High temperature and high pressure cut-off valve are designed for thermal power plants, petrochemical industries, metallurgy, and other applications involving high-temperature and high-pressure water, steam, oil, or superheated steam pipes. They serve to cut off or connect the medium. 1. The valve features a self-tightening seal structure for enhanced sealing performance. 2. The disc and seat sealing surfaces are coated with vertical cobalt-based hard alloy spray welding, providing superior wear resistance, high temperature resistance, corrosion resistance, and abrasion resistance. 3. The stem is forged as a single piece, and undergoes quenching, tempering, and surface nitriding treatments, resulting in excellent corrosion and abrasion resistance. 4. The stuffing box has a well-designed depth with reliable packing and corrosion inhibitors for dependable sealing.