Forged steel fixed ball valve series all parts are forged, the overall structure of the valve is compact, small size, good steel, suitable for high pressure and large caliber pipeline selection, the valve seat uses spring interception active structure, and can be designed according to customer requirements into two-way import seal, one-way in and out at the same time seal, through the precise calculation of the pressure bearing cross-sectional area of the valve seat, to ensure high pressure conditions. The lower valve can be opened and closed with a cut-off valve; the use of the self-contained discharge valve can effectively ensure the safety of the valve when the valve body chamber accidentally boosts; the valve shaft adopts a blowout-proof protection structure, three-way sealing measures; bearings with low friction coefficient, the valve stem and the valve body have no contact, so that the valve can be opened and closed easily.