How much do you know about the classification of rubber seals?
According to the working mode and the relative movement of the joint surfaces, seals can be divided into two categories: static seals and dynamic seals.
static seal
1. Point sealing: Sealing is achieved by using point seals such as gaskets or O-rings on the joint surface, and is suitable for relatively stationary joint surfaces. For example, gasket seals at bolted joints.
Commonly used seals include:
Gasket: A gasket is a flat sealing element usually made of soft materials such as rubber, cardboard, metal, etc. The shape of the gasket can be round, square, oval, etc., and it achieves the sealing effect by forming point-shaped sealing areas on the joint surface.
O-ring: An O-ring is an annular rubber seal with a circular cross-section. O-rings have good elastic recovery properties and can fill the tiny gaps in the joint surface when compressed to form a seal. O-rings are widely used in various sealing situations, such as pipe connections, valves, pumps, etc.
Advantages of point seals include simplicity, ease of installation and replacement, and adaptability to joint surfaces of different shapes and sizes. It provides an effective seal at relatively low pressures, but at high pressures or temperatures, other types of sealing may be required.
When selecting a point seal, it is necessary to consider the corrosion resistance, temperature resistance, pressure resistance and compatibility of the sealing material with the medium to be sealed. In addition, the size, hardness and compression of the gasket or O-ring also need to be selected based on the specific application requirements.
2. Glue sealing: Use adhesive or sealant to fill the tiny gaps between the joint surfaces to form a seal. Common applications are adhesive sealing in construction, automotive and other fields.
3. Contact sealing: Sealing is achieved through close fit of the contact surfaces. Common contact seals include piston rings, O-rings and hydraulic seals.
The following are some common contact sealing methods
- Piston Ring: A piston ring is a piston seal used for reciprocating motion, commonly found in equipment such as internal combustion engines, compressors, and hydraulic cylinders. Piston rings are usually made of metal materials and are wear-resistant and high-temperature resistant. They can form an effective seal between the piston and the cylinder to prevent gas or liquid leakage.
- O-ring: The O-ring forms an annular sealing area on the joint surface and achieves sealing through compression deformation. O-rings are usually made of rubber or elastic materials. They have good sealing performance and elastic recovery and are widely used in pipe connections, valves, pumps and other equipment.
- Hydraulic seal: Hydraulic seal is used for sealing in hydraulic systems and often includes sealing rings, guide rings and support rings. Hydraulic seals achieve sealing through contact with the piston or piston rod, which can provide reliable sealing performance under high pressure conditions and prevent leakage of the hydraulic system.
The advantages of contact sealing include better sealing performance and reliability, and are suitable for sealing requirements under high pressure, high temperature and harsh working conditions. However, contact seals also have problems with wear and friction, so the wear resistance and lubrication conditions of the material need to be considered when selecting a contact seal to extend the service life of the seal.
Depending on the working pressure, static seals can be further classified into medium and low pressure static seals and high pressure static seals.
- Medium and low pressure static seals: Medium and low pressure static seals are suitable for relatively low working pressure ranges. In medium and low pressure static seals, the commonly used sealing materials are softer and the seals are usually wider gaskets. This sealing method uses the elastic deformation of the gasket to fill the gap on the joint surface, thereby achieving the sealing effect. Medium and low pressure static seals are commonly used in pipe connections, container lids and other applications.
- High-pressure static seal: High-pressure static seal is suitable for higher working pressure ranges. In high-pressure static seals, the commonly used sealing materials are relatively hard, and the seals are usually metal gaskets with narrow contact widths. Metal gaskets can provide better sealing performance under high pressure. High-pressure static seals are commonly used in automotive engines, compressors, high-pressure vessels and other applications.
The choice of medium and low pressure static seals or high pressure static seals depends on the working pressure requirements. For lower pressure ranges, medium and low pressure static seals are an economical and effective choice. In high-pressure environments, harder materials and closer contact are needed to ensure reliable sealing performance.
It is important to note that the specific pressure range can vary depending on the application and industry. Therefore, when selecting a sealing solution, the appropriate sealing type and material should be determined based on the actual working pressure and application requirements.
