Patent ID: 8408515

Claim:
A pressure-reducing valve in which a peripheral edge part of a diaphragm is clamped between a body housing a valve mechanism and a diaphragm cover fixed to the body, the diaphragm forming a pressure action chamber between the diaphragm and the body and forming a spring chamber between the diaphragm and the diaphragm cover, a spring housed in the spring chamber is provided in a compressed state between the diaphragm cover and the diaphragm, and a diaphragm rod connected to a central part of the diaphragm is connected to a valve body of the valve mechanism, wherein the diaphragm is formed from a disk-shaped rubber sheet and a sheet thickness of at least the peripheral edge part of the diaphragm is uniform in a natural state, the diaphragm cover integrally has a bottomed cylindrical portion having an end wall portion in an end part opposite the diaphragm and a collar portion protruding radially outward from an open end of the bottomed cylindrical portion, the body is formed with a clamping face holding the peripheral edge part of the diaphragm ( 28 ) between the clamping face and the collar portion, the clamping face has a chamfered portion positioned radially outward on an outer periphery of the clamping face with the peripheral edge end part of the diaphragm extending over the chamfered portion, the diaphragm cover is fixed to the body radially outward of the chamfered portion and the peripheral edge part of the diaphragm is compressively held between the clamping face and the collar portion at a position radially inward of the chamfered portion.