What Causes an O-Ring To Fail?

16 December 2021
 Categories: , Blog


O-rings are widely used wherever an industrial process calls for the transmission fluids under pressure. Engineers claim that they are the best solution due to their "elastomeric" properties and will typically put up with temperature and pressure extremes very well. However, these simple products can sometimes fail, and it may be challenging to find out why. So, if you're encountering a problem, how can you get to the bottom of it?

How the Humble O-Ring Works

In simple terms, "elastomeric" means that the product is able to regain its original shape whenever any load is removed. In other words, the o-ring, which is typically made from natural or synthetic rubber, can compress to form a perfect seal between two other components and then rebound thereafter.

As the o-ring compresses, it will expand to fill the void (or gland) between the two features. The seal should then ensure that liquids or gases remain within the system and do not leak out.

It's nevertheless important to ensure that the connection between the two individual components is properly designed. If this is not the case, then the ring may not be able to spread out properly under compression or may simply be unable to fill the expected space.

It is also important, of course, to choose the proper size o-ring and ensure that it is made from the right materials for the job. This will depend on the liquid or gas being transported.

Common Problems

When you encounter a problem, you may need to become a detective. Remove the o-ring and have a close look at it for any signs of failure. If you can see that the inner or outer side of the ring has flattened out, you may have chosen the wrong product for the job. It may not be very resistant to heat, or you may be putting too much pressure on the gland to try and achieve the correct seal.

Alternatively, if you can notice damage around the periphery where tiny bites or chunks have been taken out of the ring, this may also indicate that the material is too soft. It may not be able to cope with the nature of the fluid passing through, and this may be causing degradation. Alternatively, the o-ring itself may be too large for the internal diameter of the gland.

Where To Turn Next

If you require any additional guidance to help you understand why your o-rings are failing, turn to the experts. Reach out to an o-ring manufacturer or a technician who has widespread experience in this area.