Scope of application of Sealing Gasket

Gaskets are mechanical seals between two objects, usually used to prevent pressure, corrosion, and natural thermal expansion and cold contraction leakage between two objects. Because the machining surface cannot be perfect, the irregularities can be filled with gaskets. Gaskets are usually made of sheet materials, such as pad paper, rubber, silicone rubber, metal, cork, felt, neoprene, nitrile rubber, glass fiber, or plastic polymers (such as PTFE). Gaskets for a specific application may contain asbestos.

Scope of application: The material of the gasket mainly depends on the following three factors: temperature and pressure medium.  

.Metal gasket material: 1. Carbon steel: the recommended maximum working temperature is not to exceed 538℃, especially when the medium is oxidized. High quality thin carbon steel plate is also not suitable for manufacturing inorganic acid, neutral or acid salt solution. If carbon steel is under stress, the equipment accident rate for hot water conditions is very high. Carbon steel gaskets are commonly used in high concentrations of acid and many alkali solutions. Brucell hardness is about 120.

2. 304 Stainless steel 18-8 (chromium 18-20%, nickel 8-10%), with a recommended maximum operating temperature of not exceeding 760℃. Stress corrosion and crystal boundary corrosion are prone in the temperature-196~538℃ range. Brinell hardness of 160. 

3. The carbon content of 304L stainless steel is not more than 0. 03%. The recommended maximum operating temperature is not exceed 760℃. Corrosion resistance is similar to a 304 stainless steel performance. Low carbon content reduces the precipitation of carbon from the lattice, and the crystal boundary corrosion resistance is higher than 304 stainless steel. Brucell hardness is about 140.

4 . 316 Stainless Steel 18-12 (chromium 18%, nickel 12%), adding about 2% molybdenum in 304 stainless steel, when the temperature increases its strength and corrosion resistance increases. Temperature increases higher creep resistance than other ordinary stainless steel. The recommended maximum operating temperature is not exceed 760℃. Brucell hardness is about 160.

5. The maximum continuous working temperature shall not exceed 760℃ ~815℃. Carbon content does not exceed better stress resistance and crystal boundary corrosion relative to 316 stainless steel. Brucell hardness is about 140.

 6. 20 Alloy 45% iron, 24% nickel, 20% chromium, and small amounts of molybdenum and copper. The recommended maximum operating temperature does not exceed 760℃ ~815℃. Especially suitable for the manufacture of sulfuric acid corrosion resistant equipment, brucell hardness of about 160.

7. Aluminum and aluminum (not less than 99% content). Aluminum has excellent corrosion resistance and machining properties for making double clip gaskets. Brucell hardness is about 35. The recommended maximum continuous operating temperature does not exceed 426℃.

8. Copper copper is close to pure copper, which contains trace amounts of silver to increase its continuous operating temperature. The recommended maximum continuous operating temperature is not exceeding 260℃. Brucell hardness is about 80.

9. Brass (copper 66%, zinc 34%), with good corrosion resistance under most working conditions, but not suitable for acetic acid, ammonia, salt and acetylene. The recommended maximum continuous operating temperature is not exceeding 260℃. Brucell hardness is about 58.

10. Kazakh B-2 (26-30% molybdenum, 62% nickel, and 4-6% iron). The recommended maximum operating temperature is not exceed 1093℃. It has excellent heat resistance concentration and hydrochloric acid corrosion resistance. It also has excellent resistance to wet hydrogen chloride gas corrosion, sulfuric acid, phosphoric acid and reducing salt solution corrosion properties. High intensity at high temperatures. Brucell hardness is about 230.

11. 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 is not exceed 1093℃. Excellent corrosion resistance. It has excellent corrosion resistance to various tried cold nitric acid or boiling nitric acid with a concentration of 70%, with good hydrochloric acid and sulfuric acid corrosion resistance and excellent stress corrosion resistance. The Brucell hardness is about 210.

 12. Inconel 600 Nickel-based alloy (77% nickel, 15% chromium, and 7% iron). The recommended maximum operating temperature is not exceed 1093℃. With high strength at high temperature conditions, usually used for equipment needed to solve stress corrosion problems. Under low temperature conditions, it has excellent coprocessing performance. Brucell hardness is about 150.

13. Monnaire 400 (copper, 30%, nickel, and the recommended maximum continuous working temperature is not exceeding 815℃. It has excellent corrosion resistance to most acids and bases. In fluoric acid, mercury chloride, mercury medium, therefore, is not suitable for the above medium. Equipment that is widely used in the manufacture of hydrofluoric acid. Brucell hardness is about 120.

14. Titanium.

The recommended maximum operating temperature is not exceed 1093℃. Under high temperature conditions, it has excellent corrosion resistance. It is well known to be resistant to chloride ions and has excellent nitric acid corrosion resistance in wide temperature and concentration ranges. Titanium is rarely used in most alkali solutions, suitable for oxidation conditions. Brucell hardness is about 216.

Non-metallic gasket material: 1. Natural rubber NR has good corrosion resistance to weak acid and alkali, salt and chloride solutions, and has poor corrosion resistance to oil and solvent, and is not recommended for ozone media. Recommended operating temperature-57℃ ~93℃.

 2. Neoprene CR neoprene is a synthetic rubber, suitable for moderate corrosion resistance of acid, alkali and salt solutions of corrosion. It has good corrosion resistance to commercial oil and fuel. However, the corrosion resistance of highly oxidized acids, aromatic hydrocarbons and chloride hydrocarbons is poor. Recommended operating temperature-51℃ ~121℃.

3.NBR Tinocyanrubber is a synthetic rubber suitable to provide good corrosion resistance to oil, solvents, aromatic hydrocarbons, alkaline hydrocarbons, petroleum and natural gas over a wide temperature range. It has good corrosion resistance to hydroxide, salts and nearly neutral acids. However, the corrosion resistance of strong oxidation media, hydrocarbon chloride, ketones and lipids is poor, and the recommended working temperature is 51℃ ~121℃.

4.Fluorine rubber fluorine rubber rubber is made of binary and ternary fluorogenic glue filling compound, vulcanizing agent by mixing. In addition to its excellent heat resistance, medium resistance, and good physical and mechanical properties, it also has low compression permanent deformation, good elasticity and super long service life. Fluorous rubber has outstanding heat resistance (200~250℃), oil resistance, can be used to make cylinder sleeve seals, tape and rotating lip sealing rings, can significantly improve the service time. Recommended operating temperature-40℃ ~232℃.

5.Chlorosulfonyylated polyethylene synthetic rubber has good corrosion resistance to acid, alkali and salt solutions, while not affected by climate, light, ozone, commercial fuels (such as diesel and kerosene, etc.). But it is not suitable for aromatic hydrocarbons, chloride hydrocarbons, chromic acid and nitric acid. Recommended operating temperature-45℃ ~135℃.

6.Silicone rubber silicone rubber has outstanding high and low temperature resistance, can be long-term use at 150℃ without performance change, can be continuously used for 10000 hours at 200℃, in-70~260℃ working temperature range can maintain its unique elasticity and ozone resistance, weather resistance, suitable for making gasneeded in thermal mechanism, such as sealing liner, valve pad, oil seal (suitable for water medium), special silicone rubber can make oil seal.

7.Ethylpropylene rubber has good corrosion resistance to strong acid, strong alkali, salt and chloride solutions. But it is not suitable for use in oils, solvents, aromatic hydrocarbons, and hydrocarbons. Recommended operating temperature-57℃ ~176.

8. Graphite This material does not contain resin or inorganic full graphite material, can be divided into metal mixed with metal or not mixed with metal element graphite material. The material can be bonded to manufacture pipe spacers over 600MM in diameter. It has very excellent corrosion resistance to many acid, alkali, salts and organic compounds and heat transfer solutions, and even high temperature solutions. It does not melt, but will sublimate beyond 3,316℃. At high temperature conditions, the material should be carefully used in strong oxidizing media. In addition to its use, the material can also make non-metallic wrap in the gasket.

 9. Ceramic fiber, ceramic fiber formed in 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℃, which can make the non-metallic winding belt in the winding gasket.

10. PTFE concentrates the advantages of most plastic spacer materials, including temperature resistance ranging from-95℃ to 232℃. In addition to free fluorine and alkali metals, it has excellent corrosion resistance to chemicals, solvents, hydroxide and acids. The PTFE material can fill the glass, and its purpose is to reduce the cold flow and creep ability of PTFE.