Steel plug is the plug hole with the body as a hoist parts, around the axis perpendicular to the channel rotation, by rotating the valve to open and close the channel. Plug body with the valve stem rotation, in order to achieve switching. Plug the plug body mostly cone (also cylinder), and the body of the conical bore sealing surface with the composition.

steel valve is to use one of the first valve, the structure is simple, fast switching, fluid resistance, the ball valve is also evolved from the plug. Small no filler plug, also known as