Fluorine-lined diaphragm valves are a special form of shut-off valve that appeared in the 1920s. Its opening and closing member is a diaphragm made of soft material, which separates the valve body cavity from the bonnet inner cavity and the driving component, so it is called a diaphragm valve.
The most prominent feature is that the diaphragm separates the lower valve body cavity from the inner cavity of the upper valve cover, so that the valve stem, valve disc and other parts located above the diaphragm are not corroded by the medium, the packing sealing structure is omitted, and no leakage of the medium occurs. .
1. The diaphragm made of soft seal such as rubber or plastic has good sealing performance. Since the diaphragm is a consumable part, it should be replaced periodically depending on the characteristics of the medium.
2, limited by the diaphragm material, the diaphragm valve is suitable for low pressure and relatively low temperature.
3. Diaphragm valves can be divided into six types according to the structure: House type, direct current type, cut-off type, straight-through type, gate type and right angle type; the connection form is usually flange connection; according to the driving method, it can be divided into manual, electric and pneumatic. Three kinds, among which the pneumatic drive is divided into three types: Normally open, normally closed and reciprocating.
4. Generally not suitable for pipelines with temperatures above 60 °c and transporting organic solvents and strong oxidizing media, and should not be used in pipelines with higher pressure.