Metal gasket materials
1. Carbon steel
The recommended maximum operating temperature is not more than 538℃, especially when the medium oxidizes. High-quality thin carbon steel plates are not suitable for equipment used to manufacture inorganic acids, neutral or acidic salt solutions. If carbon steel is subjected to stress, the accident rate of equipment used under hot water working conditions is very high. Carbon steel gaskets are usually used for high-concentration acids and many alkaline solutions. Brinell hardness is about 120.
2. 304 stainless steel
18-8 (chromium 18-20%, nickel 8-10%), the recommended maximum operating temperature is not more than 760℃. In the temperature range of -196~538℃, stress corrosion and intergranular corrosion are prone to occur. Brinell hardness 160.
3. 304L stainless steel
The carbon content does not exceed 0.03%. The recommended maximum operating temperature is not more than 760℃. The corrosion resistance is similar to that of 304 stainless steel. The low carbon content reduces the precipitation of carbon from the lattice, and the intergranular corrosion resistance is higher than that of 304 stainless steel. Brinell hardness is about 140.
4.316 stainless steel
18-12 (chromium 18%, nickel 12%), add about 2% molybdenum to 304 stainless steel, when the temperature increases, its strength and corrosion resistance increase. When the temperature increases, it has higher creep resistance than other ordinary stainless steels. The recommended maximum working temperature does not exceed 760℃. Brinell hardness is about 160.
5.316L stainless steel
The recommended maximum continuous working temperature does not exceed 760℃~815℃. The carbon content does not exceed 316 stainless steel, which has better stress resistance and intergranular corrosion resistance. 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 working temperature does not exceed 760℃~815℃. It is especially suitable for manufacturing equipment resistant to sulfuric acid corrosion, 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. The recommended maximum continuous working temperature is not more than 426℃.
8. Copper
The composition of copper is close to pure copper, and it contains a trace amount of silver to increase its continuous working temperature. The recommended maximum continuous working temperature is not more than 260℃. The Brinell hardness is about 80.
9. Brass
(66% copper, 34% zinc), has good corrosion resistance under most working conditions, but is not suitable for acetic acid, ammonia, salt, and acetylene. The recommended maximum continuous working temperature is not more than 260℃. The Brinell hardness is about 58.
10. Hastelloy B-2
(26-30% molybdenum, 62% nickel, and 4-6% iron). The recommended maximum working temperature is not more than 1093℃. It has excellent resistance to hot concentrated hydrochloric acid corrosion. It also has excellent resistance to wet hydrogen chloride gas corrosion, sulfuric acid, phosphoric acid, and reducing salt solution corrosion. 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, and the rest are nickel). The recommended maximum operating temperature does not exceed 1093°C. It has excellent corrosion resistance. It has excellent corrosion resistance to various cold nitric acid or boiling nitric acid with a concentration of 70%, good resistance to hydrochloric acid and sulfuric acid corrosion, and excellent resistance to stress corrosion. 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
(30% copper, nickel) The recommended maximum continuous operating temperature does not exceed 815℃. It has excellent corrosion resistance to most acids and alkalis except strong oxidizing acids. Stress corrosion cracking is easy to occur in fluoric acid, mercuric chloride, and mercury media, so it is not suitable for the above media. It is widely used in equipment for manufacturing hydrofluoric acid. The Brinell hardness is about 120.
14. Titanium
The recommended maximum operating temperature does not exceed 1093℃. Under high-temperature conditions, it has excellent corrosion resistance. It is well known that it is resistant to chloride ion corrosion and has excellent resistance to nitric acid corrosion in a wide temperature and concentration range. Titanium is rarely used in most alkaline solutions and is suitable for oxidizing working conditions. The Brinell hardness is about 216.
Non-metallic gasket materials
1. Natural rubber NR
It 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 ozone media. The recommended working temperature is -57℃~93℃.
2. Neoprene CR
Neoprene is a synthetic rubber that is suitable for corrosion resistance to moderately corrosive acids, alkalis, and salt solutions. It has good corrosion resistance to commercial oils and fuels. However, its corrosion resistance is poor in strong oxidizing acids, aromatic hydrocarbons, and chlorinated hydrocarbons. The recommended working temperature is -51℃~121℃.
3. Nitrile rubber NBR
Nitrile rubber is a synthetic rubber that is suitable for good corrosion resistance to oils, solvents, aromatic hydrocarbons, alkaline hydrocarbons, petroleum, and natural gas in a wide temperature range. It has good corrosion resistance to hydroxides, salts, and nearly neutral acids. However, its corrosion resistance is poor in strong oxidizing media, chlorinated hydrocarbons, ketones, and lipids. The recommended working temperature is 51℃~121℃.
4. Fluororubber
It has good corrosion resistance to oils, fuels, chloride solutions, aromatic and lipid hydrocarbons, and strong acids, but is not suitable for amines, lipids, ketones, and steam. The recommended working temperature is -40℃~232℃.
5. Chlorosulfonylated polyethylene synthetic rubber It has good corrosion resistance to acid, alkali, and salt solutions, and is not affected by climate, light, ozone, commercial fuels (such as diesel and kerosene, etc.). However, it is not suitable for aromatic hydrocarbons, chlorinated hydrocarbons, chromic acid, and nitric acid. The recommended working temperature is -45℃~135℃.
6. Silicone rubber
It has good corrosion resistance to hot air. Silicone rubber is not affected by sunlight and ozone. However, it is not suitable for steam, ketones, aromatic hydrocarbons, and lipid hydrocarbons.
7. EPDM rubber
It has good corrosion resistance to strong acids, strong alkalis, salts, and chloride solutions. However, it is not suitable for oils, solvents, aromatic hydrocarbons, and hydrocarbons. The recommended working temperature is -57℃~176.
8. Graphite
This material is a full graphite material without resin or inorganic matter, which can be divided into graphite materials with or without metal elements. This material can be bonded and can even manufacture pipe gaskets with a diameter of more than 600MM. It has very excellent corrosion resistance to many acids, alkalis, salts, and organic compounds and heat transfer solutions, even high-temperature solutions. It cannot melt but 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, the material can also be used to make fillers and non-metallic winding tapes in spiral-wound gaskets.
9. Ceramic fiber, ceramic fiber molded in strips
It is an excellent gasket material suitable for high-temperature and low-pressure conditions and light flange conditions. The recommended working temperature is 1093℃, and it can be used to make non-metallic winding tapes in spiral wound gaskets.
10 Polytetrafluoroethylene It concentrates on the advantages of most plastic gasket materials, including temperature resistance from -95℃ to 232℃. 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.
