Abstract: Provided is a fluid control device that is compact and that enables data regarding an internal operation of the device to be acquired. A fluid control device V is disposed in a flow path of a fluid and enables data regarding an internal operation to be acquired, the fluid control device including a sensor hood 44 to which one or more sensors M2 for detecting an operation in the fluid control device are attached; a valve body 1 connected to the sensor hood; a diaphragm 42 held below the sensor hood, inside the valve body; a cover portion 5 that covers the outer periphery of the sensor hood; and a circuit board 60 that is electrically connected to the sensor(s) and for which a thickness direction of the circuit board and a flow path direction are arranged in the same direction on the inside of the cover portion.

Abstract: A valve which can accurately detect an operation of the valve is provided. The valve includes a valve body defining a fluid flow passage, a valve disk operating to be able to open and close the fluid flow passage, an actuator driving the valve disk by supplying or interrupting a working fluid, a stem transmitting a driving force of the actuator to the valve disk, a detection means detecting an opening and closing operation of the valve disk, and an elastic member fixing a ring-shaped magnetic body inserted through an end of the stem to the stem. The detection means includes the magnetic body fixed by the elastic member, and a magnetic sensor detecting a change in a magnetic field of the magnetic body.

Abstract: A bolt holding member is made of metal and holds a bolt in a fastened member. The bolt holding member includes: a main body portion that has a cylindrical shape; a first engaging piece that extends from the main body portion toward an inside of the main body portion at an incline relative to an axial direction of the main body portion; and a second engaging piece that extends from the main body portion toward an outside of the main body portion at an incline relative to the axial direction of the main body portion.