the valve seat and moving between an open position at which the diaphragm does not contact the valve seat and a closed position at which the diaphragm contacts the valve seat to enable and shuts off communication between the first flow path and the second flow paths; and a presser adapter that presses a peripheral edge portion of the diaphragm toward the outer annular portion; and the inner disk has a hardness higher than the valve seat and lower than both the valve body and the diaphragm.
