Non-metallic gasket selection of raw materials
October 04, 2022
The choice of gasket material depends mainly on the following three factors: Temperature Pressure Medium 1. Natural rubber NR has good corrosion resistance to weak acids and alkalis, salts and chloride solutions, poor corrosion resistance to oils and solvents, and is not recommended for use in ozone media. Recommended working temperature -57 ℃ ~ 93 ℃. 2. Neoprene CR Neoprene is a synthetic rubber that is suitable for the corrosion of acids, alkalis and salt solutions that are resistant to moderate corrosion. Good resistance to commercial oils and fuels. But in the strong oxidizing acids, aromatic hydrocarbons and chlorinated hydrocarbons its corrosion resistance is poor. Recommended operating temperature -51 ℃ ~ 121 ℃. 3. Cyanuric NBR NBR is a synthetic rubber that has been shown to have good resistance to oils, solvents, aromatics, alkaline hydrocarbons, petroleum and natural gas over a wide temperature range. On the hydroxide, salt and nearly neutral acid has good corrosion resistance. However, strong oxidizing media, chlorinated hydrocarbons, ketones and lipids are poor corrosion resistance, the recommended operating temperature of 51 ℃ ~ 121 ℃. 4. Fluoroelastomers have good corrosion resistance to oils, fuels, chloride solutions, aromatics and aliphatic hydrocarbons and strong acids, but are not suitable for use in amines, lipids, ketones and vapors. The recommended operating temperature is -40 ° C ~ 232 ° C. 5. Chlorosulfonated polyethylene elastomers have good corrosion resistance to acids, alkalis and salt solutions and are not affected by climate, light, ozone, commercial fuels such as diesel and kerosene. But not suitable for aromatics, chlorinated hydrocarbons, chromic acid and nitric acid. Recommended working temperature -45 ℃ ~ 135 ℃. 6. Silicone rubber has good corrosion resistance to hot air. Silicone rubber is protected from sunlight and ozone. But not suitable for steam, ketones, aromatic hydrocarbons and lipid hydrocarbons. 7. Ethylene propylene rubber on the strong acid, alkali, salt and chloride solution has good corrosion resistance. But not suitable for oils, solvents, aromatic hydrocarbons and hydrocarbons. Recommended working temperature -57 ℃ ~ 176. 8. Graphite This material is free of resinous or inorganic all-graphite materials and can be divided into metal materials with or without metal elements. The material can be bonded to make pipe diameter more than 600MM gasket. For many acid, alkali, salt and organic compounds and heat transfer solution, even high temperature solution has very good corrosion resistance. It does not melt, but will sublimate beyond 3316 ° C. Under high temperature conditions, the material should be used with caution in highly oxidizing media. In addition to being used for gaskets, the material can also be used to make non-metallic tapes in packing and spiral wound gaskets. 9. Ceramic fiber, ceramic fiber formed on the strip is a good gasket material for high temperature and low pressure conditions and light flange conditions, the recommended operating temperature of 1093 ° C, can be made of non-metallic wound spiral wound gasket. 10. Teflon concentrates the advantages of most plastic gasket materials, including temperature resistance from -95 ° C to 232 ° C. In addition to free fluorine and alkali metals, chemicals, solvents, hydroxides and acids have excellent corrosion resistance. PTFE materials can be filled with glass, the purpose is to reduce the cold flow and creep of PTFE.
