The valve of this type is composed of body, bonnet, disc,stem and driving parts.
The opening and closing of the valve is accomplished by rotating the hand wheel, so as to bring the valve stem into axial movement, this causing the valve disc to work upward and downward . when the hand wheel is turned in clockwise direction, the valve disc goes down to cut off the flow passage of the medium.

The internal surface of valve body and the relevant surfaces of valve bonnet, valve disc and valve stem which contact with media are all lined with FEP plastic, therefore the present valve features an ideal performance of corrosion resistance. It finds application for different kinds of media, such as hydrochloric acid, sulfuric acid, hydrofluoric acid of various concentration, and aquaregia, nitric acid, different kinds of organic acids. strong alkalies, strong exidizing agents, or alternate concentric and dilute acids, alternate acid and alkali, various kinds of organic solvents and other strong corrosive media