The choice of gasket material mainly depends on the following three factors: temperature, pressure, and medium. 1. Metal gasket material 1. Carbon steel: The recommended maximum working temperature does not exceed 538℃, especially when the medium is oxidizing. High-quality thin carbon steel plates are not suitable for use in equipment manufacturing inorganic acids, neutral or acid salt solutions. If carbon steel is exposed to stress, the equipment accident rate under hot water conditions is very high. Carbon steel gaskets are usually used for high-concentration acids and many alkaline solutions. The Brinell hardness is about 120.
2. 304 stainless steel 18-8 (chromium 18-20%, nickel 8-10%), the recommended maximum operating temperature does not exceed 760℃. In the temperature range of -196~538℃, stress corrosion and grain boundary corrosion are prone to occur. The Brinell hardness is 160.
3. The carbon content of 304L stainless steel does not exceed 0.03%. The recommended maximum operating temperature does not exceed 760°C. Corrosion resistance is similar to 304 stainless steel. The low carbon content reduces the precipitation of carbon from the crystal lattice, and the resistance to intergranular corrosion is higher than that of 304 stainless steel. The Brinell hardness is about 140.
4. 316 stainless steel 18-12 (chromium 18%, nickel 12%), about 2% molybdenum is added to 304 stainless steel.
When the temperature increases, its strength and corrosion resistance will increase. When the temperature increases, it has higher creep resistance than other ordinary stainless steels. The recommended maximum operating temperature does not exceed 760°C. The Brinell hardness is about 160.
5. The recommended maximum continuous working temperature of 316L stainless steel does not exceed 760℃~815℃. The carbon content does not exceed 316 stainless steel, which has better resistance to stress and grain boundary corrosion. The Brinell hardness is about 140.
6. 20 alloy 45% iron, 24% nickel, 20% chromium and a small amount of molybdenum and copper. The recommended maximum operating temperature does not exceed 760℃~815℃. It is especially suitable for manufacturing equipment resistant to corrosion by sulfuric acid, with a Brinell hardness of about 160.
7. Aluminum aluminum (content not less than 99%). Aluminum has excellent corrosion resistance and processing properties, and is suitable for manufacturing double-clamp gaskets. The Brinell hardness is about 35. It is recommended that the maximum continuous working temperature does not exceed 426°C.
8. The composition of red copper is close to pure copper, and it contains a small amount of silver to increase its continuous working temperature. It is recommended that the maximum continuous working temperature does not exceed 260°C. The Brinell hardness is about 80.
9. Brass (66% copper, 34% zinc) has good corrosion resistance under most working conditions, but it is not suitable for acetic acid, salt, and salt. It is recommended that the maximum continuous working temperature does not exceed 260°C. The Brinell hardness is about 58.
10. Hastelloy B-2 (26-30% molybdenum, 62% nickel and 4-6% iron). The recommended maximum operating temperature does not exceed 1093°C. It has excellent heat-resistant concentration corrosion performance. It also has excellent resistance to wet chloride corrosion, sulfuric acid, phosphoric acid and reducing salt solution corrosion performance. It has high strength under high temperature conditions. The Brinell hardness is about 230.
11. Hastelloy C-276 16-18% molybdenum, 13-17.5% chromium, 3.7-5.3% tungsten, 4. 5-7% iron, the rest are nickel). The recommended maximum operating temperature does not exceed 1093°C. Has excellent corrosion resistance. It has excellent corrosion resistance to various tried cold nitric acid or boiling nitric acid with a concentration of 70%, and has good resistance to sulfuric acid corrosion and excellent stress corrosion resistance. The Brinell hardness is about 210.
12. Inconel 600 nickel-based alloy (77% nickel, 15% chromium and 7% iron). The recommended maximum operating temperature does not exceed 1093°C. It has high strength under high temperature conditions and is usually used in equipment that needs to solve stress corrosion problems. Under low temperature conditions, it has excellent processing performance. The Brinell hardness is about 150.
13. Monel 400 (copper 30%, nickel, the recommended maximum continuous working temperature does not exceed 815℃. Except for strong oxidizing acid, it has excellent corrosion resistance to most acids and alkalis. Stress corrosion cracking is easy to occur in hydrofluoric acid, and medium. Therefore, it is not suitable for the above-mentioned media. It is widely used in manufacturing equipment. The Brinell hardness is about 120.
14. The recommended maximum working temperature of titanium does not exceed 1093°C. Under high temperature conditions, it has excellent corrosion resistance. It is well known that it is resistant to chlorine. Ion erosion has excellent resistance to nitric acid corrosion in a wide range of temperature and concentration. Titanium is rarely used in most alkaline solutions and is suitable for oxidation conditions. The Brinell hardness is about 216. 2. Non-metal Gasket material
1. Natural rubber NR has good corrosion resistance to weak acids and alkalis, salt and chloride solutions, and poor corrosion resistance to oils and solvents, so it is not recommended for ozone media. Recommended working temperature -57℃ ~93℃.
2. Chloroprene CR Chloroprene rubber is a kind of synthetic rubber, which is suitable for the corrosion of acid, alkali and salt solution with moderate corrosion. It has good corrosion resistance to commercial oil and fuel. But in strong Oxidizing acids, aromatic hydrocarbons and chlorinated hydrocarbons have poor corrosion resistance. The recommended operating temperature is -51°C~121°C.
3. Butadiene rubber NBR Butadiene rubber is a synthetic rubber, suitable for a wide temperature range It has good corrosion resistance to oils, solvents, aromatic hydrocarbons, alkaline hydrocarbons, petroleum and natural gas. It has good corrosion resistance to hydroxides, salts and near neutral acids. But in strong oxidizing media, The corrosion resistance of chlorinated hydrocarbons, ketones and lipids is poor, and the recommended working temperature is 51℃~121℃.
4. Fluorine rubber is suitable for oil, fuel, chloride solution, aromatic hydrocarbons and lipid hydrocarbons. Strong acid has good corrosion resistance, but it is not suitable for amines, lipids, ketones and steam. The recommended working temperature is -40℃~232℃. Chlorosulfonylated polyethylene synthetic rubber has good corrosion resistance to acid, alkali and salt solutions, and is not affected by climate, light, ozone, and commercial fuels (such as diesel and etc.). It does not apply to aromatic hydrocarbons, chlorinated hydrocarbons, chromic acid and nitric acid. The recommended working temperature is -45℃~135℃.
6. Silicone rubber has good corrosion resistance to hot air. Silicone rubber is not affected by sunlight and ozone. But it does not apply to steam, ketones, aromatic hydrocarbons and lipid hydrocarbons.
7. Ethylene-propylene rubber has good corrosion resistance to strong acids, strong alkalis, salts and chloride solutions. But it does not apply to oils, solvents, aromatic hydrocarbons and hydrocarbons. The recommended working temperature is -57℃~176.
8. Graphite This material does not contain resin or inorganic substances, all graphite materials, can be divided into metal doped or not doped with metal elements graphite materials. The material can be bonded to make pipe gaskets with a diameter of more than 600MM. It has excellent corrosion resistance to many acids, alkalis, salts and organic compounds and heat transfer solutions, even high temperature solutions. It cannot be melted, but it will sublime when it exceeds 3316℃. Under high temperature conditions, the material should be used with caution in strong oxidizing media. In addition to being used for gaskets, this material can also be used to make non-metallic wound tapes in fillers and spiral wound gaskets.
9. Ceramic fiber, ceramic fiber formed on the strip is an excellent gasket material suitable for high temperature and low pressure working conditions and light flange conditions. The recommended working temperature is 1093°C. It can be used to make non-metallic spiral wound tapes in spiral wound gaskets.
10. PTFE 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, it has excellent corrosion resistance to chemicals, solvents, hydroxides and acids. PTFE material can be filled with glass, the purpose of which is to reduce the cold flow and creep properties of PTFE. Sealing gasket installation The material does not contain resin or inorganic substances, and can be divided into graphite materials doped with metal or not doped with metal elements. The material can be bonded to make pipe gaskets with a diameter of more than 600MM. It has excellent corrosion resistance to many acids, alkalis, salts and organic compounds and heat transfer solutions, even high temperature solutions. It cannot be melted, but it will sublime when it exceeds 3316℃. Under high temperature conditions, the material should be used with caution in strong oxidizing media. In addition to being used for gaskets, this material can also be used to make non-metallic wound tapes in fillers and spiral wound gaskets.
9. Ceramic fiber, ceramic fiber formed on the strip is an excellent gasket material suitable for high temperature and low pressure working conditions and light flange conditions. The recommended working temperature is 1093°C. It can be used to make non-metallic spiral wound tapes in spiral wound gaskets.
10. PTFE 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, it has excellent corrosion resistance to chemicals, solvents, hydroxides and acids. PTFE material can be filled with glass, the purpose of which is to reduce the cold flow and creep properties of PTFE. Sealing gasket installation The material does not contain resin or inorganic substances, and can be divided into graphite materials doped with metal or not doped with metal elements. The material can be bonded to make pipe gaskets with a diameter of more than 600MM. It has excellent corrosion resistance to many acids, alkalis, salts and organic compounds and heat transfer solutions, even high temperature solutions. It cannot be melted, but it will sublime when it exceeds 3316℃. Under high temperature conditions, the material should be used with caution in strong oxidizing media. In addition to being used for gaskets, this material can also be used to make non-metallic wound tapes in fillers and spiral wound gaskets. 9. Ceramic fiber, ceramic fiber formed on the strip is an excellent gasket material suitable for high temperature and low pressure working conditions and light flange conditions. The recommended working temperature is 1093°C. It can be used to make non-metallic spiral wound tapes in spiral wound gaskets. 10. PTFE 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, it has excellent corrosion resistance to chemicals, solvents, hydroxides and acids. PTFE material can be filled with glass, the purpose of which is to reduce the cold flow and creep properties of PTFE. Sealing gasket installation
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