To extremely suppress exertion of an adverse influence on responsiveness by an elastic force produced by a diaphragm and avoid reduction of a control gas pressure in a pressure reducing chamber according to increase in a gas flow rate, in a pressure reducing valve for gas formed that a pressure reducing chamber to generate a gas pressure exerted on one surface of the diaphragm is formed in a valve housing for nipping the peripheral edge of the diaphragm, a valve element capable of seating a valve seat where a valve hole communicating with the pressure reducing chamber is opened at a central part has one end coupled to the central part of the diaphragm and is fixed at the other end of the valve stem axially movably extending through the valve hole, and a spring to energize a diaphragm in a direction in which a valve element is separated from a valve seat is contained in a spring chamber formed in a valve housing in a state to front on the other surface of the diaphragm.
The diaphragm 146, the valve stem 168, and the valve element 165 are assembled such that the valve element 165 is situated in a position spaced away from the valve seat 163 when during assembly to a valve housing 140, the diaphragm 146 is situated in a natural state that exertion of an external force is avoided.
ISHIKAWA KAZUNORI
SAITO YOSHIO
