The opening and closing component of the bellows sealed gate valve is a plug shaped valve disc, with a flat or conical sealing surface, and the valve disc moves linearly along the centerline of the fluid. The movement form of the valve stem includes a lifting rod type (the valve stem is lifted and lowered without the handwheel lifting), as well as a lifting rotating rod type (the handwheel rotates and lifts together with the valve stem, and the nut is set on the valve body). Bellows gate valves are only suitable for fully open and fully closed, and are not allowed to be adjusted or throttled. Bellows sealed gate valves should generally be installed horizontally in pipelines.