Abstract: A valve device using pipe materials in which a fluid control mechanism is arranged and which comprises a valve device body (11) made of a metallic pipe material and having a tubular flange (21) integrally formed on the outer surface of the body so as to protrude therefrom, and a tubular member (12) for forming a flow passage, which is fitted and connected at the base end thereof to the top end of the tubular flange (21). The tubular flange (21) is formed so that the area of the opening at the base end thereof communicating with the flow passage within the valve device body is greater than the area of the opening at the top end of the tubular flange. The inner peripheral portion (21a) of the base end of the tubular flange (21) is formed with a smoothly curved surface, and the flow passage is formed along such a curved surface.

Abstract: An oxygen sensor device is disclosed having a glass dome fluid-tightly connected at its circumferential base edge to one surface of an oxygen conductive solid electrolyte plate to form a diffusion chamber defined by the glass dome and the solid electrolyte plate. The diffusion chamber may be vacant, or may have a porous inorganic material packing layer fixedly disposed in the entire space thereof. Alternatively, the diffusion chamber may have a porous inorganic material semi-packing layer fixedly disposed in an upper portion thereof remote from the electrolyte plate, while leaving vacant the remainder of the chamber. The oxygen sensor device is advantageous from the viewpoints of miniaturization, power consumption saving and reliability.