Proper selection of the hardness of the O-ring is critical to ensure tightness and reliability. Linde Polymer will introduce you to the importance of hardness selection and its selection suggestions, hoping that you can choose the appropriate hardness according to your actual needs.
Hardness concept and testing method
Definition of hardness: The hardness of the rubber sealing ring refers to its own resistance under the action of external force, which can also be understood as its elastic characteristics. Hardness values are usually expressed in units such as “Shore A” or “Shore D “.
Test method: Hardness test is done by hardness tester. Commonly used hardness testers are Shore A durometer and Shore D durometer. The needle tip of the hardness tester will press into the surface of the rubber sealing ring to a certain depth, and then read the depth entered by the needle tip to obtain the hardness value.
The importance of hardness selection of rubber O-ring and its selection suggestions
The importance of hardness selection
- Resistance to compression deformation: Rubber O-rings may undergo compression deformation under long-term pressure, especially in high-pressure or high-temperature environments. Appropriate selection of hardness can reduce the occurrence of compression deformation and ensure sealing and service life.
- Salability: its own hardness will directly affect its deformation and rebound ability after compression. Rubber sealing rings with too low hardness are prone to excessive deformation, resulting in insufficient sealing performance, resulting in leakage and damage.
- Wear resistance: Rubber sealing rings with higher hardness usually have better wear resistance and oil resistance, and are suitable for some applications under high wear and severe working conditions.
Factors Affecting the Selection of Rubber Sealing Ring Hardness
Working pressure: The working pressure directly impacts the compression deformation of the sealing ring. In high-pressure environments, it is necessary to choose rubber sealing rings with lower hardness to reduce compression deformation and maintain sealing. In a low-pressure environment, a rubber sealing ring with higher hardness can be selected to improve its elasticity and resilience.
Media properties: Different media have different hardness requirements for rubber materials. For example, oil-related media require O rubber sealing rings with good oil resistance, and materials with higher hardness are often selected.
Working temperature: Working temperature is one of the important factors in selecting the hardness of rubber sealing rings. Rubber frequently hardens in high-temperature environments, so you need to pick a lower-hardness rubber seal to maintain its sealing properties. In low- temperature environments, rubber will become softer, and a rubber sealing ring with higher hardness needs to be selected to improve its elasticity and cold resistance.
Service Life: Service life is a significant consideration in hardness selection. Too high or too low hardness will affect the service life of the rubber seal. Reasonable selection of hardness can extend the service life of rubber sealing rings.
Suggestions on the selection of rubber O-ring hardness
- Regular testing: Regularly testing the hardness of rubber O-rings is the key to ensuring stable performance. The test results can be used as a basis for adjusting the hardness selection.
- Select reliable manufacturers: Choose reliable rubber product manufacturers to ensure that they provide O-rings that meet standard requirements and have accurate and reliable hardness values.
- Decide according to actual needs: Choose a rubber sealing ring of appropriate hardness according to the specific working environment, temperature, pressure, medium and other requirements.
It can be known that the hardness value directly impacts the sealing, pressure resistance and wear resistance of the rubber O-ring. When customers select rubber sealing rings, they should fully understand the concept of hardness and testing methods, and make correct hardness s elections based on actual needs to ensure that the hardness of the selected rubber sealing rings meets the standard.
