Metal gasket material
1. Carbon steel
The maximum operating temperature is recommended not to exceed 538 ℃, especially when the medium is oxidizing. High quality thin carbon steel plate is not suitable for equipment used to manufacture inorganic acid, neutral or acid salt solution. If carbon steel is subjected to stress, the equipment accident rate under hot water condition is very high. Carbon steel gaskets are usually used for high concentrations of acid and many alkali solutions. Brinell hardness is about 120.
2.304 stainless steel
18-8 (chromium 18-20%, nickel 8-10%), and the recommended maximum operating temperature shall not exceed 760 ℃. In the temperature range of – 196 ~ 538 ℃, stress corrosion and grain boundary corrosion are easy to occur. Brinell hardness 160.
3.304l stainless steel
The carbon content shall not exceed 0.03%. The recommended maximum operating temperature shall not exceed 760 ℃. Corrosion resistance is similar to 304 stainless steel. The low carbon content reduces the precipitation of carbon from the lattice, and the grain boundary 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 in 304 stainless steel. When the temperature increases, its strength and corrosion resistance improve. When the temperature increases, it has higher creep resistance than other ordinary stainless steels. The recommended maximum operating temperature shall not exceed 760 ℃. Brinell hardness is about 160.
5.316l stainless steel
The recommended maximum continuous operating temperature shall not exceed 760 ℃ ~ 815 ℃. Compared with 316 stainless steel, it has better stress resistance and grain boundary 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 operating temperature shall not exceed 760 ℃ ~ 815 ℃. It is especially suitable for manufacturing equipment resistant to sulfuric acid corrosion, with Brinell hardness of about 160.
7. Aluminum
Aluminum (content not less than 99%). Aluminum has excellent corrosion resistance and processability, which is suitable for manufacturing double clip gaskets. Brinell hardness is about 35. The recommended maximum continuous operating temperature shall not exceed 426 ℃.
8. Red copper
The composition of red copper is close to pure copper, which contains a small amount of silver to increase its continuous working temperature. It is recommended that the maximum continuous working temperature should not exceed 260 ℃. Brinell hardness is about 80.
9. Brass
(copper 66%, zinc 34%), it has good corrosion resistance under most working conditions, but it is not suitable for acetic acid, ammonia, salt and acetylene. It is recommended that the maximum continuous working temperature should not exceed 260 ℃. Brinell hardness is about 58.
10. Hastelloy B-2
(26-30% molybdenum, 62% nickel and 4-6% iron). The recommended maximum operating temperature shall not exceed 1093 ℃. It has excellent heat resistance and hydrochloric acid corrosion performance. It also has excellent resistance to wet hydrogen chloride gas corrosion, sulfuric acid, phosphoric acid and reducing salt solution corrosion. It has high strength at high temperature. 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 shall not exceed 1093 ℃. It has excellent corrosion resistance. It has excellent corrosion resistance to cold nitric acid or boiling nitric acid with a concentration of 70%, good corrosion resistance to hydrochloric acid and sulfuric acid and excellent stress corrosion resistance. Brinell hardness is about 210.
12. Inconel 600
Nickel base alloys (77% nickel, 15% chromium and 7% iron). The recommended maximum operating temperature shall not exceed 1093 ℃. It has high strength under high temperature conditions and is usually used for equipment to solve stress corrosion problems. At low temperature, it has excellent same processing properties. Brinell hardness is about 150.
13. Monel 400
(recommended maximum continuous operating temperature of copper 30% and nickel shall not exceed 815 ℃. Except for strong oxidizing acids, it has excellent corrosion resistance to most acids and bases. It is easy to produce stress corrosion cracks 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. Brinell hardness is about 120.
14. Titanium
The recommended maximum operating temperature is no more than 1093 ℃. It has excellent corrosion resistance under high temperature conditions. It is well known that it is resistant to chloride ion corrosion and has excellent nitric acid corrosion resistance in a wide temperature and concentration range. Titanium is rarely used in most alkali solutions and is suitable for oxidation conditions. Brinell hardness is about 216.
Non metallic gasket material
1. Natural Rubber NR
It has good corrosion resistance to weak acid, alkali, salt and chloride solutions, but poor corrosion resistance to oil and solvent. It is not recommended to be used in ozone medium. The recommended operating temperature is – 57 ℃ ~ 93 ℃.
2. Neoprene Cr
Neoprene is a kind of synthetic rubber, which is suitable for medium corrosion resistance in acid, alkali and salt solutions. It has good corrosion resistance to commercial oils and fuels. However, the corrosion resistance of strong oxidizing acids, aromatic hydrocarbons and chlorinated hydrocarbons is poor. The recommended operating temperature is – 51 ℃ ~ 121 ℃.
3. Nitrile butadiene rubber NBR
Cyano butadiene rubber is a kind of synthetic rubber, which is suitable for good corrosion resistance to oil, solvent, aromatic hydrocarbon, alkaline hydrocarbon, oil and natural gas in a wide temperature range. It has good corrosion resistance to hydroxide, salt and near neutral acid. However, in strong oxidizing medium, chlorinated hydrocarbons, ketones and lipids, their corrosion resistance is poor. The recommended working temperature is 51 ℃ ~ 121 ℃.
4. Fluororubber
It has good corrosion resistance to oil, fuel, chloride solution, aromatic and lipid hydrocarbons and strong acids, but it is not suitable for amines, lipids, ketones and steam. The recommended working temperature is – 40 ℃ ~ 232 ℃.
5. Chlorosulfonated polyethylene synthetic rubber
It 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 kerosene). However, it is not suitable for aromatic hydrocarbons, chlorinated hydrocarbons, chromic acid and nitric acid. The recommended operating 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. Ethylene propylene rubber
It has good corrosion resistance to strong acid, alkali, salt and chloride solutions. However, it is not suitable for oils, solvents, aromatic hydrocarbons and hydrocarbons. The recommended operating temperature is – 57 ℃ ~ 176 ℃.
8. Graphite
The material is an all graphite material without resin or inorganic matter, which can be divided into graphite materials with or without metal elements. The material can be bonded to produce pipe gaskets with a diameter of more than 600mm. It has excellent corrosion resistance to many acids, bases, salts, organic compounds, heat transfer solutions and even high temperature solutions. It cannot melt, but will sublimate above 3316 ℃. Under high temperature conditions, the material should be used carefully in strong oxidizing medium. In addition to gaskets, the material can also be used to make non-metallic winding tapes in fillers and spiral wound gaskets.
9. Ceramic fiber, ceramic fiber formed on strip
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 the non-metallic winding tape in the wound gasket can be made.
10 polytetrafluoroethylene
It integrates the advantages of most plastic gasket materials, including temperature resistance from – 95 ℃ ~ 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 to reduce the cold fluidity and creep of PTFE.
Post time: Nov-02-2021
