Gate valve for natural gas well mouth

The invention discloses a gate valve for a natural gas well mouth. The gate valve comprises a valve body and a valve plate. Flanges are arranged on the two sides of the valve body, a through runner isarranged in the middle of the valve body, a cavity is formed in the middle of the runner to be adopted as a valve cavity, the upper portion of the valve cavity runs through the valve body, the two parts, partitioned by the valve cavity, of the runner are adopted as an inlet runner and an outlet runner, the valve plate is of a rectangular structure and is installed in the valve cavity, one side makes contact with the valve cavity in the direction of the inlet runner, the other side makes contact with the valve cavity of the outlet runner, a valve rod is arranged above the valve plate, and a handle is installed at the upper end of the valve rod; a sealing packing is arranged at the position, penetrating out of the valve body, of the cavity and is tightly attached to the valve rod, a slidingsealing block is arranged at the position where the upper end of the valve plate makes contact with the valve rod, the two sides of the sliding sealing block are tightly attached to the valve cavity,a transverse sealing protrusion section is arranged below the valve plate, and the sealing protrusion section is of a semicircular structure; a plurality of metal protrusion sections are arranged atthe lower section of the valve cavity. By improving the structure of a conventional valve, blocking and sealing can be better achieved, and the safety effect is achieved.