Abstract: A fluid control valve and manufacturing method thereof, wherein, when a pressing force acts on the engagement surface between a diaphragm member and a valve seat-contacting member, the valve seat-contacting member is not displaced and no gap is formed. The diaphragm member made of a first fluorine-based resin material is provided with a diaphragm membrane and a rod-shaped part in the center of the diaphragm membrane. The valve seat-contacting member made of an injection-moldable second fluorine-based resin material is provided with a ring-shaped sealing surface and a recess on the opposite side from the ring-shaped sealing surface. The rod-shaped part is partly fitted into the recess. A ring-shaped recessed is formed on outer circumference of a portion of the rod-shaped part. A small diameter recess is formed on the inner circumference of the recess. The ring-shaped recess section and the small diameter recess adhere closely to form the engagement surface.

Abstract: A fluid control valve and manufacturing method thereof, wherein, when a pressing force acts on the engagement surface between a diaphragm member and a valve seat-contacting member, the valve seat-contacting member is not displaced and no gap is formed. The diaphragm member made of a first fluorine-based resin material is provided with a diaphragm membrane and a rod-shaped part in the center of the diaphragm membrane. The valve seat-contacting member made of an injection-moldable second fluorine-based resin material is provided with a ring-shaped sealing surface and a recess on the opposite side from the ring-shaped sealing surface. The rod-shaped part is partly fitted into the recess. A ring-shaped recessed is formed on outer circumference of a portion of the rod-shaped part. A small diameter recess is formed on the inner circumference of the recess. The ring-shaped recess section and the small diameter recess adhere closely to form the engagement surface.

Abstract: A seal structure for connection sections, which facilitates installation and removal of a seal member from the connection sections. The seal member is placed in the connection sections between a first part and a second part. A first groove-ridge section is formed at the connection section of the first part, and a second groove-ridge section is formed at the connection section of the second part. The seal member has, on one face, a first fitting section fitting to the first groove-ridge section, and also has, on the other face, a second fitting section fitting to the second groove-ridge section. Press-fitting interferences in the wall-thickness direction are provided at the first and second fitting sections. The seal member has an extended section protruding radially outward from an annular body section where the first and second fitting sections are provided. The extended section protrudes to a position outside the connection sections of the first and second parts.

Abstract: A seal structure for connection sections, which facilitates installation and removal of a seal member from the connection sections. The seal member is placed in the connection sections between a first part and a second part. A first groove-ridge section is formed at the connection section of the first part, and a second groove-ridge section is formed at the connection section of the second part. The seal member has, on one face, a first fitting section fitting to the first groove-ridge section, and also has, on the other face, a second fitting section fitting to the second groove-ridge section. Press-fitting interferences in the wall-thickness direction are provided at the first and second fitting sections. The seal member has an extended section protruding radially outward from an annular body section where the first and second fitting sections are provided. The extended section protrudes to a position outside the connection sections of the first and second parts.