| 摘要 |
(Abstract) (Problem) To provide a diaphragm valve having little fluctuation in sealing performance. (Solution) A diaphragm valve provided with: a body comprising an inlet flow channel, an outlet flow channel, and a valve seat provided between these passages; a diaphragm of which the middle part moves up and down and comes into contact with the valve seat; a stem connected to the middle part of the diaphragm, the stem extending upward, and provided to be free to rise and fall; an operation mechanism for raising or lowering the stem; and a diaphragm press for pressing the diaphragm when the stem is lowered, the diaphragm press being provided adjacent to the upper surface of the diaphragm, wherein the diaphragm valve is characterized in that the diaphragm is provided with a boss part protruding upward from the middle part, the diaphragm press is provided with a concave part opening downward, the boss part engages with the concave part, the boss part has a circular truncated cone shape widening downward, a first corner part between the side surface and upper surface of the circular-truncated-cone-shaped boss part is formed into a chamfered R shape, the upper surface of the boss part and a bottom surface of the concave part are firmly bonded together during assembly, and a clearance between the diaphragm and the diaphragm press is provided around the boss part. |
