Almost all the industrial applicants and machinery require a seal and O-ring, which is one of the most common types of seal that is used in a wide range of dynamic and static applications. One of the main reasons why this type of ring is so popular is its simple and straightforward design; it is made through well-developed rules of groove geometry and more importantly, it provides a reliable and economical sealing solution.
Typically, the oring seal is made up of an elastomeric circular cross section that is designed into a groove and thereby provides an initial compression. The force needed to compress this type of a seal is due to the cross section diameter and the durometer. This circular stretch of orings affect the compression capacity of seals and this, in turn, reduces the sealing capacity of the rings.
If you are using this type of seal in an application where the pressure level is very low or zero, the natural resiliency of the rubber compounds the seal. One of the best ways to increase the efficiency of this type of a seal is to expand or increase the diametrical squeeze. However, you need to remember that this technique works only for low-pressure application. Whereas, if you are using the seal in high-pressure dynamic applications, the increase in the squeeze can have an adverse effect on the machine, thus, lowering its performance.
If you are wondering why and how the diametrical squeeze of the rings affect the working of the machinery, then you must know that it plays a pivotal role in providing a frictional force between the ring and the groove that holds it in its position correctly and firmly. Irrespective of the type of the metal that the rings are made of, the groove is specially designed in a way that it acts as an agent which provides the initial force on the seal all across the axis.
When the pressure is applied, the rings will automatically move towards the low-pressure area of the groove and thus, the sealing pressure is transmitted to the surface that is to be sealed.
Now that you know how the ring functions, it would only help you to know how to choose the right ring material for your application? Choosing the right material is not as easy a task as it may sound. There are several factors that you need to consider, but two of the most important factors are the different chemicals that the rings would be exposed to and the operating temperature range for the rings. It is natural that if you are going to use the ring in a certain chemical application, then you need to choose a ring that would not react with the chemical. Some of the other vital factors that you need to consider are the resistance, abrasion, sunlight, and tearing. Each material has its own pros and cons so do your homework well before choosing the right ring for your application.