High pressure gate valve with pressure seal bonnet, rising stem, outside screw & yoke, metal to metal seat, wedge disc with cover stellite as well as seat and back seat.Pressure seal gate valve normally used in the high pressure main streaming pipeline or high pressure bypass water feeding pipeline etc. The main function of BW gate valve is to cut off or cut on the medium controlled by electric actuator or handwheel. The sealing principle of wedge gate valve is sealing surface tight off under pressure and they are widely applicated in petrochmical, thermal power plant. Power station gate valve material can cover carbon steel, alloy steel, special steel, such as WCB,WC6,WC9,C5,C12, C12A, CrMoV etc.