The diaphragm valve is a stop valve that uses the diaphragm as the opening and closing part to close the flow channel, cut off the fluid, and separate the inner cavity of the valve body and the inner cavity of the valve cover. The diaphragm is commonly made of elastic, corrosion-resistant, non-permeable materials such as rubber and plastic. The valve body is made of plastic, fiberglass, ceramic or metal lined material. Simple structure, good sealing and anti-corrosion performance, low fluid resistance. Used for low pressure, low temperature, corrosive and containing suspended material media