Diaphragm, diaphragm valve, and method of manufacturing diaphragm

摘要

Provided are a diaphragm, a diaphragm valve, and a method of manufacturing a diaphragm capable of increasing a flow rate (Cv value) of gas without degrading long-term durability even when a displacement amount is increased. A diaphragm (1) has an outer diameter Phi of 10 to 35 mm and includes a dome portion (1D) in a dome shape and a flange portion (1T) formed continuously at a peripheral edge of the dome portion (1D) via a boundary portion (1K), the boundary portion (1K) has a radius of curvature R of 0.6 mm or more on a convex side of the dome portion (1D), and the diaphragm is formed of a cobalt-based super-alloy.