Regelventil

摘要

A control valve comprises a valve body having a fluid channel and a valve seat; a valve operating part; a valve stem supporting member having its upper end fixed to the valve operating part and its lower end fixed to the valve body; a valve stem penetrating the valve stem supporting member and having its upper end part connected to the valve operating part and its lower end part entering the valve body, the valve stem being movable upward or downward by the valve operating part; and a valve element attached to the lower end of the valve stem. The valve element is moved upward or downward by moving the valve stem upward or downward, the valve element being brought into contact with and seated in the valve seat to close a fluid channel as it is moved downward, the valve element being detached from the valve seat to open the fluid channel as it is moved upward. The valve stem comprises an upper bar-shaped member of metal connected to the valve operating member and a lower bar-shaped member made of a fiber reinforced plastic to which the valve element is attached. The upper and lower bar-shaped members are movable upward from a lower end position where the valve element is in a fully open state. The lower bar-shaped member is stop from moving upward at an upper end position where the valve element is in a fully open state. An uppward moving distance of the upper bar-shaped member from a lower end position is made longer than a moving distance of the lower bar-shaped member from the lower end position to the upper end position.