Valve oil seals can prevent oil from entering the intake and exhaust pipes, causing oil loss, preventing the mixture of gasoline and air, as well as exhaust gas leakage, and preventing engine oil from entering the combustion chamber. Valve oil seal is one of the important parts of the engine valve group, which comes into contact with gasoline and engine oil at high temperatures. Therefore, it is necessary to use materials with excellent heat and oil resistance, usually made of fluororubber.