What are the types of O-ring seals?
According to the actual use, they can be divided into seals for fixed sealing, seals for reciprocating motion sealing, and seals for rotary motion sealing.
According to its sealing method, it can be divided into radial sealing and axial sealing. Radial sealing can be subdivided into seals for dynamic sealing and seals for static sealing. In contrast, axial sealing can be subdivided into seals for internal and external pressure sealing.
What are the characteristics?
①Its sealing groove structure is very simple, its size is small, and the installation location is compact.
②It can achieve bidirectional sealing and is also suitable for dynamic sealing and static sealing.
③It has a self-sealing function and does not require periodic adjustment.
④The resistance of dynamic friction is relatively small, so it can also be used on occasions with alternating pressure.
⑤It has strong adaptability, flexible use, and a wide range of uses.
⑥It is cheap and has good interchangeability.
What factors should be considered when selecting O-ring seals?
1. The impact of materials
① Determine whether the working state of the equipment is continuous or intermittent. Different working hours will produce different impact loads on the sealing parts.
② The working pressure also affects the seal.
③ The impact of the working medium on the sealing effect, such as whether the working medium is gas, liquid, or other.
④ The impact of factors such as price and quality.
⑤ The working temperature also has a great impact on the seal. Generally speaking, acrylic rubber or fluoro rubber has better heat resistance, copolymerized chlorohydrin rubber has better cold resistance, and chloroprene rubber has better weather resistance and ozone resistance.
2. The impact of the use environment
① Working medium and working conditions. When selecting the raw materials of O-ring seals, you should ensure that they are compatible with the working medium, and then consider the specific working conditions such as pressure, temperature, working time, and operating cycle of the sealing part.
② Sealing form. There are many types of sealing forms, such as hole seals, shaft seals rotating shaft seals, static seals, dynamic seals, etc. The sealing effects of different sealing forms are different.
③ In addition, factors such as the hardness, pre-compression amount, extrusion gap, compression permanent deformation, stretching, and compression of the seal will also affect the actual sealing effect of the seal, which needs to be considered clearly.
How to prevent seal extrusion?
When the pressure or gap exceeds the limit of the seal itself, a retaining ring should be used. When pressure is applied from two directions, the retaining ring should be installed on both sides of the seal. If pressure is applied in one direction, the retaining ring needs to be installed on the side opposite to the applied pressure.
What are the design standards?
Before production, seal manufacturers need to design them. The design needs to be by standards, such as American Standard-AS568, Japanese Standard-V.S.P.G, Chinese Standard-C92, and British Standard-BS1516. Among them, the Japanese standard is further subdivided into JIS P series, JJIS V series, NOK S series, etc.
What are the application ranges?
Its application range is very wide, especially in agricultural machinery, metallurgical machinery, petroleum machinery, engineering machinery, aerospace equipment, construction machinery, plastic machinery, chemical machinery, and other fields.
To sum up, we can know that there are many knowledge points about O-rings. If you want to use this seal correctly, you still need to spend time studying and understanding its types, characteristics, selection, and application range.
