Diaphragm valve is a special form of shut-off valve. It first appeared in the 1920s. The opening and closing member of it is a piece of diaphragm made of soft materials, which separates the valve body cavity and the valve cover cavity and the actuating components, hence the name diaphragm valve.
The features of sanitary diaphragm valve are as follows:
The most prominent feature is that the diaphragm separates the cavity of lower valve body and the cavity of upper valve cover, so that parts above the diaphragm such as valve stem and valve flap won’t be affected by media corrosion. This eliminates the stuffing sealing structure and will not cause media leakage.
Diaphragm that is made of soft sealing such as rubber or plastics has a good sealing effect. As diaphragm is prone to damage, it should be regularly replaced depending on the media characteristics.
Due to limitations of diaphragm materials, diaphragm valves are suitable for occasions where the pressure is low and the temperature is relatively low.