The valve is a control component in the pipeline fluid conveying system. It is used to change the passage section and the flow direction of the medium. It has the functions of diversion, cutoff, throttling, check, diversion, or overflow pressure relief. There are two reasons for the damage to the sealing surface: man-made damage and natural damage. Man-made damage is caused by factors such as poor manufacturing, improper selection of materials, improper installation, poor use, and ineffective maintenance. Natural damage is the wear of the valve under normal working conditions and the damage caused by the inevitable corrosion and erosion of the sealing surface of the medium.