Pressure-operated control valve

摘要

A ball valve and a valve shaft are in a valve chamber. The ball valve opens and closes a valve port. A coil spring arranged in a spring chamber pushes the valve shaft against a diaphragm via a spring bracket of the valve shaft. A cone portion and a flat portion (or a concave portion) inside the cone portion are on the diaphragm. A diaphragm-side end face of the valve shaft is larger in diameter than the flat portion of the diaphragm. When the diaphragm is initially deformed, a boundary portion interposed between the cone portion and the flat portion abuts on the diaphragm-side end face.