VALVE FOR CONTAINER FILLED WITH HALOGEN GAS OR HALOGEN COMPOUND GAS

摘要

A direct-touch diaphragm valve according to the present invention includes a valve body having inlet and outlet passages, a valve chamber being in communication with the inlet and outlet passages, a valve seat located around an open inner end of the inlet passage, a diaphragm arranged on the valve seat so as to hermetically seal the valve chamber and open or close the inlet and outlet passages, a stem adapted to move a center portion of the diaphragm downwardly and a driving unit adapted to move the stem in a vertical direction, wherein the valve seat and the diaphragm have respective contact surfaces formed therebetween such that: such that: the contact surface of the valve seat has a surface roughness Ra of 0.1 to 10.0 µm and a curvature radius Ra of 100 to 1000 mm; and the area ratio Sb/Sa of a contact area Sb of the valve seat with the diaphragm to a gas contact surface area Sa of the diaphragm ranges from 0.2 to 10%. The valve according to the present invention attains sufficient gas tightness and can suitably be applied to a halogen gas- or halogen compound gas-filled container.