1. Rubber valve: Because the valve is an unavoidable aging problem of the rubber material, the valve body will gradually crack, deform and lose elasticity. When the vehicle is running, the rubber valve will also sway back and forth with the centrifugal force, which will further promote the aging of the rubber. Generally speaking, the life of the rubber valve is 3-4 years, which is similar to the life of the tire. Therefore, the rubber valve should be replaced when changing the tire;

2. Metal valve: In order to avoid the aging problem of rubber valve, metal valve is gradually appearing on the market, and steel valve is one of them. Due to material changes, the price of steel valve is much higher than that of rubber valve. The service life of steel valve is two to three times that of rubber valve. This is mainly due to its metal material is not easy to be oxidized. The metal valve also has better air tightness. Of course, the price of metal valve is much higher than that of rubber valve