... API SPEC 6A. 2.Driving mode:manual,gear drive,hydraulic 3.Gate structure:integral,expanded. PLATE GATE VALVE Feature in design :Comply with ... type:Flange,thread,collar and butt welding,Driving mode:Manual,gear drive and hydraulic,Gate structure:Integral,expanded,The sealing face of ... gate and seat is overlaying –welded with hard alloy with erosion ...