Diaphragm valve

Abstract

The objective of this invention is to suppress the generation of particles from the diaphragm caused by the sliding of the diaphragm and valve body during diaphragm deformation. The diaphragm valve includes: a valve body 13 having a valve chamber 19 and a valve seat 21 formed around an opening from an inlet flow path 25 to the valve chamber 19; a diaphragm 15; and a drive unit having a diaphragm pressing portion 57. The diaphragm 15 includes: a valve body portion 51 that contacts / separates from the valve seat 21; a membrane portion 53; an outer peripheral portion 55; and an annular bridging portion 59 having higher rigidity than the membrane portion 53 and connecting the outer peripheral portion 55 and the membrane portion 53. The outer peripheral portion 55 includes a flange portion 55a and a cylindrical collar portion 55b. The diaphragm pressing portion 57 has a protrusion 57a ​​protruding toward the valve seat 21. The protrusion 57a ​​clamps at least a portion of the collar portion 55b of the diaphragm between the outer peripheral surface of the protrusion 57a ​​and the inner peripheral surface of the valve chamber 19.

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