High-temperature diaphragm valve

A high-temperature diaphragm valve comprising:

• a holder that is suspended by a diaphragm that hermetically seals a valve chamber and moves to a valve opening/closing position in conjunction with a stem with a seal member to be brought into contact with a valve seat surface during valve closing held therein;
• and
• a pulling-up/aligning mechanism that connects the stem and the holder to each other, wherein
• the pulling-up/aligning mechanism includes
• a diaphragm piece that sandwiches an inner peripheral edge of the diaphragm, an outer peripheral edge of which is held in a body, between the diaphragm piece and the holder, and
• a connection member that is arranged in a loosely fitted state between a lower end recess provided in the stem and an upper end recess provided in the diaphragm piece and to connect the stem and the diaphragm piece to each other and contacts both respective bottom surfaces of the lower end recess and the upper end recess to transmit an axial force of the stem to the diaphragm piece by downward movement of the stem for valve closing,
• the connection member has an elongated hole-shaped connection through hole, a width in an axial direction of the connection member of which is larger than a diameter of the connection pin, formed therein in a direction substantially perpendicular to the axial direction of the connection member and is connected to the diaphragm piece via the connection pin inserted into the connection diaphragm piece, and
• the holder is forcibly pulled up by the pulling-up/aligning mechanism during valve opening, and the seal member held in the holder by the pulling-up/aligning mechanism seals the valve seat surface with a uniform force during valve closing.