The compressibility of the O-ring refers to the proportion of the reduction of the section diameter of the O-ring after the compression force is applied. It is an important performance parameter that affects the sealing effect and service life of seals. The following is a detailed explanation of the O-ring compression rate: 1. Calculation formula
The formula for calculating the compression ratio of O-ring is: compression ratio (W)= (DO-h)/do × 100%. Where, do represents the section diameter of the O-ring in the free state (mm), h represents the distance between the bottom of the O-ring groove and the sealed surface, that is, the section height of the O-ring after compression (mm).
2. Select the scope
The selection of O-ring compression rate varies according to application scenarios and working conditions. Here are some common options:
Static sealing device: Generally choose 15%~30% compression rate to ensure a good sealing effect.
Reciprocating motion sealing: a compression rate of 10% to 15% is usually selected to meet the sealing needs of reciprocating motion.
Rotary motion seal: Joule heat effect must be taken into account when selecting the compression rate. Generally speaking, the compression rate of the rotary motion seal is also selected to be 10% to 15%. However, it should be noted that when O-rings are used for rotary motion seals, they are limited to low-speed rotary seals.
3. Influencing factors
Working pressure: The greater the working pressure, the greater the required compression rate may be to ensure the sealing effect.
Properties of the medium: the temperature, corrosiveness, viscosity of the medium will also affect the compression rate selection of the O-ring. For example, high temperature media may cause the O-ring material to expand, so the compression rate needs to be properly adjusted.
Material hardness: The material hardness of the O-ring also affects its compression performance. When the O-ring with higher hardness is compressed, the deformation may be smaller, so a higher compression rate is required to achieve the ideal sealing effect.
4. Precautions
When installing O-rings, ensure that they are properly placed in the groove and avoid over-stretching or compression.
Regularly check the sealing effect of the O-ring, such as leakage or damage, should be replaced in time.
According to different application scenarios and working conditions, reasonable selection of O-ring material and compression rate to ensure its sealing performance and service life.
The compression rate of O-ring is an important performance parameter, and its selection should be determined according to the specific application scenario and working condition. Through reasonable selection and installation, it can ensure that the O-ring plays a good sealing role in the mechanical equipment.