The Q11F three-piece ball valve produced and sold by Huadian Pump Valve Company is an internal thread ball valve and a butt welded connection ball valve divided into integral type. The three-piece ball valve body casting adopts the advanced technology introduced from Taiwan, with reasonable structure and beautiful shape. The three-piece ball valve seat adopts elastic sealing structure, which is reliable sealing and easy to open and close. The valve stem adopts a bottom-mounted structure with an inverted seal, and the valve stem will not be flushed out when the valve cavity is abnormally boosted. The connection form is also butt welding (BW) and socket welding (SW), and can all come with international standard ISO bracket platform and locking device. The three-piece ball valve is set with a 90° switch positioning mechanism, which is locked as needed to prevent misoperation, and the driving mode: manual, electric, pneumatic.