Silicone rubber seals
The selection of sealing ring material is of great significance to its sealing performance and service life. The performance of the material directly affects the performance of the sealing ring.
NBR nitrile rubber sealing ring: suitable for use in petroleum hydraulic oil, glycol hydraulic oil, two ester lubricating oil, gasoline, water, silicon grease, silicone oil and other media. It is the most widely used and lowest cost rubber seal. Do not apply to polar solvents such as ketones, ozone, nitro hydrocarbons, MEK and chloroform. The general operating temperature range is -40~120 ℃.
HNBR hydrogenated nitrile rubber sealing ring: has excellent corrosion resistance, tear resistance and compression deformation characteristics, ozone resistance, sunshine resistance, weather resistance is good. It has better wear resistance than nitrile rubber. Suitable for washing machinery, automobile engine system and refrigeration system using new environmental refrigerant R134a. Do not use in alcohols, esters or aromatic solutions. The general operating temperature range is -40~150 ℃.
SIL silicone rubber sealing ring: excellent heat resistance, cold resistance, ozone resistance, atmospheric aging resistance. It has good insulation performance. But the tensile strength is worse than ordinary rubber and does not have oil resistance. Suitable for household appliances such as electric water heater, electric iron, microwave oven, etc. It is also suitable for all kinds of articles in contact with the human body, such as water bottles, drinking fountains and so on. Not recommended in most concentrated solvents, oils, concentrated acids and sodium hydroxide. The general operating temperature range is -55~250 ℃.
Four, VITON fluorine rubber sealing ring: high temperature resistance is better than silicon rubber, has excellent weather resistance, ozone resistance and chemical resistance, cold resistance is poor. Resistant to most oils and solvents, especially acids, aliphatic hydrocarbons, aromatic hydrocarbons and animal and vegetable oils. Suitable for diesel engines, fuel systems and chemical plant sealing requirements. Not recommended for ketones, esters of low molecular weight and mixtures containing nitrate. The general operating temperature range is -20~250 ℃.
Five, FLS fluorosilicone rubber sealing ring: its performance has the advantages of fluorosilicone rubber and silicone rubber, oil resistance, solvent resistance, fuel oil resistance and high and low temperature resistance are good. Resistant to oxygen - containing compounds, aromatic - containing solvents and chlorine-containing solvents. Generally used in aviation, aerospace and military applications. Exposure to ketones and brake oils is not recommended. The general operating temperature range is -50~200 ℃.
Six, EPDM EPDM rubber seal ring: has good weather resistance, ozone resistance, water resistance and chemical resistance. Can be used for alcohol and ketone, also can be used for high temperature water vapor environment seal. Suitable for bathroom equipment, car radiator and brake system. Not recommended for food use or exposure to mineral oils. The general operating temperature range is -55~150 ℃.
Seven, CR neoprene rubber sealing ring: sunshine resistance, weather resistance performance is particularly good. It is not afraid of refrigerant such as dichlorodifluoromethane and ammonia, and is resistant to dilute acid and silicone grease lubricating oil, but it has a large expansion in mineral oil with low aniline point. Easy to crystallize and harden at low temperature. Suitable for all kinds of atmospheric contact, sunlight, ozone environment and a variety of fire resistant, chemical corrosion resistant sealing environment. Not recommended for use in strong acids, nitrohydrocarbons, esters, chloroforms and ketones. The general operating temperature range is -55~120 ℃.
Eight, IIR butyl rubber sealing ring: air tightness is particularly good, heat resistance, sunshine resistance, ozone resistance, good insulation performance; Resistant to polar solvents such as alcohols, ketones, esters, etc., can be exposed to animal and vegetable oils or oxides. Suitable for chemical resistant or vacuum equipment. It is not recommended to use with petroleum solvents, kerosene or aromatic hydrocarbons. The general operating temperature range is -50~110 ℃.
Nine, ACM acrylic rubber sealing ring: oil has excellent resistance, high temperature resistance, weather resistance is good, but mechanical strength, compression deformation rate and water resistance is slightly poor. It is generally used in automobile transmission system and power steering system. Not suitable for hot water, brake oil, phosphate ester. The general operating temperature range is -25~170 ℃.
NR natural rubber sealing ring: it has good wear resistance, elasticity, tensile strength and elongation. However, it is easy to age in air and become sticky when heated. It is easy to expand and dissolve in mineral oil or gasoline. It is alkali resistant but not acid resistant. It is suitable for use in automobile brake oil, ethanol and other liquid with hydroxide ions. The general operating temperature range is -20~100 ℃.
Eleven, PU polyurethane rubber sealing ring: polyurethane rubber mechanical properties are very good, wear resistance, high pressure resistance are far better than other rubber. Aging resistance, ozone resistance, oil resistance is also quite good, but it is easy to hydrolysis at high temperature. Generally used for high pressure and wear resistant sealing links, such as hydraulic cylinders. The general operating temperature range is -45~90 ℃.
Twelve, metal rubber sealing ring: made of stainless steel wire, does not contain any rubber components, has a strong use characteristics. For example: in high vacuum, high and low temperature, strong radiation, and various corrosion and other environments to maintain normal work. Sealing ring skin according to the use of different materials such as stainless steel, copper, ptfe and other materials, coated metal rubber components as lining core, with high sealing strength, good effect, reusable and other advantages. Sealing ring lining core is made of different wire diameter, density components, suitable for different pressure occasions. The general use range is -80~800℃. This kind of sealing ring is more expensive because of its high cost. But good performance, a wide range of use environment, have been unanimously recognized by people.