1. Valve sealing is a general technology necessary in various industrial fields. Not only construction, petrochemical, shipbuilding, machinery manufacturing, energy, transportation, environmental protection and other industries are inseparable from sealing technology, but cutting-edge industries such as aviation and aerospace are also related to sealing technology. Technology is closely related. Valve sealing is applied in a wide range of fields, and there are sealing problems in all devices involving fluid storage, transportation, and energy conversion.
2. The importance of valve sealing technology
The consequences of valve sealing failure are very serious. In the lightest cases, "running, leaking, dripping, and leakage" will cause waste of energy and resources. In severe cases, the operation will fail, and even fire, explosion, environmental pollution and other consequences will endanger personal safety!
3. Development of valve sealing materials
With the development of science and technology, the working conditions of the valve sealing structure are more stringent. As the temperature, pressure and corrosion of valve sealing fluid are greatly increased, traditional sealing materials such as felt, hemp silk, asbestos silk, putty, etc. can no longer meet the requirements of valve use, and are gradually replaced by rubber and other synthetic materials. Synthetic materials such as rubber are generally high-molecular polymers, and functional groups with different characteristics (such as chlorine, fluorine, cyano, vinyl, isocyanate, hydroxyl, carboxyl, alkoxy, etc.) on the macromolecular chain become active cross-linking point. Under the action of catalysts, vulcanizing agents, or high-temperature, high-energy rays, macromolecules change from linear structures and branched structures to spatial network structures. This process is called vulcanization. After vulcanization of rubber or other synthetic materials, the macromolecules lose their original fluidity, which is called an elastomer with high elastic deformation.
4. Commonly used rubber and synthetic materials for valve seals are: natural rubber, styrene-butadiene rubber, neoprene, nitrile rubber, ethylene-propylene rubber, butyl rubber, polyurethane rubber, acrylic rubber, fluororubber, silicone rubber, etc.
