Different types of sealing rings have their own characteristics in sealing performance due to differences in structure and materials, and are suitable for different working conditions. The following are several common types of sealing rings and their differences in sealing performance:
O-ring: This is a common and widely used type of sealing ring. It is a rubber ring with a circular cross-section that achieves sealing through elastic deformation generated by pre compression. In static sealing, O-ring seals can provide good sealing performance over a wide pressure range (up to tens of megapascals) and have good sealing ability for various media such as water, oil, and gas. In terms of dynamic sealing, it is suitable for low-speed, medium pressure rotation or reciprocating motion, such as piston sealing of hydraulic cylinders. However, the disadvantage of O-ring seals is that they are prone to extrusion deformation under high pressure, leading to seal failure. Therefore, they often need to be used in conjunction with retaining rings in high-pressure situations. In addition, its frictional resistance is relatively high, making it unsuitable for high-speed sealing.
Lip seal ring: The cross-sectional shape of a lip seal ring is similar to that of a lip, and it uses the tight fit between the lip and the sealing surface to achieve sealing. Common types include Y-shaped, V-shaped, U-shaped, etc. Lip seals perform well in dynamic sealing and are suitable for sealing reciprocating motion, such as piston rod sealing in hydraulic systems. Its sealing performance increases with the increase of pressure, as pressure makes the lips more tightly adhere to the sealing surface. Lip seals have the ability to compensate for wear and tear, and can still maintain sealing effectiveness to a certain extent even after lip wear. However, the installation direction of the lip seal ring is very important, and it is necessary to ensure that the lip faces the pressure source, otherwise it will reduce the sealing performance. In addition, it has high requirements for the surface roughness of the sealing surface, and uneven surfaces can affect the sealing effect.
Rotating shaft lip seal ring (oil seal): specially used for sealing rotating shafts to prevent lubricating oil leakage and external impurities from entering. Oil seals are usually made of rubber with a metal frame to increase strength. Its sealing lip is in close contact with the surface of the rotating shaft, forming a seal. Oil seals are suitable for lower pressures and higher rotational speeds, with a general linear speed of around 15-20 meters per second. It has a good sealing effect on lubricating oil, but it requires strict coaxiality and surface roughness of the sealing surface. Eccentricity or surface roughness of the shaft can accelerate oil seal wear and seal failure. In addition, the temperature resistance of oil seals is relatively limited, and rubber is prone to aging and hardening at high temperatures, which affects the sealing performance.
Combination sealing ring: composed of two or more components made of different materials or structures, combining the advantages of different components to improve sealing performance. For example, a Glay ring is composed of polytetrafluoroethylene (PTFE) slip rings and rubber elastomers. PTFE slip rings have low friction coefficients and good wear resistance, while rubber elastomers provide elastic preload force. Combination sealing rings are suitable for harsh working conditions such as high pressure, high speed, and high temperature, with reliable sealing performance and long service life. It is widely used in hydraulic and pneumatic systems, such as the piston and piston rod seals of hydraulic cylinders. However, the structure of the composite sealing ring is relatively complex, the cost is high, and installation and maintenance also require * * technology and experience.
Metal sealing ring: usually made of metal materials such as stainless steel and copper alloy, it has the characteristics of high strength, high temperature resistance, and high pressure resistance. Metal sealing rings are suitable for sealing high-temperature, high-pressure, high vacuum, and highly corrosive media, such as key equipment in aerospace, chemical, energy, and other fields. It achieves sealing through plastic deformation of the metal surface, with reliable sealing performance and the ability to withstand high pressure and temperature. However, the sealing surface of the metal sealing ring requires high-precision processing, and high cleanliness and fit requirements are placed on the sealing surface during installation, otherwise leakage is prone to occur. In addition, the cost of metal sealing rings is relatively high and they are not suitable for situations with frequent vibration and impact.
Rubber gasket: mainly used for static sealing, such as sealing flange connections, pipe joints, and other parts. The sealing performance of rubber gaskets depends on the material, thickness, and compression capacity of the gasket. Gaskets made of different rubber materials have different tolerances to different media, such as nitrile rubber gaskets suitable for oil media and fluororubber gaskets suitable for chemically corrosive media. The advantages of rubber gaskets are easy installation and low cost, but they are prone to aging and deformation after high pressure, high temperature, or long-term use, leading to a decrease in sealing performance.
Different types of sealing rings have their own advantages and disadvantages in terms of sealing performance. When selecting, it is necessary to consider specific working conditions such as medium, pressure, temperature, and movement mode comprehensively to ensure that the sealing ring can provide reliable sealing effect.
