PURPOSE: To provide a valve device whose fluid path is blocked by protruding a valve element to the confronting space of the primary side and the secondary side valve seat furnished in a valve box so that the valve element is put in pressure contact with valve seat, in which the valve element and/or valve seats are prevented from seizure by hindering the valve element from sliding relative to valve seat.

CONSTITUTION: A primary side valve member 65 and a secondary side valve member 66 to constitute a valve element are coupled together by a middle folded two-gang link 15. A valve stem 7 is coupled with this link 15 at its bent point 18. When having reached the position capable of blocking fluid passages 2, 3, the valve members 65, 66 collide with the inner surface 11 of the valve box 1 to restrict its positioning.