A rubber ring with a doughnut (torus) shape, the O-ring is a mechanical gasket that creates a seal to prevent unwanted leakage of gases or liquids. O-rings can be used in a variety of applications in many different environments, ranging from the extreme cold and pressure of outer space to the high temperatures and vibration of automotive engines. They can be found in the smallest engine parts to the largest aerospace components.
The most common use for an O-ring is to act as a simple gasket between two other components in order to prevent the escape of fluids or gases. The pliable nature of O-rings allows them to be easily installed into a gap and then compressed between the faces, forming a solid seal. This is very similar to how a cork or paper gasket would work, however O rings are generally more reliable and can be used in higher-pressure situations than traditional types of gaskets.
There are a number of different variables that affect how well an O-ring works, the most important being the type of environment in which it will be used. Some production environments may involve (extreme) hot or cold temperatures that could change the elasticity of the rubber material. This can cause the O-ring to lose its pliability, which will impact on its ability to create a proper seal. Other factors include the type of medium into which the O-ring will be exposed, such as solvents, chemicals or grease. Not all rubber materials will react well to these substances, so it is crucial to know exactly what the O-ring will be sealing before selecting the correct material.
Another factor that can influence an O-ring's performance is the amount of friction it generates. The hardness of the rubber is a direct effect on this, with softer rubber having a higher coefficient of friction than harder rubber. When O-rings are sealing a moving component it is important that the amount of friction is kept to a minimum in order to maximize efficiency.
The size of an O-ring is also an important consideration. It is essential to ensure that the O-ring fits into the groove in which it will be seated, and that the groove is wide enough to allow the O-ring to fully seat within it. If an O-ring is seated into a groove that is too narrow it will not be able to properly compress and lose its ability to create a seal.
O-rings are available in a wide range of metric and standard inch sizes to cater for any application. They can be made from a variety of elastomer materials, all of which are designed to cope with the specific demands of any given application environment. These factors can include temperature, chemical compatibility, lubrication requirements, longevity and pressure. By choosing the right o-ring for your application and taking all of these variables into consideration, you can be sure that it will be able to perform at its best in even the most challenging environments.