Abstract: A valve control apparatus including: an operating time measurement unit that measures an operating time of a valve based on an operation pressure of the valve and whether the valve is open or closed; and a command control unit that receives an opening command directed to the valve and transmitted from a control apparatus, and transmits the opening command to the valve in a delayed manner based on the operating time and a predetermined reference time.

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 diaphragm includes: a metal thin plate; and a thin film layer formed over an entirety of a surface on one side of the thin plate.

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.