O-ring is the most widely used sealing ring in production and life. It is cheap, easy to use, and has various materials, so it is widely used.

The cross section of the O-ring is circular, so it is called an O-ring. Due to friction issues, O-seals are usually only used for static seals and low pressure pneumatic seals.

O-rings for common materials:

NBR nitrile rubber sealing ring 

Suitable for use in petroleum-based hydraulic oil, glycol-based hydraulic oil, diester-based lubricating oil, gasoline, water, silicone grease, silicone oil and other media. It is the rubber seal with the most uses and the lowest cost at present. Not suitable for use in 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 

It has excellent corrosion resistance, tear resistance and compression deformation resistance, and has good ozone resistance, sunlight resistance and weather resistance. Better abrasion resistance than nitrile rubber. Suitable for washing machinery, automobile engine system. Not recommended for use in alcohol, ester or aromatic solutions. The general operating temperature range is  -40~150 ℃. 

SIL Silicone Rubber Seal 

It has excellent heat resistance, cold resistance, ozone resistance and atmospheric aging resistance. Has good insulating properties. However, the tensile strength is poorer than that of general rubber and it does not have oil resistance. Suitable for household appliances such as electric water heaters, electric irons, microwave ovens, etc. It is also suitable for all kinds of supplies that have contact with the human body, such as kettles, water dispensers, etc. Not recommended for use in most concentrated solvents, oils, concentrated acids and sodium hydroxide. The general operating temperature range is -55~250 ℃.

 VITON fluorine rubber sealing ring

 High temperature resistance is better than silicone rubber, excellent weather resistance, ozone resistance and chemical resistance, but poor cold resistance. Resistant to most oils and solvents, especially acids, aliphatic hydrocarbons, aromatic hydrocarbons and animal and vegetable oils. Suitable for sealing needs of diesel engines, fuel systems and chemical plants. Not recommended for use with ketones, low molecular weight esters and nitrous-containing mixtures. The general operating temperature range is -20~250 ℃. 

FLS fluorosilicone rubber sealing ring

It has the advantages of both fluororubber and silicone rubber, and has good oil resistance, solvent resistance, fuel oil resistance and high and low temperature resistance. Resistant to oxygen-containing compounds, aromatic hydrocarbon-containing solvents and chlorine-containing solvents. The general operating temperature range is -50~200 ℃. 

EPDM EPDM rubber sealing ring 

It has good weather resistance, ozone resistance, water resistance and chemical resistance. It can be used for alcohols and ketones, and can also be used for sealing in high temperature water vapor environment. The general use temperature range is -55~150 ℃. 

CR neoprene seal ring 

Sunlight and weather resistance are particularly good. Not afraid of refrigerants such as dichlorodifluoromethane and ammonia, resistant to dilute acid and silicone grease-based lubricating oil, but has a large expansion amount in mineral oil with low aniline point. It is easy to crystallize and harden at low temperature. It is suitable for all kinds of environments exposed to the atmosphere, sunlight and ozone, as well as various flame-resistant and chemical-resistant sealing links. Not recommended for use with chemicals such as strong acids, nitro hydrocarbons, esters, chloroform and ketones. The general operating temperature range is -55~120 ℃. 

IIR Butyl Rubber Seal 

Especially good air tightness, heat resistance, sunlight resistance, ozone resistance, good insulation performance; good resistance to polar solvents such as alcohols, ketones, esters, etc., can be exposed to animal and vegetable oils or oxidizable. Suitable for chemical resistant or vacuum equipment. Not recommended for use with petroleum solvents, kerosene or aromatic hydrocarbons. The general operating temperature range is -50~110 ℃.

ACM acrylic rubber sealing ring 

It has excellent resistance to oil, high temperature resistance and weather resistance, but its mechanical strength, compression deformation rate and water resistance are slightly poor. Generally used in automobile transmission system and power steering system. Not suitable for hot water, brake fluid, phosphate ester. The general operating temperature range is -25~170 ℃. 

NR natural rubber sealing ring

Rubber products have good wear resistance, elasticity, breaking strength and elongation. However, it is easy to age in the air, becomes sticky when heated, swells and dissolves easily in mineral oil or gasoline, and is resistant to alkali but not strong acid. It is suitable for use in automobile brake fluid, ethanol and other liquids with hydroxide ions. The general operating temperature range is -20~100 ℃.

PU polyurethane rubber sealing ring   

The mechanical properties of polyurethane rubber are very good, and the wear resistance and high pressure resistance are far superior to other rubbers. The aging resistance, ozone resistance and oil resistance are also quite good, but it is easy to be hydrolyzed at high temperature. Generally used for high-pressure, wear-resistant sealing links. The general operating temperature range is -45~90 ℃.

Because of its high hardness, strong extrusion resistance and good wear resistance, it has become more and more widely used in recent years.

Metal O-ring    

The material of the metal sealing ring is generally stainless steel or copper.

O-rings made of stainless steel pipes are often used for high vacuum or high temperature sealing, and the temperature is up to 300°C-800.

Copper seals have been widely used in hydraulic sealing in the early years, especially in high pressure or high temperature conditions, mainly using the characteristics of soft copper, corrosion resistance and high temperature resistance. Due to the high price and non-reusability, It is not resistant to vibration, so it is rarely used at present.