The brighter the end face of the seal, the greater the bearing capacity, especially the end face is more important than the pressure of the seal. The bearing area varies greatly with different roughness of seal end face. Some people only install and use the seal end face after grinding, as can be seen from Table 1, at this time only 40% of the bearing area, obviously the end face pressure increased by 1.5 times. If the end specific pressure is 0.4MPa, it will actually reach 1.0MPa. For the friction pair of tungsten carbide ring and graphite pair, due to the difference in hardness and elasticity, it is possible to heat or even crack at the high point of the surface of the tungsten carbide ring due to excessive local pressure, and the surface of the graphite ring will grind out fine ring grooves. The vibration of the pump and the different hearts of the dynamic and static rings will exacerbate this wear. The worn graphite exists between the end faces of the seal, forming abrasive wear, making the wear more intense, and the leaked medium contains graphite particles and appears black. After many seals are installed, this phenomenon occurs when the pump is opened, and the reason is that the seal end face is not smooth or uneven.