The sealing principle of the diaphragm valve is to press down the diaphragm or the diaphragm assembly and the channel of the weir-type lining valve body or the straight-through lining valve body by the downward movement of the operating mechanism, so as to achieve sealing. The size of the sealing specific pressure is realized by the downward pressure of the closing part. Since the valve body can be lined with various soft materials, such as rubber or PTFE; the diaphragm is also made of soft materials, such as PTFE lined with rubber or synthetic rubber, so it can be achieved with a small sealing force. Completely sealed.
Diaphragm valves have only three main components: body, diaphragm and bonnet assembly. The diaphragm separates the inner cavity of the lower valve body from the inner cavity of the upper valve cover, so that the valve stem, valve stem nut, valve disc, pneumatic control mechanism, electric control mechanism and other components located above the diaphragm are not in contact with the medium, and no medium will be generated. External leakage, eliminating the need for the sealing structure of the stuffing box.
