High temperature and high pressure ball valves have the following advantages: 1. The fluid resistance is small, and its resistance coefficient is equal to the pipe length of the same length. 2. The structure is simple, small in size and light in weight. 3. It is compact and reliable. At present, the sealing surface material of the ball valve is widely used in plastic and has good sealing performance. It has also been widely used in vacuum systems. 4. The operation is convenient, the opening and closing is rapid, and the rotation is 90° from full opening to full closing, which is convenient for long-distance control. 5. The maintenance is convenient, the ball valve has a simple structure, and the sealing ring is generally movable, and the disassembly and replacement are relatively convenient. 6. When fully open or fully closed, the sealing surface of the ball and the valve seat is isolated from the medium, and the medium does not cause erosion of the sealing surface of the valve. 7. Wide range of applications, from small to a few millimeters, up to a few meters, from high vacuum to high pressure can be applied. When the ball is rotated 90 degrees, all the spheres should appear at the entrance and exit, thus cutting off the flow.