The diaphragm valve is a special form of stop valve. Its opening and closing part is a diaphragm made of soft material, which separates the inner cavity of the valve body from the inner cavity of the valve cover and the drive part. The diaphragm valve is an elastic and perturbed diaphragm, which is bolted to the pressure member. The compression member is operated by the valve stem to move up and down. When the compression member rises, the diaphragm is lifted to form a channel. When the pressure member is downward, the diaphragm is pressed against the valve body weir (if it is a weir valve) or the bottom of the profile (if it is a straight-through type). The diaphragm valve is suitable for switching and throttling. The structural design of the diaphragm valve itself is particularly suitable for ultra-pure media or severely contaminated, very viscous liquids, gases, corrosive or inert media. When used in combination with control equipment, the diaphragm valve can replace other traditional control systems, especially for solid and easily contaminated inert media. The products are mainly used in biopharmaceuticals, food, industry; as well as industrial water treatment in the power, chemical, electroplating and other industries, and are also used in the production of semiconductor wafers.Diaphragm valves are particularly suitable for conveying corrosive and viscous fluids such as mud, food, medicine, and woven adhesives, because the operating mechanism of the diaphragm valve in the pipeline is not exposed to the conveying fluid, there is no pollution, and no packaging is required. The valve stem packing part is also unlikely to leak. The characteristics of the diaphragm valve are as follows: The most prominent feature of the diaphragm valve is that 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 disc and other components located above the diaphragm are not corroded by the medium, no packing and sealing structure are required, and no medium is generated. Leakage. The diaphragm made of soft seals such as rubber or plastic has better sealing performance. Since the diaphragm is a wearing part, it should be replaced regularly according to the characteristics of the medium. Limited by the diaphragm material, the diaphragm valve is suitable for low-pressure and relatively low-temperature applications. Diaphragm valves can be divided into six types according to the structural form: inner chamber type, direct current type, stop type, straight-through type, gate type and right-angle type; the connection form is usually flange connection; according to the drive mode, it can be divided into manual, electric and pneumatic three types, among which pneumatic drive is divided into normally open, normally closed and reciprocating three types.
