Top-mounted metal seal direct buried valve; is a kind of easy installation, on-line maintenance of the top-mounted metal seal butterfly valve installation. When the Wenzhou valve needs maintenance, without removing it from the pipeline, as long as little time to open the lid will be able to even the valve stem with a butterfly valve from the body cavity sealed butterfly valve installed for removal and repair work, so that maintenance becomes more simple Convenience. At present, the domestic and foreign production of hard-sealing butterfly valve butterfly plate side-mounted; in the process of installation of the butterfly valve in the event of failure need repair; must close the pipeline of media, the entire valve removed from the pipeline in order to install the metal seal butterfly valve Maintenance, maintenance of butterfly valve installation is difficult, the metal seal butterfly valve installation takes a long time, and the metal seal butterfly valve installation of the normal operation of the pipeline system; so professional design and development of top-mounted metal seal butterfly valve installed in the pipeline of Guangdong FRP Under the ball valve, you can easily remove the valve body.