The permanent elasticity of O-rings has made o-rings a popular seal for many applications. Used correctly, it forms the basis of modern sealing technology and is often recommended in these applications.
O-ring is a continuous ring, generally in circular cross section using elastomer material in its construction. Its dimensions are specified as inner diameter and section thickness.
O-rings are produced from many different rubber materials and many different chemical compounds. PTFE-based O-rings are highly resistant to the environment in extreme conditions (thermal or chemical).
O-ring Static Applications:
What makes the O-rings a sealing element is the elastic deformation capability of the cross section designed in accordance with its seat. The pressure of the sealed fluid also squeezes the o-rings. Thanks to its elastomer structure, the pressure load on it can be effectively distributed. Its main characteristics are:
-Wide pressure and temperature range
-Suitable for almost all liquids and gases
- Space saving
-Easy assembly, de-assembly
It is resistant to all pressures produced in practice. Elastomer o-rings behave like a hydraulic fluid, so the real question is the allowable pressure strictly related to the height of the seal seat. If it is certain, it should be supported with support rings produced with suitable material and design.
The temperature range may vary depending on the material used. Thanks to these materials, a wide scale is available between -130 ° C and + 320 ° C.
O-ring Hardness Selection:
The hardness of the O-rings is between 50-90 Shore A. Hardness increases as you go from low to high. Generally, the optimum 70 +/- 5 Shore A hardness grade used for elastomers. O-rings used in medium hardness have high elasticity, easy compressibility and more sealing properties against applications involving contact with rough or hard surfaces, gases, low temperatures and low compression force. Its 80-90 Shore A hardness is ideal for dynamic applications, however it has a low friction force.
O-ring assembly:
Chamfered or rounded areas are required for O-ring mounting. It should never be pushed into sharp edges, threaded places, angular holes, keyways, hard or rough surfaces. If the areas to be used are like these, these points should definitely be covered. During assembly, o-rings should not be turned and should not be subjected to any circular movement.
In pneumatic applications, o-rings can also be installed unfixed, with low friction and long working life. The outer diameter of the mounted o-ring provides a perfect seal with insignificant compression. Therefore, the outer diameter of the o-ring should be equal to the diameter of the channel in the cylinder or maximum 3% more. The system pressure increases this insignificant compression and increases the sealing effect as it closes more between the o-ring and the cylinder.
O-ring Dynamic Applications:
It is possible to use O-rings in applications under low stress conditions (low temperature, low pressure, etc.). Lubrication is essential. What makes the O-rings a sealing element is the elastic deformation of the cross section designed in accordance with its seat. The pressure of the sealed fluid also squeezes the o-rings. Thanks to its elastomer structure, the pressure load on it can be effectively distributed. Its main characteristics are:
-Wide pressure and temperature range
-Suitable for almost all liquids and gases
- Space saving
-Easy assembly, de-assembly
It has a linear strength up to 5MPa. It is recommended to use with support rings at higher pressures.
There is short circular and linear motion in lubricated and / or coated ones. It has rotation and linear speed up to 0.5m / s.
The temperature range may vary depending on the material used. Thanks to these materials, a wide scale is available between -130 ° C and + 320 ° C.
70 +/- 5 Shore A hardness is the optimum mechanical property for many elastomers. Low friction force
Thanks to its 80-90 Shore A hardness, it is ideal for dynamic applications.
