Analysis of the use pressure range of different materials and hardness O-rings

01Nitrile rubber (NBR) O-ring

When the hardness of the nitrile rubber O-ring ranges from 40-90±5 Shore A, its use pressure value increases with increasing hardness. Lower hardness O-rings are softer and suitable for low pressure and low stress sealing situations, while higher hardness O-rings are more suitable for high pressure applications. Here is a rough reference to the range of pressures used for different hardness O-rings:

A. Hardness 40±5 Shore A: Suitable for low pressure applications, usually can withstand pressure around 1-5 MPa (10-50 bar).

B. Hardness 50±5 Shore A: The pressure that can be tolerated is usually around 5-10 MPa (50-100 bar).

C. Hardness 60±5 Shore A: The pressure that can be tolerated is usually around 10-15 MPa (100-150 bar).

D. Hardness 70±5 Shaw A: The pressure that can be tolerated is usually around 15-20 MPa (150-200 bar).

E. Hardness 80±5 Shore A: The pressure that can be withstood is usually around 20-35 MPa (200-350 bar).

F. Hardness 90±5 Shore A: The pressure that can be withstood is usually around 35-50 MPa (350-500 bar).

02 Hydrogenated nitrile rubber (HNBR) O-ring

When the hardness of the hydrogenated nitrile rubber O-ring ranges from 55-90 Shore A, its use pressure value will usually increase with the increase of hardness. HNBR O-rings are superior to ordinary nitrile rubber (NBR) in terms of oil resistance, high temperature resistance and wear resistance, so they perform well in higher pressure applications. The following is a rough reference to the range of pressure used for HNBR O-rings of different hardnesses:

A. Hardness 55±5 Shore A: Suitable for low pressure applications, usually can withstand pressures around 5-10 MPa (50-100 bar).

B. Hardness 60±5 Shore A: The pressure that can be tolerated is usually around 10-15 MPa (100-150 bar).

C. Hardness 70±5 Shaw A: The pressure that can be tolerated is usually around 15-20 MPa (150-200 bar).

D. Hardness 80±5 Shore A: The pressure that can be tolerated is usually around 20-35 MPa (200-350 bar).

E. Hardness 90±5 Shore A: The pressure that can be tolerated is usually around 35-50 MPa (350-500 bar).

03 Ethylene propylene diene oxide rubber (EPDM) O-ring

When the hardness range of EPDM rubber O-ring is 40-90 Shore A, its use pressure value varies with the increase of hardness. EPDM O-rings are widely used in the automotive, industrial and construction industries due to their excellent weather resistance, ozone resistance and chemical corrosion resistance. The following is a rough reference to the range of pressure used for EPDM O-rings of different hardnesses:

A. Hardness 40±5 Shore A: Suitable for low pressure applications, usually can withstand pressure around 1-5 MPa (10-50 bar).

B. Hardness 50±5 Shore A: The pressure that can be tolerated is usually around 5-10 MPa (50-100 bar).

C. Hardness 60±5 Shore A: The pressure that can be tolerated is usually around 10-15 MPa (100-150 bar).

D. Hardness 70±5 Shaw A: The pressure that can be tolerated is usually around 15-20 MPa (150-200 bar).

E. Hardness 80±5 Shore A: The pressure that can be tolerated is usually around 20-25 MPa (200-250 bar).

F. Hardness 90±5 Shore A: The pressure that can be tolerated is usually around 25-35 MPa (250-350 bar).

It should be noted that although the EPDM O-ring has good weather resistance and chemical stability, its pressure resistance is weaker than that of fluororubber (FKM) and nitrile rubber (NBR). As a result, EPDM O-rings are often used more in medium and low pressure systems, especially in environments where high temperature resistance, UV resistance, or exposure to oxidizing chemicals are required.

04 Fluorine rubber (FKM) O-ring

When the hardness of the fluororubber O-ring ranges from 50-90±5 Shore A, its use pressure value is similar to that of nitrile rubber (NBR), and also increases with increasing hardness. Fluororubber has better resistance to high temperature and chemical corrosion and is suitable for use in harsh environments. The following is a rough reference for the range of pressure used for fluorine rubber O-rings of different hardnesses:

A. Hardness 50±5 Shore A: Suitable for low pressure applications, usually can withstand pressures around 5-10 MPa (50-100 bar).

B. Hardness 60±5 Shore A: The pressure that can be tolerated is usually around 10-15 MPa (100-150 bar).

C. Hardness 70±5 Shore A: The pressure that can be tolerated is usually around 15-20 MPa (150-200 bar).

D. Hardness 80±5 Shore A: The pressure that can be tolerated is usually around 20-35 MPa (200-350 bar).

E. Hardness 90±5 Shore A: The pressure that can be tolerated is usually around 35-50 MPa (350-500 bar).

05silica gel (Silicone) O-ring

When the hardness range of the silicone O-ring is 30-90 Shore A, its operating pressure value will generally increase with the increase of hardness. Due to the softness and high temperature resistance of the silicone material, silicone O-rings are generally suitable for medium and low pressure and sealing situations where greater elasticity is required. The following is a rough reference to the pressure range used for silicone O-rings of different hardnesses:

A. Hardness 30-40 Shore A: Suitable for low pressure applications, usually can withstand pressures around 1-3 MPa (10-30 bar).

B. Hardness 50 Shore A: The withstand pressure is usually around 3-7 MPa (30-70 bar).

C. Hardness 60 Shore A: The withstand pressure is usually around 7-10 MPa (70-100 bar).

D. Hardness 70 Shore A: The pressure that can be tolerated is usually around 10-15 MPa (100-150 bar).

E. Hardness 80 Shore A: The pressure that can be tolerated is usually around 15-20 MPa (150-200 bar).

F. Hardness 90 Shore A: The withstand pressure is usually around 20-25 MPa (200-250 bar).

06 Fluorosilicone rubber (FVMQ) O-ring

When the hardness of the fluorosilicone rubber (FVMQ) O-ring ranges from 45-80 Shore A, its use pressure value will increase with the increase of hardness. Fluorosilicone rubber combines the advantages of silicone rubber and fluororubber and has good high and low temperature resistance and chemical corrosion resistance, but its pressure resistance is generally inferior to other rubber materials such as hydrogenated nitrile rubber (HNBR) or fluororubber (FKM). Here is a rough reference to the pressure range of use of fluorosilicon O-rings of different hardnesses:

A. Hardness 45±5 Shore A: Suitable for low pressure applications, usually can withstand pressure around 1-5 MPa (10-50 bar).

B. Hardness 55±5 Shore A: The withstand pressure is usually around 5-10 MPa (50-100 bar).

C. Hardness 65±5 Shore A: The pressure that can be tolerated is usually around 10-15 MPa (100-150 bar).

D. Hardness 75±5 Shore A: The pressure that can be tolerated is usually around 15-20 MPa (150-200 bar).

E. Hardness 80±5 Shore A: The pressure that can be tolerated is usually around 20-25 MPa (200-250 bar).

07tetraprofluororubber (AFLAS)

Tetrapropylene fluoride rubber (AFLAS), also known as perfluorinated rubber, is a high-performance material with extremely high chemical stability and high temperature resistance. When the hardness range of its "O-ring" is 60-90 Shore A, the pressure it can withstand is usually high, and as the hardness increases, its pressure resistance will also improve. Here is a rough reference to the pressure range of use of tetraprofluorine O-rings of different hardnesses:

A. Hardness 60±5 Shore A: Suitable for medium pressure applications, usually the withstand pressure is around 10-15 MPa (100-150 bar).

B. Hardness 70±5 Shore A: The pressure that can be withstood is usually around 15-20 MPa (150-200 bar).

C. Hardness 80±5 Shore A: The pressure that can be withstood is usually around 20-30 MPa (200-300 bar).

D. Hardness 90±5 Shore A: The pressure that can be withstood is usually around 30-40 MPa (300-400 bar).

08 perfluoroether O-ring (FFKM, perfluoroether elastomer)

When the hardness range of the perfluoroether rubber O-ring is 75-90 Shore A, its operating pressure value is usually high, and as the hardness increases, the pressure resistance performance will be improved accordingly. Perfluoroether rubbers are known for their superior chemical and high temperature resistance for use in extremely demanding environments. The following is a rough reference to the range of pressure used for PFether O-rings of different hardnesses:

A. Hardness 75±5 Shaw A: Suitable for medium and high pressure applications, usually the withstand pressure is around 20-30 MPa (200-300 bar).

B. Hardness 80±5 Shaw A: The pressure that can be tolerated is usually around 30-35 MPa (300-350 bar).

C. Hardness 90±5 Shore A: The pressure that can be tolerated is usually around 35-40 MPa (350-400 bar).

These pressure values are based on reference values for typical applications:

The pressure resistance in actual use also needs to consider specific working conditions, such as the size of the O-ring, medium, temperature and sealing design, etc. If the application situation involves high pressure or extremely harsh conditions, it is recommended to conduct special testing or refer to the manufacturer's technical information to ensure that the O-ring can meet the application needs