Due to the lack of concepts and equipment for valve maintenance and overhaul, only nuclear power plants in China can basically overhaul all valves during each shutdown and overhaul. Repairing a broken valve is a maintenance-free repair, which is not conducive to the safe operation of the entire set of equipment and the service life of the valve. The potential risk of emergency shutdown accidents is high, and the losses caused by this are also huge.

If the valve is repaired without maintenance, once it leaks, it is often already very seriously damaged, which not only increases the difficulty of repair, but also often even loses the possibility and value of repair. Therefore, for the well-organized and well-managed valve maintenance work, not only the relevant personnel should have corresponding awareness, but more importantly, preventive and maintenance measures, that is, regular inspection of the valve (for example, the sealing of the valve relative to the outside world, the sealing of the valve in the closed state, etc.). The key to preventive maintenance of valves is to repair the valve immediately when a leak is found in the valve, because the circulating medium can cause large-scale damage to the sealing surface in a short time even if the sealing surface is slightly damaged, resulting in expensive maintenance costs.